Volume 1 - History and Fundamentals
Volume 1 - History and Fundamentals
Volume 1 - History and Fundamentals
~-~~ ~
\;
t ~ -
,_
Nathan Myhrvo ld
with Chris Young
and Maxime Bilet
Photograp hy by
ISBN: 978-0-9827610-0-7
First edition, 2011
Volume 1
viii
ix
VOLUME I:
HISTORY AND FUNDAMENTALS
2
CHAPTER 1: HISTORY
Origins of Cooking ........ .............................................. 6
Evolution and Revolution ........................ .......... ....... 14
The Seeds of Modernism .. ...... .... ..... .............. ........... 33
The Modernist Revolution ......... ........ .......... ..... ... .... 52
The Story of this Book .. .......................... .................. 83
About the Recipes ......... .................. ......................... 93
102
162
166
174
182
190
196
208
260
292
VOLUME2:
TECHNIQUES AND EQUIPMENT
CHAPTER 7: TRADITIONAL COOKING
Grilling ......................................................................... 7
Broiling .................. ....... .................... .... ... ................ .. 18
Roasting ..................................................................... 28
Panfrying a Ia Plancha .. ....... ................. ..................... 3 7
Sauteing ... .. ............................................................ ..... 44
Stir-Frying .......... ........ ... ............................. ................ 48
Covered Sauteing ................................... ........ ........ .... 58
Boiling ..................... ................... ..... ... ... ..... ........ ... .... . 63
Steaming ......................................... ................ ............ 70
Canning ................... ... ... .... ................. ... ..... ..... ... ....... . 75
Pot-Roasting and Stewing ......................................... 93
Baking ......... ....................... ....................................... 101
Cooking in Oil ......................................................... 11S
Smoking .............. .... ... .... ...... .............. ... .. .... ........... .. 132
150
192
280
VOLUME3:
ANIMALS AND PLANTS
CHAPTER 11: MEAT AND SEAFOOD
How Muscle Works ................................. .................... 6
Converting Muscle into Meat.. ................................. 32
Cutting ...................... ............................ ... ... ............. .. 44
Cooking Meat and Seafood ............................... .... .. .. 70
Cooking Skin and Innards .. ...................... .... ....... ... 116
Salting and Drying .... .......... .............. .... ................ .. 152
Marinating ............. .... ........ .... ................ .... .... .......... 190
Smoking ..... ..... .. .. ..... ... ... ... ... .. .. ...... ... ..... ........ .......... 208
Restructuring ... ....... ................................................. 220
258
VOLUME4:
INGREDIENTS AND PREPARATIONS
CHAPTER13:THICKENERS
64
196
240
316
CHAPTER18:COFFEE
354
viii
40
Potau-Feu
Hungarian Beef Goulash
106
140
Steamed Snapper
Hawaiian Poke
178
Shrimp Cocktail
Lobster Amfricaine
Tha i Crab Miang
Pulpo a Ia Gallega
Shellfish Omakase
Oyster Stew
208
Oeufs en Meurette
222
Cocoa Tajarin
Spaghetti aile Vongole
Russian Pelmeni
Paella Valenciana
Astronaut Ramen
Shanghai Soup Dumplings
258
Onion Tart
Lentil Salad
Sweet Pea Fricassee
Strawberry Gazpacho
Crispy Cau liflower
Watermelon Bulgogi
IV
v
XXX
XLVI
Foreword
When I saw the first sections of this book as it was
rigor.
As I read the book, two thoughts spring to
the future.
Ferran Adria
Roses, Spain
July2010
viii
Foreword
Over the road from my restaurant, the Fat Duck,
accepted.
accessible fashion.
I've long thought that the astonishingly rapid
Heston Blumenthal
Bray, England
July 2010
FOREWORDS
ix
in economics, another master's degree in geophysics and space physics, and a bachelor's degree in
a software project with some friends from graduate school. By the end of the summer, venture
MODERNIST CUISINE
France.
well.
Chef school was also quite an experience.
The writing I did for that eGullet thread ultimately led to this book. In another twist of fate,
Nathan Myhrvold
X j
English in England!
anyway.)
As I look back on it, a career in the kitchen
becoming a chef.
xi i
MODERN I ST CUISINE
MaximeBilet
xi i i
1 HISTORY
ORIGINS
OF COOKING
EVOLUTION AND
REVOLUTION
14
THE SEEDS OF
MODERNISM
33
THE MODERNIST
REVOLUTION
52
THE STORY OF
THIS BOOK
83
ABOUT
THE REC I PES
93
1
HISTORY
Our hunter-gatherer ancestors
HI STORY
ORIGINS OF COOKING
Nobody knows who the first cook was, but at some
about it.
plants did.
VO LU ME 1
1
Agriculture also enabled the development of
civilization. For the most part, hunter-gatherers
could not stay in one place very long, nor could
they live together in large numbers. Agriculture
changed that. Farm fields needed to be tended, so
farmers had to stay put. Agriculturalists needed
permanent buildings for homes and other uses. In
response, cities and towns sprang up.
Because agriculture freed at least some of
society from the task of providing food, people
began to spend time doing other things. Visual
arts existed before civilization, as cave paintings
and petroglyphs show. So did music. But each of
these art form s got an enormous boost from the
advent of civilization, as did writing, religion, and
politics. In societies nurtured and supported by
farmed food, all aspects of human culture flourished, including cooking. Culinary customs were
born. Traditional cooking had begun.
Flat breads, in contrast, could be cooked simply
HISTORY
Chinese food is another example of an aristocratically driven cuisine. The enormous variety of
time) :
1
CUISINIER
FRANCOIS
ENSEGNANT [. .A llfANfERE
de bien apprend ,e & aff,iforner lcs
Vtandrs qui fe fervent aux quatre
faifons de l'a nu e~, en Ia Table des
Gra!lds & des particuliers.
LA MANlE"R..,E PE FA17(B
/e 71oWI!on J-" OIIr l.s "ourrittlre d~ :oFHI~J
corps,foit tk.,porag~, ~n:r;e oA :ntre-r.:etJ
HISTORY
:I
I;
until done." The book included sections on meats, vegetables, legumes, fowl. and seafood . Tlw meat chapter offered
recipes for domestic livestock as well as venison, boar, and
10
1
THE HISTORY OF
Laser
Laser, a seasoning used in ancient Greece
and Rome, was one ofthe first "it" ingredients. Extracted from silphion, one of the
wild giant fen nels known as silphium,
laser was a resinous juice used extensively in ancient Mediterranean cuisines,
primarily in sauces. References to the
ingredient were peppered throughout the
first Roman cookbook, Apicius (see previous
page). People also ate silphium stalks, roots, and
leaves, whose flavor may have been similar to that of
parsley or celery. Farmers were supposedly unsuccessful in
their attempts to grow silphium, so it became a rare and
expensive commodity-literally worth its weight in silver.
Why was the seasoning so sought after? In addition to
being a versatile culinary ingredient, laser was used for
medicinal purposes (primarily as a digestive aid) and possibly as a contraceptive. Some scholars believe that its birth-
who compiled this book wrote for other professional chefs, and he described a rich and varied
cuisine. Many of the recipes call for imported
spices and show considerable sophistication.
But from a culinary perspective, Roman is not
the same as Italian. Virtually none of the dishes
mentioned in Apicius are recognizable as the
Italian cooking we know today.
One of the key Roman condiments and seasonings was garum, a fermented fish sauce similar to
Asian fish sauce and thought to be a very early
predecessor ofWorcestershire sauce (see page
5121). The Romans added their fish sauce to
everything, including desserts, but it doesn't
appear in today's Italian recipes at all.
The Romans also used lovage extensively, along
with cumin and coriander. These flavors are rarely
HISTORY
11
extinct.
Europe.
today.
different.
12
1
chefs. Consider this passage about Demetrius of
Phalerum, a diplomat who governed Athens in the
early 4th century B.c.: "He bought Moschion, the
most skillful of all the cooks and confectioners of
that age. And he had such vast quantities of food
prepared for him every day, that, as he gave
Moschion what was left each day, he (Moschion)
in two years purchased three detached houses in
the city." That's the kind of success any chef
today would like to have. It's made all the more
poignant by the word "bought"; Moschion, like
many cooks of his era, was a slave. Unfortunately,
the recipes of Moschion, the legally protected
dishes of Sybaris, and even the bad black broth of
Sparta have all vanished.
That is a sad fact of culinary history. One of the
great losses to human culture is that the food of
many empires did not survive. Homer records
many feasts in the Iliad and Odyssey, but frustratinglywithout recipes. Egyptian cooks in the
pharaohs' courts did not record their recipes. Yet
Egypt invented foie gras! What other delicacies
HISTORY
13
Roman cuisine.
14
1
not about faithfully preserving authentic tradi-
a country's cuisine.
worldwide.
traditional foods .
HISTORY
15
Visual art is perhaps the best example. Throughout the history ofWestern art, movements or
schools have set the criteria that defined the look of
a physician today?
16
True Revolution
concept.
Impressionism was the subject of public ridi-
VOLUME 1
1
newspaper essay by an art critic, who based the
name on Monet's painting Impression, Sunrise.
The critic's goal was to ridicule the movement, but
the young artists accepted the name and moved
forward undaunted. Ultimately, the Impressionists won. Public perception changed, and what was
previously considered ugly or unfinished came to
be viewed as beautiful and artistic.
Today, Impressionism is probably the most
popular artistic style. People who like modern art
regard the Impressionists as the progenitors of the
modern movement. And those with more classical
tastes still find the paintings beautiful. Impressionism is the ideal crossover genre, beloved by
people who still feel a lingering desire for representational and realistic art as well as by those who
buy into a more abstract agenda.
The greatest legacy of the Impressionists is that
they were among the first to establish the model of
artists rebelling against the system. Following the
Impressionists, one wave after another of artists
launched new movements or schools: Cubism,
century, but broadly similar trends were happening in architecture, literature, music, and other
HISTORY
17
and Frank Lloyd Wright changed the way buildings were designed. New technologies had their
way, the avant-garde was a key element of Modernism, a theme explored by Renate Poggioli in his
Interestingly, virtually all of the cultural revolutionaries who launched these movements ate very
THE HISTORY OF
18
-Madame ~
1
ernism, which brought so much change to so many
Fran~aise,
style. As one writer put it, the vitriolic criticism aimed at the
Impressionists was perhaps "the clumsy, somewhat primitive
expression of a profound bewilderment." At an exhibition in
1877, Impressionist painters met with some praise as well as
criticism, and they began to find collectors and dealers (most
of them friends of the artists) who wanted to buy their work.
These supporters proselytized for theirfriends, sometimes
drawing mockery themselves from the hostile critics.
Things changed dramatically for the Impressionists around
1880. The support of art dealers such as Paul Durand-Ruel
(a dynamic, inventive dealer who championed Monet,
Renoir, Pissarro, and Sisley) and Georges Charpentier
(a book publisher who wrote columns defending Impressionist painters and hosted one-man exhibitions for Renoir,
Manet, Monet, and Sisley) helped launch Impressionism into
the mainstream art world.
Much like Impressionism, the Modernist culinary movement
was often misunderstood by the public in its early days. Avantgarde chefs, like their counterparts in painting, were lambastBIEN
FEROCE I
impreMionnilte~
HIS TORY
19
The latter part of the 20th century saw a revolution in eating unlike anything that had occurred
ruling elite.
DANONE
20
1
Salonica, Greece, where his family settled after
being cast out of Spain in the 15th century. In
1916, the family returned to Spain and started the
Groupe Danone yogurt factory in Barcelona.
Fleeing Nazi fascism, they moved to New York and
changed the name of their company to the more
American-sounding Dannon.
At the time, Americans were unfamiliar with
yogurt, and initially the company operated at
a loss. Then, in 1947, Dannon's owners made a concession to the American taste for sweet flavors by
adding strawberry jam to their recipe. "Fruit on
the bottom" yogurt was born, and sales grew
tremendously as Americans started to embrace
the seemingly strange and exotic new product.
In the early 1920s,Jay Catherwood Hormel was
creating a new market of his own. Hormel, an
alumnus of Princeton University and a veteran of
World War I, returned from the war to work in his
father's meatpacking business. He developed
a number of innovative new packaged meat
products, starting with America's first canned
ham. Then, to use the scraps left over after the
hams were trimmed, he introduced Spam, a
processed meat product that has been famousand infamous-ever since.
Ettore Boiardi came to the United States at age
16, landing at Ellis Island. He worked his way up in
the kitchen of the Plaza Hotel in New York City,
starting as a dishwasher and eventually rising to the
position of head chef. He then moved to Cleveland,
Ohio, and opened his own restaurant, II Giardino
d'Italia. It was successful-so much so that he was
barraged with requests for his pasta sauces.
In 1928, he opened a factory to produce
HISTORY
21
22
1
McDonald's hamburgers. Fast foods may have
-""
Slow Food
HIS TORY
23
their products.
24
1
THE INVENTION OF
Plated Dishes
Go to any fine restaurant in the
world, and at least part of your
meal will most likely arrive as an
attractive arrangement of several
kinds offood on a single platewhat chefs call a "plated dish ."
This approach is such a common
method of presentation, and food
pairings are now such a focus of
haute cuisine, that one might
assume that restaurants have
always served food this way. In fact,
the plated dish is a relatively recent
innovation.
In the classic cuisine formalized
by Escoffier (see Early French
Gastronomy, page 9), food was
broughtto the table on serving
platters and dished onto plates
there, either by the diner (in causal
settings) or by the waiter or maitre
HISTORY
25
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Julia Child's book brought French cuisine
to the United States. It both led to a shift
in American home cooking and paved the
way for French restaurants in the U.S. Her
love of French food was traditional: she
disliked Nouvelle cuisine and spoke out
against it.
dish-which, in many cases, was a copy ofTroisgros's famous salmon in sorrel sauce (see The First
By 1997, only 6% had none, and 70% were predominantly Nouvelle cuisine (with two or more
overpowering authority, but rather by the opinionated modesty of an exponent of the maieutic
art: In place of the cook as mercenary of the
kitchen stove, we now have the Socratic cook,
midwife at the birth of culinary truth."
In the United States, one of Nouvelle cuisine's
chief critics was celebrity chefJulia Child, author
of the best-selling Mastering the Art of French
26
In the United States, the leading restaurant guide is the Zagat Survey. Unlike the
Michelin guide or Gault Millau, Zagat's
results are based on voting by the public.
Many consumers view the guide as being
far more accurate and reliable than the
others.
HISTORY
27
tic ways.
THE HISTORY OF
28
1
thing to the Nouvelle movement, but it never
constituted a revolution.
Today, many of the original leaders of the
Nouvelle cuisine movement are retired from
Asian cuisines.
Japanese ingredients.
HIS TORY
29
30
of the establishments at the high end are showcasing their own take on New International. This
likely to see.
The best chef cooking in the New Interna-
1
l'Atelier de Joel Robuchon is a chain of
eight identical restaurants in cites around
the world.
named restaurants-L'Atelier de Joel Robuchonmaster and chef of the 20th century came back to
the 21st century.
The fundamental reason for this expansion is
the same one that drove the fast-food revolution:
customers like to have familiar names and brands
1998, he succeeded in becoming the first "sixstar" chef since the 1930s, and many other chefs
HISTORY
31
Hans and Marketta Schilling, named the establishSpanish). Within a few years, the miniature-golf
course was retooled as a modest seaside bar and
grill serving French food, with a French expatriate
chef from Alsace. Despite its remote location, the
restaurant was ambitious. It was awarded its first
cuisine, we can point to various precursor movements. Starting in the mid-1980s, a number of
culinary trends were set in motion that would
ultimately lead to what we call the Modernist
revolution in cuisine-a change in the techniques,
aesthetics, and intellectual underpinnings of
gastronomy. This revolution is a central theme of
this book.
We do not claim that our account here is the
only way to make sense of the history of the
Modernist revolution. We focus on four major
precursors to the revolution, but it goes without
saying that some readers will have different
accounts, versions, and analyses. Nevertheless,
exploring these four developments provides
a glimpse into the early days of the new cuisine
and the factors that shaped it.
HISTORY
33
the Schillings.
34
A Focus on Innovation
Next to go was the dessert trolley, which disappeared in 1992. At the time, a dessert trolley was
HI STORY
35
36
certain techniques.
1
Dining as Dialogue
Along the way, Adria developed perhaps his most
important piece of culinary philosophy: the idea
that dining is a dialogue between the chef and the
diner. In haute cuisine up to that point, the vocabulary of that dialogue was constrained by tradition
traditional silverware?
creativity on developing a small number of signature dishes that marked their careers. Usually
nizes it.
two decades.
HISTORY
37
THE EXPERIENCE OF
38
1
Eventually, word spread to the rest of the world
that something extraordinary was occurring in
ing the people who have helped him along the way.
I calmly laid my spoon down on the edge of the bowl after one
bite-astonished .
with precision . Everything was new and strange to me: the way
the team was organized, the techniques being used, the sights,
a liquid coconut filling when you closed your mouth; tea that
came in the form of a mound of bubbles, immediately dissolv-
ing on the palate; braised rabbit with hot apple gelatin .... Wait,
how is this possible? Gelatin can 't be hot!
The meal went on in this fashion, for 40 courses and five and
half hours.
Still, I walked into the eiBulli kitchen the next day expecting
some familiarity. A kitchen is a kitchen, right?
I was ushered into a small prep room with seven other cooks,
one of whom was Rene Redzepi of the now famous restaurant
Noma, in Copenhagen. He was my ears and voice during the
Chefs were coming from all over the world to learn this
new style of cooking, yet it did not feel like cooking at all.
HISTORY
39
least 80 oc
boiled for an additional3-10 min, then refrigerated. At service time, the bags were reheated, and
restaurant.
40
1
is continually repeated in sous vide cooking.
Toward the end of the 1970s, sous vide technology crossed the English Channel to London,
where the French chef Albert Roux began a collaboration with Groen and Cryovac to promote the
new cooking method. In 1983, Roux opened a
factory in southwestern France to supply low-cost
meals made sous vide to the French national
railway system (SNCF) and to British Airways.
By the late 1980s, Roux brought sous vide to the
restaurant industry in Britain as part of an early
quick-service restaurant chain called Rouxl
Britannia. The concept was simple: high-quality
food could be economically prepared at the Home
Rouxl central kitchen by skilled cooks using sous
vide technology. The refrigerated meals would
then be distributed to restaurant outlets around
England, where they would simply be reheated
and plated by less-skilled cooks.
Unfortunately, for myriad reasons, Rouxl
Britannia eventually failed in the early 1990s. The
most frequently cited issue was that the public
Troisgros, and it also led to a collaboration between Pralus and Cryovac. Ultimately, multilayer,
heat-resistant plastic bags were produced to retain
substantial vapors and juices during cooking.
weight loss from the juices and fat that ran out
HISTORY
41
ON
FOOD
AND
COOKING
BIOGRAPHY OF
Georges Pralus
The French chef Georges Pralus is
often credited as the father of
so us vide cuisine in France,
although he shares that title with
his compatriot Bruno Goussault
(see next page). In 1974, Pralus
was enlisted by three-star chef
Pierre Troisgros to help develop
a new way to cook terrine defoie
gras that would prevent the 30-50% weight loss that
occurred when traditional cooking techniques were used .
Pralus came up with the idea of wrapping the foie gras in
several sheets of heat-resistant plastic before cooking.
After some experimentation, he found a wrapping method
42
that limited the weight loss to just 5%. Later, he began using
vacuum-sealed plastic bags instead .
Some chefs were skeptical that food cooked in plastic
would taste as good as traditionally cooked food. But the
influential French chef joel Robuchon quickly recognized the
potential of this new technique and endorsed Pralus. Thanks
in part to Robuchon's support, Pralus and the Sealed Air
Corporation, the manufacturer of Cryovac packaging,
opened a school in 1979 to teach so us vide techniques, and
they worked with Goussault to develop and disseminate this
Modernist method of cooking (see page 2192). Pralus taught
the technique to some ofthe top French chefs, including Paul
Bocuse, Alain Ducasse, and Michel Bras. Today, Pralus continues to teach chefs and culinary students around the world.
BIOGRAPHY OF
Harold McGee
Harold McGee is one of the leaders of the
movement to inform chefs about the
BIOGRAPHY OF
Bruno Goussault
Though not a chef, Bruno Goussault has become
one of the most influential proponents of so us
Pralus was experimenting with so us vide cooking in Pierre Troisgros's kitchen (see previous
page). In 1979, Pralus and the Cryovac company
In 1981, Cryovac hired Goussaultto help systematize the curriculum at its so us vide school.
Goussault is generally credited with promoting, in the early 1970s, that cooking so us vide at
temperatures well below boiling could improve
Soon after that, Goussault worked with Robuchon to create a menu for the first-class cars of
the French national railway system (see page
2192). In 1991, Goussault launched his own consulting company, the Centre de Recherche et d'Etudes pour
cooked so us vide.
HISTORY
43
calls the book "a must for every cook who possesses
Jill
fornia there.
In December 1988, she attended a conference at
l t l , I I \ 0 \11\SYOJ
pll\ 'it .rl g.htrono my. " Sonw time later, Kurti phoned An-
morp to the point , who should gl'l credit for what. Hervt; This
rpvitwed a draft of this chapter, and he told us it was incorrpcl. HP reiterated his vtrsion of evtnts, but dPclined to
his story, but hP couldn 't waste time digging them out.
plim. llw
VVhich story is corrpct? VVP don 't know, lwcauw Wl' werl'
44
'l
\\l'
1
I: I I II , 1; I I' II \
II
over the next 12 years. After Kurti's death in19<JB, Hervl; This
named the next meeting of the Ericl' workshop in his honor:
HISTORY
45
molecular gastronomy.
BIOGRAPHY OF
Herve This
Herve This was an editor of Pourla Science, the French
edition of Scientific American magazine, from 1980 to
2000. His interest in food led him to collaborate with
Nicolas Kurti, Harold McGee, and Elizabeth Cawdry
Thomas to create the first International Workshop on
Molecular and Physical Gastronomy in Erice, Sicily
(see previous page).
This is a prolific author and has written or coauthored
many books, including Kitchen Mysteries (2007); Cooking:
46
1
II II
'll
The discipline that Herve This !Prnwd "molecular gastronomy " has had a slight shift in goals over the years. This says
"the initial program of the discipline was mistakenly mixing
science and technology."' But he says he has corrl'Ctl'd that
mistake and nmoved technology from the definition. In
a 2009 review article and subsequlnt personal communications with us, This dPscribes molecular gastronomy as
This divides till' "rww program " for molecular gastronomy into four primary component<.:
I. Model "culinary definitions."
HISTORY
47
I Ill
I l l ' I I J 1\\
III
48
VOLUM E 1
1
public. That's because food science was mostly
funded by industry or by government agriculture
departments that wanted to boost the agricultural
economy on a large scale. Most of the findings
ascribed to molecular gastronomy were discovered in the course of those activities.
There are also many issues that food science has
simply not investigated, because they are not
important to large-scale food manufacturers.
Nicholas Kurti is famous for saying, "It is a sad
reflection on our civilization that, while we can
and do measure the temperature in the atmosphere ofVenus, we do not know what goes on
inside our souffles." Nobody in industry cared
much about souffles; you couldn't make them in
bulk to put on supermarket shelves. And if nobody
in industry cared, food scientists tended not to
investigate. It's not like the U.S. Department of
Agriculture or the National Science Foundation,
both major funders of academic research, care
much about souffles either.
Starting in the mid-1980s, the situation changed
dramatically, as McGee, This, Barham, and others
shined the light of science on problems of home and
restaurant cooking. The main distinguishing
feature of molecular gastronomy is that it does care
afford it, he traveled to France on culinary research missions. In 1986, he read Harold McGee's
HISTORY
49
much to claim that the approach that [Blumenthal] is taking represents the biggest shake-up to
week stage in Blanc's kitchen. It was a rude awakening, a sort of baptism by fire. Blumenthal rose to
usual.
50
1
that knowledge, create an experience that
substance.
Another theme that runs through much of
Blumenthal's cuisine is the role of memory and
nostalgia. He tries to re-create tastes and aromas
that will trigger childhood memories and evoke
emotions. Unlike deconstructionist chefs,
Blumenthal does not aim to provoke a double
take as the diner recognizes the classic dish
being referenced. Instead, he wants to evoke just
the present.
centuries of tradition; pair that with evolving knowledge and the overall effect of
an feasts.
struction, but with a twist all their own. In deconstruction, the flavor profile is that of
HISTORY
51
have it, his first night there coincided with the visit
52
(i)
Modernist dishes take on many forms, reflecting the diversity of culinary visions at work
among their creators. The appearance of the dish is often an integral part of the dialog
between chef and customer. Surprise, drama, humor, and even misdirection are part of
what makes Modernist cooking so unique-both to make and to eat.
Grant Achatz, Alinea: Salsify, Smoked Steelhead Roe, Parsley Root, Radish
(photo by Lara Kastner/Aiinea)
Ferran Adria, eiBulli: Hot Cauliflower and Lobster Jelly with Caviar; Olive Oil
Spring; Consomme Tagliatelle Carbonara; @ Fried Rabbit Ears; @ Carrot Air with
Mandarin and Bitter Coconut Milk; @ Cepes in Amber; @ Frozen Foie Gras Powder
with Foie Gras Consomme;@ Melon with Ham 2005; @ Red Mullet Mummy with Sea
Water Cotton Candy; @ Cherries in Ham Fat Cream; @ Pumpkin Seed Oil Candy
(photos by Francese Guillamet)
Andoni Luis Aduriz, Mugaritz: CD Vegetable Coals with Scrambled Eggs and Crushed
Potatos; 0 Buttery ldiazabal Cheese Gnocchi with Ham Broth; Potato Stones
(photos by Jose Luis L6pez de Zubiria-Mugaritz)
Heston Blumenthal, The Fat Duck: @ Nitro Scrambled Egg and Bacon Ice Cream with
Pain Perdu; @ Snail Porridge (photos by Dominic Davies)
54
Wylie Dufresne, wd-50: 0 Eggs Benedict; @ Foie Gras, Passionfruit, Chinese Celery;
@ Aerated Foie Gras, Pickled Beet, Mashed Plum, Brioche (photos by Takahiko Marumoto)
Quique Dacosta: @ Stevia Sponge (photo by Carlos Rond6n, www.carlosrondon.es)
21
HISTORY
55
deconstruction.
THE PRINCIPLES OF
Modernist Cuisine
Modernist cuisine is still young and evolving. Its direction
has been determined by the vision of individual chefs,
rather than by committee or consensus. Still, looking at the
movement today, it is possible to discern some shared
general principles. In much the same way that the Gault
Millau guide outlined the "10 commandments" of Nouvelle cuisine (see page 27), here we offer 10 principles of
the Modernist movement.
1. Cuisine is a creative art in which the chef and diner are in
dialogue. Food is the primary medium for this dialogue,
but all sensory aspects of the dining experience contribute to it.
2. Culinary rules, conventions, and traditions must be
understood, but they should not be allowed to hinder
the development of creative new dishes.
3. Creatively breaking culinary rules and traditions is
a powerful way to engage diners and make them think
about the dining experience.
4. Diners have expectations-some explicit, some implicitof what sort offood is possible. Surprising them with
food that defies their expectations is another way to
engage them intellectually. This includes putting familiar
flavors in unfamiliarforms or the converse.
56
1
~
ii
ing,!tToccs Contcmporcincos (Contemporary Rices), published in 2005 by ,\ 1ontagud Editores, in which he demonstrated his approach to the regional staple. Dacosta
on classical Andalusian cuisine, including dishes likl' gazpachos andfrituras. Lih Roc a , Garua sees mlmory as om of
the most important aspl'Cts of his culinary philosophy. He
received a Michelin star in 2007.
Dacost.J , like Adria , is a self-taught chef. At his restaurant
in Denia on the coast near Valencia, Dacosta has madl' his
name with his Modernist treatnwnts of local produce and
decades, both art and architecture have experienced a reaction to the century-long domination
of Modernist movements.
HISTORY
57
chefs will not serve any dish they did not invent or
develop (at least in part). They also bristle if other
edgment or credit.
style, focus on both design and execution. Customers expect that the chef will have her own inven-
serve a baked potato with it because the steakhouse chef didn't invent the baked potato. In
traditional cuisine, there is often an implicit
A steak house is perhaps the most extreme example: the product, a steak, isn't unique to the chef or
BIOGRAPHY OF
Joan Roca
One of the leading figures in
modern Spanish cuisine, chef
joan Roca is known for his
innovative take on traditional
Catalan fare. Roca was
steeped in that style of cooking from an early age, spending many hours in the kitchen
with his mother and grandmother at his family's Restaurant de Can Roca in Girona,
two brothers, josep and
his
Catalonia. In 1986, Roca and
jordi, opened their own restaurant next door to their
parents' place, with joan running the kitchen, josep as
sommelier, and jordi as pastry chef.
At El Celler de Can Roca, today a three-Michelin -star
58
establishment, joan Roca soon began applying new techniques and technologies to classic Catalan cuisine. His philosophy is to use technology in the service of creativity to convey
emotions. Over the years, he has worked with so us vide,
vapor cooking, smoking, distilling, and various othertechniques. One of his most famous achievements was figuring
out a method for distilling soil from a nearby forest to create
a "dirt essence." He made a clear jelly from the liquid and put
it on top of an oyster-a unique rendition of surf and turf.
Roca's 2005 book, Sous Vide Cuisine, cowritten with Salvador Brugues and published by Montagud Editores, was the
first major cooking text to describe how to use this technique.
The authors outlined a new system that would allow chefs to
cook sous vide dishes to order during a restaurant's regular
service. Despite being hard to find in the U.S., the book
became a valuable resource for food professionals.
,.
1
I:
II
II ,
1; I
I' I I I
ll
food journalists that spotlights till' work of culinary innovators and stars of tlw Modernist movement.
Santos is the founder and director of Spain's other prestigious international gastronomic conference, Lo mejor de Ia
gastronomia, which also highlights Modernist cuisine and
has included workshops with Adri<1, Rene Redzepi (see page
70), Quique Dacosta (see page 57), and many more. Santos
has also written extensively about Spanish Modernist chefs
in his annual guidebook (whose inaugurall995 edition gave
top honors to eiBulli) and in El Corrco.
The Internet has also stoked the fires of Modernist innovation. When a new dish goes on the
menu anywhere in the world, the chances are very
high that it will be the subject of postings on
eGullet.org, Chowhound.com, or Twitter, complete with digital photos and detailed explana-
related blogs.
Meanwhile, information about new techniques
HISTORY
59
on hand in hospitals.
might seem.
in cuisine. It might seem like a very straightforward thing to find out who first used this cryogen
kow, Poland.
ice cream.
This technique was so successful that he started
60
1
Daguin was starting to experiment with liquid
nitrogen. Daguin was the founding chef at the
restaurant Jardin des Saveurs at the Hotel de
France in the small country town of Auch in
southwestern France. At the time, Daguin's
restaurant held two Michelin stars and was
a leading example of the regional cuisine of
Gascony. Around 1976, the chef visited a facility
in nearby Aubiet that did artificial insemination
of cattle. Part of the tour included a demonstration
ofliquid nitrogen, which was used to keep bull
semen in cold storage. This visit inspired Daguin
to try using liquid nitrogen in the kitchen.
He made a number of novel ice creams and
sorbets and served them at his restaurant, where
he mixed liquid nitrogen into the ice cream base
tableside with great drama, just as Marshall had
suggested. Daguin also prepared liquid nitrogencooled dishes at dinners around the world, including a banquet for the prestigious international
Princeton.
In 1987, Curt Jones, a biologist who was familiar with liquid nitrogen in scientific applications,
discovered a method for creating miniature frozen
process.
HISTORY
61
temperature physics, had never heard ofliquidnitrogen ice cream before seeing Barham's demon-
THE HISTORY OF
62
1
in history to sell liquid-nitrogen ice cream made-
Meanwhile, in the U.S., several parallel developments were taking place. In 2002, Rob Kennedy, of the tiny town of Rock Island in Washington's Cascade Mountains, began making liquid
stays truest to Marshall's original vision of madeto-order single servings of ice cream.
In 2003, Theodore Gray, a computer scientist
and cocreator of the Mathematica scientific
HISTORY
63
THE HISTORY OF
64
culinary applications ofliquid nitrogen. In retrospect, her idea was a brilliant mental exercise, but
in the kitchen.
HIS TORY
65
THE HISTORY OF
Ideas in Food
In late 2004, while working at Keyah Grande, a remote
hunting lodge in Colorado, chefs H. Alexander Talbot and
Aki Kamozawa launched their food blog, Ideas in Food
(ldeaslnFood.com), to chronicle their explorations in Modernist cuisine. The lodge was an inauspicious place to
launch anything. It was deep in the wilderness, miles from
the nearest town. It had only eight rooms, which were
mostly used by elk hunters who viewed dinner as a time to
refuel rather than as a gastronomic adventure. These guests
were more often looking for familiar comfort food than
spectacular Modernist cuisine. Many of them were shocked
to sit down to a table, often in camouflage gear, only to be
served dishes like smoked trout roe over parsnip ice cream .
Nevertheless, Talbot and Kamozawa were committed to
Modernist food, and they saw their blog as a way to communicate with kindred spirits across the globe. They used the
website to catalog their experiments in the kitchen and took
turns jotting down their thoughts in this new online notebook.
The premise was simple, but the subject matter was radi-
66
cal: Talbot and Kamozawa wrote about working with ingredients like methylcellulose, transglutaminase, and liquid
nitrogen, and with equipment like dehydrators and Pacojets.
The pair also openly discussed recipes and techniques that
would have been trade secrets in many restaurants.
Alongside the main blog entries, they published PDF files
with additional notes about current and future projects. No
one had done this before- at least not in a way that emphasized the ideas that undergird Modernist cooking as much as
the novel techniques. Ideas in Food quickly developed a cult
following among Modernist chefs, both amateur and professional. The power of the Internet to connect people let
Talbot and Kamozawa reach an audience that they never
could have otherwise. Today, in addition to maintaining the
blog, the team runs Ideas in Food, LLC, a consulting business
based in Levittown, Pennsylvania. They also wrote a column
called "Kitchen Alchemy" for the Popular Science web site.
Their cookbook, Ideas in Food: Great Recipes and Why They
Work, was published in 2010.
HISTORY
67
68
HISTORY
69
IHI HISIORY OJ
70
VOL UM E 1
1
similar ideas with different words does not, as
copyright-it is designed to protect the fundamental idea rather than the exact instantiation. Patents
THE HISTORY OF
HISTORY
71
What Next?
72
1
New schools and movements will emerge, with
proiessional chds Imam oil\ hom use the sitel and ama-
plastic bags that hung in the\\ ater irom clips at the top. This
technique kept the open end oi the bag out oi thl' 1\ atl'r. The
HISTORY
73
74
Caramelized Pork Scratchings; @ Spherical Green Olives; @ Frozen Parmesan Air with
Muesli (photos by Francese Guillamet) Pea Sphere (photo by Nathan Myhrvold)
Andoni Luis Aduriz, Mugaritz: Sun Ripened Red Fruit with Beet Bubbles (photo by
Jose Luis L6pez de Zubiria-Mugaritz)
Heston Blumenthal, The Fat Duck: @ Nitro Green Tea Sour (photo by Dominic Davies)
Homaro Cantu, moto: Edible Menu
Quique Dacosta: @ Sprouts 2000 (photo by Carlos Rond6n, www.carlosrondon.es)
Wylie Dufresne, wd-50: 0 Miso Soup with Instant Tofu Noodles (photo by Takahiko
Marumoto)
HISTORY
75
architecture emerged.
THE HISTORY OF
Trade Secrets
In addition to trademarks, copyrights, and patents, there is
a fourth branch of intellectual property law: trade secrets.
A trade secret is a method, recipe, or approach that is hidden from public view. In that sense, it is very different from
patents, copyrights, or trademarks, which are registered
with the government and thereby disclosed to the public.
It is up to the owner to keep a trade secret. If someone else
does her own research and re-creates the secret recipe or
technique, she has every legal right to use it. The only protection provided by the law is a prohibition against outright
theft oft he secret.
Colonel Sanders's recipe for fried-chicken batter, which
famously contains "a blend of11 herbs and spices," is a trade
secret, as is the recipe for Coca-Cola. Like many companies,
KFC a nd Coca-Cola opted to use trade secrets instead of
pate nts because trade secrets are forever, whereas patents
typically last for about 20 years before becoming part of the
public domain.
Coca-Co la has maintained the secrecy of its soft-drink
formula for more than 100 years, at least in principle. Of
course, the reality is that the formula has changed over the
years: high-fructose corn syrup has replaced sugar, and there
have been many adj ustments to the other ingredients.
Another advantage of trade secrets is that they apply to
things that wou ld not be eligible for patent or copyright
protection. Mos t recipes fall into that category.
Critics point out that many companies use their "secret"
formula primarily as marketing hype. Although they do keep
the formula secret, it is unlikely that disclosing that formula
would dramatically change the company's sales. This is
76
1
are quite mundane; warehouses, office buildings,
shopping malls, and homes all need to exist for
very prosaic reasons. Yet architecture can also be
Further Reading
HISTORY
77
to the recipe or procedure are also given, in brackets. The list also
book. For each recipe, the initials of the inspirational chef or inven-
tor are given (see the key below), as well as a general indication of the
book.
2000
1995
1970
AA
AD
Andre Daguin
AK,AT
1974
GP: sous vide foie gras terrine [3176]
AM
Ambrose McGiuckian
cc
Carlo Cracco
1976
DA
Dave Arnold
DC
David Chang
1996
DK
David Kinch
DP
Daniel Patterson
Early1980s
FA
Ferran Adria
GA
Grant Achatz
GP
Georges Pralus
HB
Heston Blumenthal
1987
1997
HC
Homaro Cantu
HT
Herve This
JA
Jose Andres
JC
Jordi Cruz
1988
JFP
Jean-Fran~ois
JGV
Jean-Georges Vongerichten
Jl
Johhny luzzini
1989
JMA
JR
Joan Roca
MB
MC
Michel Bras
1990
ML
MSR
Piege
NN
Nils Noren
1998
2001
HB:gellan
[2-406]
1992
FA: cold jelly as a sauce [4140]. herb jus,
nut milk [459]. service on a spoon
Rational AG
1993
58
Sean Brock
SHD
Sang-Hoon Degeimbre
TK
Thomas Keller
WD
Wylie Dufresne
WM
Wilhelm Maurere
ws
Winston Shelton
78
2002
Nathan Myhrvold
Quique Dacosta
Marc Veyrat
QD
RA
NM
Paul Liebrandt
[4 140]
MV
PL
1991
Pascal Barbot
Michel Troisgros
Pierre Gagnaire
1999
MT
PB
PG
Name of recipe
or procedure
Volume and
page number
Topic
Initials of the chef
or inventor
1994
FA: clear vegetable juice [2-350]. ham
consomme [448]. herb water [2310].
liquid ravioli
Topic
Volume and
page number
2003
HB: Activa, Mackerel invertebrate
[J250]
Oyster with Mignonette Foam [4265]
FA: airs as sauces, soy lecithin
2005
2006
NM: cold plunge does not stop cooking
[2-254]
2004
FA: centrifuge [2-362]. teppan-nitro
(liquid nitrogen plancha) [J124]
Lemon egg yolk fluid gel [4180]
HI STORY
79
[2-444]
2007
2008
Edamame Sheets, King Crab,
Cinnamon Dashi [4118] WD: Activa
RM pasta
Goat Cheese Dumpling [4119]
AK, AT: Activa YG dumpling
2009
- - - - - -- - -
80
1
Parmesan Polenta [4181]
NN, DA: coarse gellan fluid gel
2010
Chawanmushi [496] MC: Activa
DC: bacon katsuobushi
HI STORY
81
1
THE STORY OF THIS BOOI<
Browse any bookstore, online or brick-and-mortar,
elucidating aspects of each chef's personal culinary style. Chefs don't usually aspire to write
That level of effort is the norm for a major reference work or college textbook. Resources on this
scale are generally not available to independent
food writers, however.
Of course,Julia Child is one notable exception
to this rule, but she had two coauthors, and even
then, they undertook an arduous nine-year
journey to the publication of Mastering the Art of
of book worked in 1961, but it wouldn't be competitive in today's market, where numerous visual
HISTORY
63
84
1
might have treated that as three distinct projects,
but to me they seem to hang together as a unit.
This account of the book's history has been
proceeded to do.
techniques that involve purely traditional ingredients. Want to make perfect omelets for a crowd?
HISTORY
85
ing executives tell chefs they have to compromise, and the chefs believe them. That's because
86
1
is that the material is too complicated for readers
for the love of it. Anyone who loves food will find
HISTORY
87
The Photographs
There are about 3,700 color
photographs in the book. We took
over140,000 ofo urown shots to
generate these. We also used
photography from other sources.
more visual.
That's tricky, because some important foodscience concepts are not easy to visualize. A key
88
cut apart.
1
cutaway-for example, the whipping siphon
through the air: film them "flying" while supported by wires, then digitally remove the wires.
technically not a pure photo, nor can it be. Nevertheless, the cutaway photos are as close to real as
many chefs can't tell you why a common foodexplain the differences between viral, bacterial,
and parasitic infections. Chapter 2 de mystifies
these things.
HISTORY
69
also found that government food-safety regulations take positions that are based as much on
politics and lobbying as on science.
90
VO LU ME 1
1
understood. Chapter 9 on Sous Vide Cooking
covers that invaluable technique in detail.
much more.
HI STORY
91
1
ABOUT THE RECIPES
Modernist Cuisine, both the culinary movement
recipes in such a way that you can better understand not just the what (ingredients) and the how
(methods), but also the why. To accomplish this,
we needed a new format for presenting recipes.
The compact, modular form of our recipes
limited to cutting-edge dishes-we cover everything from American regional barbecue to innovative flavored gels. The point is not to tout modern
Recipes here use a number of unusual ingredients, like xanthan gum, sodium alginate, gellan,
In part, that is because the specialized ingredients used in this form of cuisine can be quite
powerful. A little too much of a gelling agent, for
HISTORY
93
who make their own whiskey. At the other extreme, Oregon has a state-funded program dedi-
its volume, unless the quantity needed is undefined. Salt is usually relegated to the vague notion
of "to taste," but where practical, we provide
measurements for salt by weight. Obviously, if you
like more or less salt, adding it to taste is always
your prerogative, but we believe it's important to
maintain as much precision as possible so that you
achieve the same textures and flavors that we did
when developing these recipes.
Ingredients that come in distinct units, such as
eggs or allspice berries, are an exception to this rule.
We usually still measure these by weight, but we also
list the rough equivalent units for reference. And
94
1
cooking stores around the world. They're common
expensive investment. If you've measured ingredients only by the cup and teaspoon until now, this is
a great time to buy a good scale and begin applying
Baker's Percentage
ing temperatures. Typically, the higher the temperatures, the less critical it is that they be precise.
But when you're cooking salmon mi-cuit
(literally "partially cooked"), the color of the flesh
to no more than 40 c
HIS TORY
95
QUANTITY
100g
SOg
35 g
Egg yolks
100%
Stock or water
75g
(four large)
20g
225g
4g
1g
four eggs
PROCEDURE
(!) Combine.
0 Reduce to syrup-like consistency.
Strain.
@) Measure 20 g of wine reduction.
Blend thoroughly with win e reduction.
SCALING
133%
67%
47%
@)
Vacuum sea l.
27%
300%
5.3%
1.3%
you can easily work out how much egg yolk to use
original version.
The special scaling sometimes becomes crucial
96
(28%)* @
G)
1
instead use the special scaling listed for gelatin,
age would let you easily work out the right amount
a compact form.
result may not set the way the original recipe does.
be cooked at 75 oc
example recipes, parametric recipes, and plateddish recipes. Each serves a different purpose in
HISTORY
97
Parametric recipes typically contain three parts: an introduction that explains some of
the underlying principles at work (not shown in this example), steps CD that outline the
general procedure for making the recipe, and one or more tables, typically organized by
main ingredient, 0 that present the parameters-ingredients, quantities. preparation
steps, cooking times and temperatures, etc.-for making a number of variations.
Ingredients for each variation are grouped together between horizontal lines. In the
example below, the recipe for asparagus puree calls for blending both vegetable stock and
unsalted butter together with the sliced asparagus. More than one variation is sometimes
given for a main ingredient. as indicated by an indented line.
If no ingredient is listed for a variation, that indicates that we don't consider any
additional ingredient necessary in this case. A value of "n/a" indicates that the value for
that column is not applicable for a given variation.
Cooking instructions typically include both temperatures and times, given in
minutes (min) or hours (h), as indicated by the unit at the top of the column. When a time
is unusually short or long, the abbreviated unit is included with the number. @
Quantities in parametric recipe tables are often given as percentages of a liquid or
a main ingredient. 0 as indicated by a note at the bottom of the table. @ References
to related example recipes, plated-dish recipes, or step-by-step procedures are often
given in a "See page" column.
CD
Prep
Method
(oc )
peeled, quartered
sousvide
90
asparagus
thinly sliced
saute
high
heat
artichoke
apple
80
(of)
(min)
194
2 V2 h @
10
(scaling)* Tool
Liquid
176
45
vegetable stock 50 %
olive oil
5%
1h
cooked beet
juice
50%
beet
peeled, thinly
sliced
so us vide
80
broccoli
stems, peeled
and sliced
saute
medium
heat
12
neutral oil
florets, sliced
boil
high heat
neutral oil
176
See page
commercial
blender
517
commercial
blender
341
commercial
blender
commercial
blender
3%
commercial
blende r
3%
Pacojet
426
98
1
22
-------- --------
-------=======
=- -
Truth be told, the monkfish is not the most bc;~utiful fish in th, ~oa.
Olbsent from most of the Pacific, however, with just one species that
from its head a long spine with a soft fleshy end th;at twitches like a
Chefs pri1;e monkfish for the tai l meat; the texture of the meat
wonn. When a fish comes in for the bait, the monkfish distends its
enormous jaws; it can swallow fish as long as its own body. Six oft he
the real thing. Here, we cook monkfish sous vide and garnish it with
YIELD:
SPECIAL EQUIPMENT:
TIME REQUIRED:
four portions
sous 11ide equipment, whipping siphon
49 h o11erall (J 5 d if making Salted Halibut), including 1 h preparation and
30 min to reheat and finish
@ ORDER OF PREPARATION ,
TIME TO
COMPONENT
PREP
COOK
FINISH
12h'and /Sd'
Salted H alibut
optional,secpag.,JI87
5min
Pilei C b o ux
160g
750g
2d'and l h20min
Halibut Bra.ndade
Z u cchini Blossom Be ign e t.s
IOmin
IOmin
5min
640g
5min
four
3min
/Smm'
450g
20min
2min
25Qg
lOg
Sp ice M ix Emuls io n
2.5min
QUANTITY
IOOgeach)
12
"(unattended times)
ASSEMBLY,
Cook monkfish sous vide at 48 c I 11 9 'F to core temperature
Whilt.fish iswol:ing:
Deep-fry battered zucchini blossoms in 195 c I 380 ' Foil until
golden brown, about 3 min. Drain on paper towel-lint'd tray.
and green almonds, and dust with additional fish spice mix.
Po ur spice miJ: emulsion at table.
@ HALIBUT BRANDADE
@ ~quantityohhewholeml~v.oll
depend on the -SIZe oft he fish as
well as the shape and si~e of the
Yields800g
INGRED IENT
QUANT ITY
Whole mille
Salted halibut
as needed
160g
100%
25g
16%
Wolle..
Yukon Cold or ()(her W<~.xy 250g
po!Oitoes,thiolysliced
"
625%
blr;a-virgiooliveoil
90g
56%
SCALING
opci<HY~-,..... 3117
Cilrlic, slicedand
blanched twice
Good quality, store-bought salt cod
Colobesubstitutedforthehalibut
156%
PROCEDURE
HISTORY
99
100
VOLUME 1
1
have still made some adjustments to techniques or
ingredients, and we may have rearranged procedures a bit to explain things more clearly.
Ultimately, we take full responsibility for all
recipes in this book and how they turn out in your
kitchen. We've tested them all extensively, and
although we'd like to feel they are foolproof, it's
likely that some steps allow a bit more latitude than
The remaining recipes are those that we developed from scratch on our own. For example, we
creating a recipe that calls for expelling a premade souffle mixture from a whipping siphon into
Safety
Physical safety is always an important consider-
create it.
HISTORY
101
2
MICRO BIOLO GY FOR COOKS
Aside from diners at a safari camp on the
African savanna, people need not worry about
predators.
food. We offer a broad survey of the field, complete with the names and descriptions of key
rate descriptions.
microbiological hazards.
Disclaimer:
This book cannot and
does not substitute for
legal advice about food
regulations in the United
States as a whole or in any
U.S. legal jurisdiction. Nor
can we guarantee that
following the information
presented here will prevent food borne illness.
Unfortunately, the many
variables associated with
food contamination make
eliminating all risk and
preventing all infections
virtually impossible. We
cannot accept responsibility for either health or
legal problems that may
resu It from following the
advice presented here. If
you operate a commercial
establishment and serve
food to the public, consult
the rules and health
regulations in your area.
105
MICROB ES AS GERMS
microorganisms: living creatures, typically
The vast majority ofbacteria and other microscopic life forms are perfectly harmless or even
beneficial. That's lucky for us because the human
THE TECHNOLOGY OF
-..
~
106
.I
J
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.:::--
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Q
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,_
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(..
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...
.?
~-
t:?
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\'t -
....
,. "'"''.
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if
._..,._
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2
A Window into the World of Single-Celled Life
The microscope, the device that opened the microbial
universe to human observation, boasts a truly international history. One thousand years ago, pioneers in Europe
and the Middle East laid the foundations for the technology by producing simple magnifying lenses that are convex: thick in the middle and thinner toward the edge.
The firsttrue microscope dates to late 16th-century Holland, when a lens grinder there placed two lenses inside
a tube and saw that the apparatus could greatly magnify
objects in its view. The Tuscan astronomer Galileo, who
is more commonly associated with telescopes, studied
the initial crude device, then crafted a better version that
used a compound lens.
In 1665, British physicist Robert Hooke published the
first microscope-aided scientific study, Micrographia, an
illustrated book that detailed previously unseen marvels
such as the porous microstructure of cork that confers
its buoyancy. Shortly thereafter, Dutch fabric merchant
Antony van Leeuwenhoek began constructing simple
but refined single- lens microscopes . He used his instruments to describe insect parts, blood cells, sperm, parasitic worms, protists, and what he called "animalcules"tiny organisms in dental plaque that were the first
recorded observations of living bacteria.
Frequent innovations in the centuries since have produced microscopes that today enable researchers to
magnify matter at the subatomic level.
'.
A mechanica l stage holds the glass slide with the specimen ........ .
Turning the associated knob allows fine adjustments to the
portion of the slide that's in view.
A co nd enser concentrates light and shin es
it through specim e ns to revea l their details .
Specialized versions show spec imens on a
dark background.
An illuminator beams light ........... .
through the specimen
from below.
10 7
add ressing the ri sks vary in each case. Although plasm ids-infectious
strands of DNA-ca n ex ist within a range of organisms, we d iscuss them
in the co ntext of their bacteri al hosts, in which they play criti cal ro les in
causi ng disease.
This in credibl y diverse group of mostly singl ecell ed mic roorganisms includ es fungus- like,
naked eye.
Size: th ey range from microsco pi c worms a tin y
fraction of a millimeter long to tapewor ms that
ca n reac h 9 m I 30ft in ex treme cases
Associated illnesses: trichinellosis, anisa ki as is,
ascarias is, fascioliasis, "fish flu," and tae ni as is
Examples: roundworms such as Trichinella
spiro/is (above top and bottom), Anisakis simplex,
and Ascaris lumbricoides;
fluk es suc h as Fasciola hepatica and
Nanaphyetus sa/mineola;
tap eworm s such as Taenia saginata and
Taenia solium
Size: although the typical range is 0.0010.005 mm, th ese microorganisms have di ameters th at run from 200 nanom ete rs (2 00
Cyclospora cayetanensis
Cryptosporidium parvum
Entamoeba histolytica
Campylobacter j ejuni
Listeria monocytogenes
Yersinia enterocolitica
multiple Salmonella species
multiple Shigella species
Clostridium perfringens (above bottom)
Staphylococcus aureus
Bacillus cereus
108
109
FOODBORNE ILLNESS
Food borne illness almost always
takes one of three forms:
Invas ive infectio n: pathogenic
organ isms penetrate and grow in
human tissue and may secrete
tox ins. Examp les include al l
food borne protists and viruses, the
parasitic worm Trichinella spiro/is,
bacteria such as Escherichia coli
0157: H7 and Listeria manacytagenes, and the bovine spongiform
encephalopathy prion (the agent of
mad cow disease).
Noninvas ive infection: pathogens
live in the gut but do not penetrate
it and may secrete toxins there.
Examp les include the beef tapeworm Taenia saginata and bacteria
such as Vibrio cholerae and Yersinia
enterocolitica.
Food poiso ning: bacteria re lease
toxins into food before it is eaten.
Examp les include bacterial species
such as Bacillus cereus, which
secretes four different toxins, and
Clostridium botulinum, the organism
that produces the compou nd in
Botox injections that smoothes
wrink led skin.
11 0
111
THE ORIGIN OF
Scientific Names
In 1735, the great Swedish botanist Carl von Linne (better
known as Carolus Linnaeus) invented a naming system that
is still the preferred method forthe scientific classification
of living things. Under Linnaeus's system, every organism
receives a two-part scientific name. The first part, the
genus, is akin to a family's surname, whereas the second,
the species, refers to a specific representative of that clan.
A typical scientific name of a bacterium, for example, is
Escherichia coli. In this case, Escherichia denotes the genus,
and coli refers to the species. By convention, researchers
italicize the full name, capitalize the first letter ofthe genus,
and leave the species in lowercase letters. An abbreviated
scientific name consists of only the first letter of the genus,
followed by the full species name: E. coli.
The same naming convention applies to nearly all organisms, extant or extinct, which makes the king of the dinosaurs
Tyrannosaurus rex, or T. rex, and we humans Homo sapiens, or
H. sapiens. To refer to an entire genus, the abbreviation "spp."
is sometimes used: Salmonella spp. means the species within
the genus Salmonella.
Species in the same genus are close relatives: E. coli and
E. albertii, for example. But they can remain quite different,
Domain: Bacteria
Class: Gamma-proteobacterla
112
Family: Enterobacteriaceae
Family: Canidae
a.-: Escherichia
2
Foodborne diseases from viruses proved far less
severe in general, resulting in only 129 deaths
(7.1%), despite the huge number of viral cases.
And the few cases that the study ascribes to
parasitic worms did not cause any fatalities at all.
The CDC study indicates, for instance, an estimated mortality rate of three deaths per 1,000 cases of
trichinellosis, compared with 200 deaths per
routine activities.
Contamination Sources
But most viral illnesses are mild, so the picture for mortality (right) is quite different.
Protists, which cause fewer than 3% of cases, result in more than 2D% of deaths, due in
large part to the lethality of Toxoplasma gondii. And although bacteria may cause fewer
than half of food borne illnesses, they are blamed for almost 75% of fatalities; salmonellas
and listerias are the worst offenders. The only parasitic worm included in the CDC study is
Trichinella spiralis, which is so rare a pathogen as to barely show up in the statistics.
Illnesses by organism
Deaths by organism
11 3
THE DIAGNOSIS OF
CLASS OF SYMPTOMS
Gastroenteritis
Persistent diarrhea
(prim aril y vo mitin g but also poss ibl y feve r and di arrh ea)
Common culprits: rotav irus in an infant; no rov iru s o r related viruses in
adults; food poi son ing from ingeste d toxin s of Staphylococcus oureus o r
Bacillus cereus. Symp tom s ca n also indi cate heavy- metal po iso ning.
Noninflammatory diarrhea
Neurologic symptoms
(usuall y no feve r)
Common culprits: nea rl y all foo d bo rn e path oge ns, in cl uding bacteria,
proti sts, and viru ses . Noninfl amm ato ry di arrh ea is a cl ass ic symptom of
Escherichia coli tox in in th e small in tes tin e.
Inflammatory diarrhea
General malaise
(wea kn ess, headaches, mu scl e and j o int pain, fever, j aundi ce)
Common culprits: bacteria such as Listeria m onocytogenes, Salmonella
typhi, and Brucella spp .; wo rms, in cl udin g Trichinella spiro/is; vi ru ses such
as hepatitis A; pro tists, including Toxoplasma gondii.
intes tin e.
11 4
2
or their eggs, which are otherwise known as
of other humans.
2. Do not consume the feces, vomit, or spittle
of animals.
isms a gram.
To discern why this is true, it helps to understand a few technical concepts. In most cases, just
A Dose of Pathogen-Related
Terms
LD 50 : t he nu mbe r of pathoge ns p er
indiv idual t hat causes fata l d isease
in 50% of test subj ects
Fecal load : th e num be r of pathogens per gram in a sa mp le of hum an
o r animal feces
THE SCIENCE OF
serious or potentially fatal diseases, but they yield solid numbers for less severe diseases.
Different strains of the same pathogenic species can have
vastly different infectious doses. Some strains of E. coli, for
example, require as many as 100 million microorganisms for an
infection, whereas other strains can be infectious with as few as
50. Noroviruses have 1050 values estimated at fewer than 20
viral particles. For a few food borne pathogens, the 1050 is as
low as one-meaning that for half a population, ingesting
a single microbe is enough to cause an infection.
115
The technical term for the transmission of contaminated feces from one person to another is the
116
VO LUME 1
occurs primarily on the farm or in the slaughterhouse. Washing baths are particularly prone to
contamination by animal feces because even
2
a small fleck of feces in a washing tank that
Common Misconceptions
About Microbes
As we began looking closer at research on the
main kinds of foodborne pathogens, we were
frankly somewhat surprised to learn just how large
a fraction of foodborne illness is caused by contamination by human or animal fecal matter. Like
many people with culinary training, we had
assumed that the problem was intrinsic to the food
supply. Before a pig becomes pork, for example,
11 7
page 179.
The common fretting about trichinella is
a symptom of an enduring problem with the
page 126).
TRAFF IC ACCIDENTS:
FOODBORNE TOXOPLASMOSIS:
one in 6,500
one in 728,000
one in 68 million
118
The 2006 episode led to 205 confirmed illnesses, three deaths, and a tentative link to wild
boars living in the coastal mountains of Califor-
processing plant.
THE ETYMOLOGY OF
Disease Names
Just as biologists follow naming conventions for pathogens,
medical professionals have developed a method of naming
diseases. Several different approaches are used, which can
make things confusing to the uninitiated.
One common convention is to append "-osis" or "-asis" to
the root of the pathogen's genus. An infection with Trichinella
spp. therefore becomes trichinellosis. Medical authorities
sometimes modify this straightforward method to yield
less obvious derivatives. Thus, infection with the protist
119
PARASITIC WORMS
Fear of Trichinella spiralis, perhaps the most
12 0
supply.
The diversity of these organisms is underappre-
VOLUM E 1
2
How Trichinella Can Get into Meat
An invasive infection by worms, typified by the Trichinella life cycle, begins
when an animal consumes muscle tissue that contai ns encysted worm
larvae. Freed from the tissue by the new host's digestive process, the larvae
rapidly mature into male and female adults, whi ch mate and release new
larvae. Each larva burrows into a muscl e cell, co nve rting it in to a so-ca ll ed
nurse ce ll by sec reting proteins that promote the formation of blood
Life stages
(l
,..-
vesse ls. Blood vesse ls then grow around the larva and feed it. Larvae ca n
live in protective calcified cysts for yea rs until the host dies and is eaten,
whi ch sta rts the cycle anew in anoth er host.
Trichinella worms can survive refrigeration, but suffi cient freez ing will kill
the worms in pork. For othe r meats, and as an alternative for pork, safe
coo king practices will render any worms in the food harmless.
Contaminat ion
'\
Unsafe storage
Fresh meat is refrigerated.
but parasites survive.
--=
Unsafe cooking
4 a Meat is insufficiently
cooked
(either too quickly or at too low a
temperature), leaving viable parasites.
-~
=:::c=~
!
When ingested by another animal,
larvae leave cysts and travel to the
small intestine, where they mature.
Wild game
Safe storage
Wild game
Wild game
Pork
Wild game
Pork
Pori<
Safe cooking
4 b~--------~--~
Wild game
Pork
3b~--------~--~
Roundworms
Pork
121
irresponsible.
1 22
VO LUM E 1
2
Wild salmon, however, are especially prone to
fecal-oral route.
123
tomatic, although the parasites can cause abdominal pain, weight loss, or even intestinal blockage in
result in a far more serious disease called cysticercosis, in which the hatched larvae migrate to
1 24
VOLUME 1
PROTISTS
Protists, which encompass single-celled algae,
pseudopodia. In many protozoan species, individuals have a specific gender and engage in sexual
reproduction. They also produce egg-like bodies
called oocysts. Other varieties of protozoa reproduce asexually by simple cell division.
In fact, malaria, the single most deadly disease
affecting mankind at present, is caused by several
species of protists in the genus Plasmodium. This
126
2
The Strange Life Cycle of Toxoplasma gondii
Toxoplasma gondii has a rather bizarre way of reproducing a nd maturing
that involves a fi e ndish sort of rodent mind control. Cats-both wild and
domestic-se rve as the protist's ma in hosts, but infection with the
protist rarely causes symptoms in them. Cats typically acquire the
infection from th e rodents they eat, who get it from unwittingly ingest;ng cat feces.
In mice and rats, T. gondii larvae invade white blood ce lls, which carry
them through the bloodstream to muscle a nd brain tissue, where the
la rvae lodge within protective cysts. The devilish part occurs when the
parasites somehow alter the brain chemistry of their host so that an
infected rodent develops an unnatura l attraction to cat odor.
Wh e n, inevitably, a cat ingests one of these deluded mice, the cysts in
th e rodent meat burst in the eat's intestinal tract, freeing the protists to
begin reproduc ing and forming oocysts. For a few weeks after infection,
cats defecate oocysts, which can be passed on to humans, livestock, or
rodents through oral ex posure to contaminated feces or water.
illnesses.
atic cats, you should assume that all cat feces can be
six weeks.
1 27
Life stages
Oocysts are shed in cat feces.
Contamination
Cats are allowed in the kitchen,
raising the risk of fecal oocysts
contaminating food surfaces.
I I IlL
other meat from animals that consumed the oocysts, but such routes of
infectio n are very rare. Once in food, however, the oocysts are difficult
to destroy with heat. The best precaution is to keep cat feces well away
from food and the kitchen.
Unsafe storage
Refrigeration and most freezing
does not kill the parasite's cysts
in either meat or vegetables;
insufficient washing of vegetables
and kitchen surfaces allow them
Unsafe cooking
4a Meat is undercooked, leaving
risk of contaminated surface or
interior, and vegetables are
served raw after washing.
Meat
Vegetables
Safe cooking
Meat and vegetables are
properly cooked.
~~lt_
..
~~
II
c0
;o:
u~
Safe storage
3br---------=---~
u~
a foodborne pathogen.
128
HLL
contaminate kitchens.
1 29
BACTERIA
Bacteria are perhaps the most adaptable life forms
on earth. The tiny microbes survive and thrive in
130
smaller than that of a plant or an animal, researchers had by the end of2009 already completely
VO LUM E 1
The astounding diversity of bacteria is particuthe ones that are pathogenic can cause illness.
THE CLASSIFICATION OF
Bacterial Subspecies
Beyond the conventional genus-species naming system for
organisms, scientists often group members of a single
bacterial species into smaller divisions that reflect genetic
similarities or other shared features. These advanced
classifications provide progressively finer criteria for
distinguishing one microbe from another.
A subspecies is a genetically distinct population that is
often geographically isolated from other members of the
same species. The common food pathogen Salmonella
enterica, for example, has seven subspecies, including
S. enterica arizonae and S. enterica enterica. The latter is
the most common kind that is found in people and
warm-blooded animals with food poisoning.
Scientists can further divide closely related
species or subspecies by identifying distinguishing
characteristics, such as specific molecules or
genetic elements in the cells or their outer surfaces.
They refer to bacterial variants grouped this way as
a serovar (or serotype).
The relationship among bacterial serovars resembles that which exists among different tomato varieties.
The Sweet 100 cherry tomato cultivar, whose fruit weighs
a mere 28 g I 1 oz, for example, differs markedly from the
Goliath beefsteak tomato variety, which can yield fruits
weighing1.4 kg I 3 lb. Yet both types are readily identifiable
as tomatoes: Solanum lycopersicum.
Small genetic differences can likewise impart significant
variation among bacterial serovars, including the ability of
some to withstand multiple antibiotics. Sometimes those
differences are not even part of the microbe's heritable
genome but are conferred when unrelated plasmid DNA is
transferred from one bacterium to freeload on another (see
Plasm ids, next page).
Researchers have identified several thousand serovars of
S. enterica, nearly all of which belong to the enterica subspecies. Common serovars associated with food borne illness
132
2
botulinum releases a potent nerve toxin as it grows
Spoilage Bacteria
very sick.
Unfortunately, this situation can fool people
THE BIOLOG Y OF
Plasm ids
A plasmid is not a living thing but rather a self-copying piece
from viruses, which have fairly complicated protein structures around their DNA or RNA; plasm ids are just naked
the normal genetic blueprint of the microbe, often bestowing on the host bacterium dramatic
1 33
A Toxic Invasion
The secretions of some other foodborne bacteria
are not nearly as benign as those of their spoilagecausing cousins. Although some invasive infectious bacteria can cause disease without emitting
a toxin, most pathogenic ones release an associated bacterial toxin. Intriguing evidence suggests
that a bacterium can communicate with its kin by
emitting chemical signals, which allow a group of
microbes to gang up and coordinate their invasion. This process, called quorum sensing,
enables the bacteria to build up their numbers
before starting toxin production. Some researchers suspect this is why the onset of certain infections is so sudden.
Bacteria often secrete toxins specifically to
harm us. It's nothing personal; it's just part of their
Although spoilage and pathogenic bacteria
often contaminate food simultaneously,
you can never assume that the absence of
spoilage bacteria means the absence of
pathogens.
life cycle. A common strategy among gastrointestinal bacteria is to release toxins that bring on
compete for limited food resources. This strategy
is, in fact, the basis of fermentation, the process
by which food-dwelling microbes break sugars
down into acids or alcohols.
A great example of a bacterium that uses this
tactic is Lactobacillus bulgaricus, a species that
emits large quantities oflactic acid, preventing the
growth of most other bacteria. L. bulgaricus
thrives in the acid, which gives the food it inhabits
a distinctive odor and flavor. In certain contexts
this spoilage is, however, desirable.
For example, this is how yogurt is made.
Makers inoculate milk with a particular strain of
L . bulgaricus (or other related Lactobacillus species
or the lactic acid-producing bacteria Streptococcus
134
2
Other pathogens, including V. cholerae, are
better known as agents of waterborne disease-
Toxin production is typical of anaerobic pathogens such as Clostridium, but aerobic bacteria also
excessive temperatures.
THE ORIGIN OF
135
1 36
2
How Pathogenic. Coli Can Get into Food
Most va ri eti es of E. coli bacteria, which live in the ga strointestin al (GI) tracts
of humans and o th er wa rm-b lood ed anim als and are shed thro ugh th eir
feces, are eith er benefici al or harml ess. Th e sa me ca nnot be sa id for
pathogenic strains such as E. coli 01 57: H7, w hi ch has bee n blamed for
mu ltiple food born e outbreaks linked to contamin ated milk, meat, and
Life stages
1
Contamination
produ ce such as spin ach and alfalfa. Infections with pathoge nic strains
cause painful cramp ing and bloody diarrh ea. Th ey are particul arl y dangero us for young chi ldren and th e elderl y, in w hom life-threatening anemia and
kidn ey damage ca n d eve lo p. Fortun ately, good kitchen practices- including
safe sto rage and coo king- can minim ize the risk of infectio n.
Unsafe storage
Spinach is contaminated by
E. coli-laden feces at the farm.
Unsafe cooking
Spinach is unwashed or
insufficiently washed before
serving. Adding mayonnaise or
salad dressing may compound
contamination by fueling bacterial
"'"'''"~
Safe storage
3b~---------=--~
Spinach is refrigerated.
~~ lt_
II
<:;,
0
0
Safe cooking
1 37
temperature (56 c
THE RISKS OF
13 8
2
THE RISKS OF
Botulinum
Toxtn Type A
It
-~
~L
--
~OTOX
~osmetic
SNll. PATENT USE
53 78
LOT: C~ '
EXP.:
St
1 39
Contamination
life stages
Unsafe storage
3ar-----------~--~
Unsafe cooking
Most cooking conditions may
kill the bacteria, but the toxins can
Bacteria Spore
Toxin
Safe storage
Refrigeration, immediate serving.
and proper canning or sous vide
preparation can all curtail spore
germination.
~~ LL
11
2
c
0
3:
u~
11
"E
0
3:
0
u~
Bacteria Spore
140
Toxin
2
and roast a turkey that somehow has become
products.
141
BACTERIAL GROWTH
The ability of bacterial populations to grow
happen in minutes.
THE TERMINOLOGY OF
142
143
Chemicals as Preservatives
30
40
50
60
Regrettab ly, howeve r, si mplistic rules about the danger zo ne are misleading at best. Insid e the zo ne, the highe r temperatures are expo nentiall y risk ier
than the lowe r temperatures. It takes seve ral days for E. coli 0157:H7 to
multipl y at 5 oc I 40 oF as mu ch as it does in mere minutes at 38 oc 1 100 F,
for exa mpl e. For more on thi s subject, see chapte r 3 on Food Safety.
Temperature ("F)
80 90 100 110 120 130 140
70
0.5
0.5
40min
.;
...__
E
~
00
...__
0.4
50 min
.E
1h
::0
0.3
:J
::J
"-
"'E
;:;
00
0.2
...__
0.4
00 0.3
...__
::0
::J
:J
~ 0.2
00
-0
0.1
50
0
Temperature (oC)
144
0.1
6h
1d
6h
1d
pH - 12
60
"'
50 min -~
00
1h
"
oii
..Q
40min
.;
10
8
pH
12
14
2
The Limits of Bacterial Reproduction
Pathogenic food borne bacteri a stop reproducing below a certain minimum temperature and
above a certain maximum temp erature- and repli cate fastest within an optimal temperature
range. Th e acidity, or pH, of th e food also places limits on bacteri al multiplication.
Species
Bacillus cereus
Campylobacter jejuni
Clostridium botulinum Type A
C. botulinum Type B
C. botulinum Type E
C. petjringens
Escherichia coli (pathogenic)
Listeria monocytogenes
Salmonella spp.
Shigella spp.
Staphylococcus au reus
Vibrio cholerae
Yersinia enterocolitica
Lower
Upper
temp. limit temp. limit Fastest growth
(c)
("F)
("C)
( F)
("F)
("C)
Lower
pH limit
(pH )
Upper
pH limit
(pH )
39
55
131
28-40
82- 104
4.3
9.3
30
86
45
11 3
37-43
99- 109
4.9
9.5
10
so
so
48
11 9
30-40
86- 104
4.6
10
48
11 9
30-40
4.6
38
45
11 3
25-37
86-104
77-99
10
so
52
126
43-47
109-11 7
43
so
121
35-40
95-104
31
45
11 3
30-37
86-99
4.4
9.4
6
-1
5
41
47
11 6
35-37
95-99
3.7
9.5
43
48
11 7
37
99
4.8
9.3
44
so
122
35-40
95-104
10
10
-2
so
43
11 0
37
99
10
29
42
108
28-30
82-86
5
4.2
10
I 70 p or higher.
The 2007 USDA study confirmed the antimicrobial potency of a wine marinade with oregano
1 45
2
THE MATHEMATICS OF
m: ~ ~ A
3.00
3.00
s.oo
~ ~,._sc:'': =
14 7
BACTERIAL DEATH
For bacteria, death is very similar in some ways to
reproduction: it, too, is exponential. When
environmental conditions become lethal, bacteria
start to die-slowly at first, and then with increasing speed as conditions worsen.
In the kitchen, temperature-high temperature
in particular-provides the primary means of
killing bacteria. Refrigeration or even freezing
slows or stops the division of most bacteria of
concern to cooks, but it does not kill them as it
Above a critical threshold, the higher the temperature, the faster the bacteria expire; see The Limits
of Bacterial Reproduction on page 145.
Too often, presentations on food safety oversimplify how this works and give the misimpression that the critical temperature alone is what
matters. That is just not true. The process of
bacterial death is a function of both time and
temperature. Do not trust any food safety rule that
zation technique only a few years before publishing the first of his landmark studies on the role of
1 48
theory of disease.
Many people think pasteurization applies only
to heating dairy products to thwart pathogenic
bacteria, but practitioners use the term in other
contexts as well. Pasteur, in fact, first developed
the technique for storing wine and beer.
Sterilization is another widely used term.
VOLUME 1
2
Demystifying Logarithmic Reductions
90% reduction
99% reduction
m,J
a factor of 10.
149
A common ass umption in food science is that the same fraction of the
bacte ria in a particular food held at a part icular tempe rature di es off each
minute. That mea ns, for exa mple, that if90% of the bacteria die in the first
7 min at 58 oc / 136 F, then 90% of those that remain die in th e nex t 7 min,
and so on. In other words, th e popul ation falls ex pon entially ove r t im e, as
shown in th e top left chart below. Th e shape of this "thermal d eath cu rve"
ca n be summ ari zed by a power oflO (a loga rithm) called D, which is the
Definition
Tmin
minimum temperature needed to kill the organism (at least within the boundaries
of the study)
time needed to kill90% of organisms at the reference temperature (for a 10 drop)
reference temperature at which D,., is measured
change in temperature required to reduce the D value by a factor oflO
~--------------~
100r------------,r-------------------------------~
c
.2
80
Qj
60
Qj
0..
0..
"'
"'
-~
ti
"'
..0
~
u
40
"'
..0
Qj
Q)
..0
..0
E
::J
10
20
::J
10L_______~1L0--------2~0~------~3L0________4L0--~~--~
50
Cooking time (m inutes)
131
~
When cooked
.2
at 60 ' c, the
bacteria co unt
s
Qj
drops fro m
100 million to
10 million
0..
in 15 minutes ...
t"'
140
149
100
''
'
s0
~'
'''
'''
''
Q)
.:;
10
ti
..0
"0
"'
::J
Qj
"0
..0
~c
Dref
::J
At 60 oc I 140 OF,
Drer"" 15 minutes
10
15
45
0.1
15 0
55
60
Cooking temperature (C)
VOLUME 1
65
70
2
As the actual data poi nts from scientific stud ies show below, therma l
death curves vary from one kind of pathogen and food to another
Temperature ( F)
131
134 6
138.2
141 8
145 4
149
152 6
156 2oF
1 00 ~----~----.---~T=--~~----.-----.---~r-.
V>
.<::>
(l)
.,
':5
"'
10
a.
V>
10
(l)
tl
"'
.n
.=;
.,
0
;:;
."'5 0.1
.n
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:::>
z
~ 00
~
0
0
(l)
0
0.01
55
57
59
61
65
63
67
69
Tem perature ( C)
The graph below shows thermal death curves from the scientific literature for a 6.50
reduction of various pathogens: Salmonella spp. (red, a composite), Campylobacter jejuni
(blue), E. coli (green), and Trichinella spiralis (black). The lines cover the range of
temperatures tested; the typical assumption is that one can extrapolate the line to higher
temperatures, but it may not be valid to extrapolate to lower temperatures. If one line lies
below another. that means the pathogen indicated by the lower line is more heat-sensitive.
For example, E. coli is more heat sensitive than Salmonella. The Salmonella curve in red
is the basis for FDA cooking guidelines for many food borne pathogens (see chapter 3)
because it is a serious threat in its own right and its thermal death curve lies above those
of most of the other pathogens. So by the time Salmonella is reduced to the 6.50 level.
most other pathogens will have been reduced to an even greater extent. Note, however,
that some bacteria produce spores that are very heat-resistant.
Temperature ( F)
120
130
140
150
170
160
1h
10 min
V>
"0
c
0
u
(l)
E
;.=
1 min
30 s
E
;.=
10
(l)
50
55
60
65
70
75
80
151
VIRUSE S
Bacteria are tiny living things. Viruses are quite
different, so much so that they blur the distinction
infect a host cell by injecting or otherwise inserting the DNA or RNA into that cell, where it
1 52
2
freezing do not inactivate viruses, but heat can do
so. The thermal inactivation curve for a virus is
very similar to the thermal death curve for bacteria that we discussed in the previous section on
Notorious Noroviruses
foods, such as salad dressing, raspberries, sandwiches, and cake frosting, served in a wide range
THE MATHEMATICS OF
15 3
Life stages
hygiene and of keeping sick employees at home. The hardy particles often resist disinfection and chlorination attempts, but the risk can be reduced by carefully washing fruits and
vegetables, properly cooking oysters and shellfish, cleaning potentially infected surfaces
with bleach. and washing contaminated linens in hot water and detergent.
Contamination
Unsafe handling
Sick employees are allowed to
continue handling food and
surfaces, thereby increasing the
contamination risk.
Unsafe cooking
4a Contaminated food is served raw.
Safe cooking
Safe handling
Sick employees stay home:
hands are carefully washed; bleach
is used on kitchen surfaces.
154
2
Rotavirus and Hepatitis
Two other kinds of foodborne viruses, rotavirus
generally symptom-free. In other victims, symptoms can include sudden fever, nausea, appetite
loss, and abdominal pain, followed by jaundice.
Severe infections can persist for up to six months.
Hepatitis A is transmitted by direct contact,
usually with those who have poor hygiene-commonly, infected restaurant workers. The disease's
relatively long incubation period makes tracing
THE HISTORY OF
1 55
PRIONS
Prions-protein molecules that can take on
a misshapen, pathogenic form-are among the
strangest foodborne causes of disease yet discovered. For many years, prions filled a highly exotic
uniqueness led to tremendous scientific excitement, as well as two Nobel prizes. Despite this
1 56
countering critics, Stanley Prusiner of the University of California, San Francisco, won the 1997 Nobel
as mechanical devices such as gears. The conformation of the folded protein, like the type of gear,
VOLUM E 1
2
where the misfolded proteins tend to clump
together and leave tissue damaged and sponge-like
often accompanied by impaired muscular coordination, vision, memory, and judgment, as well as
personality changes. The disease can incubate for
1 57
THE GEOMETRY OF
Prion Diseases
A prion is an unusual protein that has (at least) two different
stable shapes, or conformations- call them C (for cellular)
and Sc (for scrapie, the disease prions cause in sheep).
Conformation Cis the default mode, the normal state for
the benign protein in the body. The alternative Sc conformation is associated with disease. Both forms comprise the
same sequence of amino-acid building blocks; the only
difference between them is their final shape, analogous to
the difference between ice and liquid water.
If one of the harmless C-type prions encounters its abnormally shaped Sc-type counterpart, something strange
happens: the protein in conformation C permanently switches
1 58
its shape to that of conformation Sc. Prions in the Sc conformation essentially act like recruiters, and the switching
process they initiate accelerates because each Sc prion can
convert more than one C prion.
Unfortunately, the Sc conformation is stable and irreversible. The process may resemble an infection in the way it
progresses, but the total number of protein molecules never
increases-only their shapes change.
The prion disease kuru causes voids (black spots, below left) to form around the neurons
(green spots) in the brain of an infected monkey, as seen through an electron microscope.
In variant Creutzfeldt-Jakob disease, prions collect into amyloid plaques (light object at
center, below right) in the brain of a mouse, as seen through an optical microscope.
2
THE BIOLOGY OF
outbreak appears to have run its course as BSEcontaminated beef has become rarer.
A related disorder known as chronic wasting
many of these countries, the problem of contaminated cattle feed, which may have contributed to
1 59
THE POLITICS OF
Cooking beef until it's well done will not reduce the risk of '" mad
cow'" disease; better safety rules for cattle feed, however, have
greatly reduced the incidence of BSE over the past decade.
1 60
2
Nevertheless, new elk brought to the facility still
developed CWD. The facility remains shuttered
Further Reading
Debre, P. Louis Pasteur. Johns Hopkins University
Press, 1998.
Friedman, M., eta!. "Recipes for Antimicrobial
Wine Marinades Against Bacillus cereus,
Escherichia coli 0157:H7, Listeria monocytogenes,
and Salmonella enterica," Journal of Food Science,
6:72, M207-M213; August 2007.
Mead, P., et al. "Food-Related Illness and Death in
the United States," Emerging Infectious Diseases,
6:5, 607-625; September-October 1999.
Prusiner, S. Prion Biology and Diseases.
CSHL Press, 2004.
Robinson, R., eta!. (editors). Encyclopedia of Food
Microbiology. Academic Press, 1999.
Sompayrac, L. How Pathogenic Viruses Work. Jones
and Bartlett, 2002.
Todar, K. Todar's Online Textbook of Bacteriology.
Available online at textbookofbacteriology.net
161
3
FOOD SAFETY
Researchers establish the scientific
basis for food safety in the laboratory, but it's up to
cooks to apply that knowledge in the kitchen. To
do so properly, we must ask ourselves two main
questions: "How can I prepare food that is safe?"
and "Am I following the appropriate laws and
regulations?"
To answer the first question, you must learn
how to apply a series of scientifically based-but
influence. You can't read a cookbook or foodrelated web site without encountering this wellmeaning counsel. "You must cook chicken to 74 c
in New York City, London, and Paris. The guidelines our mothers gave us may be no better. Some
health. It's not just a good idea for cooks in restaurants or other commercial settings to follow these
rules; it's the law! Your kitchen will be shut down
and dangerous.
not comply.
There's also a substantial set of informal food
FOOD SAFETY
DISCLAIMER:
This book cannot and
does not substitute for
legal advice about food
regulations in the United
States as a whole or in any
U.S. legal jurisdiction. Nor
can we guarantee that
following the information
presented here will prevent food borne illness_
Unfortunately, the many
variables associated with
food contamination make
eliminating all risk and
preventing all infections
virtually impossible. We
cannot accept responsibility for either health or
legal problems that may
result from following the
advice presented here. If
you operate a commercial
establishment and serve
food to the public, consult
the rules and health
regulations in your area.
1 65
us about issues of food safety. The first is laboratory experimentation: for example, testing how
of the pathogens within a specific food, for example, is called a 1D reduction (where D stands for
called epidemiology (from the root word "epidemic"); it tells us what happens in the real world.
You might think that scientific evidence would
makers take many other factors into consideration, including tradition, cultural trends, political
166
168
3
standards is that they protect against unlikely
Extreme simplification
FOOO SAFETY
1 69
cooking it. This assertion is scientifically incorrect: E. coli is very easy to kill with heat.
Evidently the officials decided that oversimplifying the public message was better than telling
the truth. They may have feared that if people
cooked contaminated spinach to make it safe to
eat, but either didn't cook it sufficiently or crosscontaminated other food or kitchen surfaces in the
process, more fatalities would result. The authorities must have decided that the benefits of avoiding multiple accidental deaths far outweighed the
costs of simply tossing out all spinach. In this case
they probably were right to make that decision.
The cost of some spinach is small compared to the
misery and expense of hospitalization.
Oversimplifying for the sake of public safety is
a very reasonable thing to do in the midst of an
outbreak or other health crisis. It may well have
saved lives to lie to the public and announce things
a cost. A chef's livelihood may depend on producing the best taste and texture for customers. Home
cooks who love food want it to taste the very best
that it can. To a person who cares about the quality
of food-or who makes a living based on it-excessive food safety standards don't come cheap.
A balance must be struck between the risk of
food borne illness and the desire for palatable food.
In cases such as those of pork and chicken, misleading the public about a rarely occurring scenario (while ignoring other, larger risks) arguably
offers little protection and comes at the cost of
millions of unnecessarily awful meals.
170
Culture Clash
3
appetite for rare pork; it isn't considered tradi-
THE POLITICS OF
FOOD SA FE TY
17 1
THE POLITICS OF
A food borne outbreak can readily test whether a government's epidemiological tools, consumer protection mechanisms, and regulatory systems are functioning properly.
A major outbreak of the pathogenic bacterium Escherichia
coli 0157:H7 in 2006 provided a telling look at all three.
In the summer and fall of that year, food borne. coli
0157:H7 sickened 205 people in the United States. Half of
them had to be hospitalized, and three died. Epidemiologists
were able to trace the outbreak back to fresh baby spinach
that had been packaged at a California facility on August 15,
but were unable to pinpoint the exact origins of the contamination. A joint investigation by the California Department of
Health Services and the U.S. Food and Drug Administration
(FDA), however, suggested that the contamination could have
begun in one of four implicated spinach fields exposed to the
feces of cattle or wild boar-or it could have stemmed from
tainted irrigation water.
A subsequent multi-agency study published by the Centers
for Disease Control and Prevention (CDC) concluded that
a surprisingly high number of bacterial isolates from the wild
boar, cattle, surface water, sediment, and soil at a ranch near
the outbreak matched the implicated. coli strain. It was the
first time. coli 0157:H7 had been isolated from wild boar in
the United States and the first indication that these animals
were either sentinels of, or active participants in, a potentially
overlooked mechanism of produce contamination.
Although it is difficult to know for sure what caused the
outbreak, the most likely scenario is rather complicated.
Herds of cattle in ranches near the spinach farms had members infected with. coli 0157:H7. This infection is not uncommon in cattle because it doesn't produce serious illness
in them. But the cattle were isolated from the spinach fields,
so how could they have caused the outbreak?
California, where the spinach was grown, is also home to
European wild boar that were imported in the 1920s to be
hunted but that broke free and interbred with feral pigs from
domestic farms. It appears that the wild boar became infected
from the cattle, probably by eating their feces. The boar then
broke into the spinach fields and defecated on the spinach.
Ironically, the last stage in the infection chain resulted from
conservation measures based on good intentions: facilities at
the packing plant washed the spinach, but then reused the
washing water, allowing contamination from only a tiny
fraction of the spinach to be spread throughout the entire
output of the plant.
17 2
the government.
paperwork.
a safety standard.
FOO D SAFET Y
1 73
COMMO N MISCONCEPTIONS
Once upon a time, some well-meaning officials
decided that food safety recommendations should
beef steaks:
(C) A raw or undercooked WHOLEMUSCLE, INTACT BEEF steak may be
served or offered for sale in a READY-TOEAT form if:
food.
Scientifically speaking, you need the right
steaks.
it's been verified in many tests: foodborne pathogens generally can't get inside an intact muscle.
174
with the skin intact. It's true that the risk of fecal
I 40 op and 140 op
FOO D SA FETY
1 75
II
tips from a processing company in Oklahoma caused Escherichia m/i-associated illness in Hi states, moving the USDA to
consider special labeling requirements for needled beef.
Cooks, beware: jaccarding a steak (as described on page
3-5()) poses the same risks because a jaccard tenderizer
1wrforates meat. The same is true for meat sold pretenderi,recL which is much more common than you might think .
During tenderization , the tinl'S carry pathogens into the
nwat, whl're they are less likely to lw killed by heat if the
meat is served rare .
If you are really concerned about till' contamination of
punctured meat, then you can dip the meat in a hot blanching bath for a short time or pass a torch over the meat 's
surface lwfore tenderizing it with a jaccard or other penetrating nwat tenderizer. For more clltail on blanching and
searing strategies, see pagl' 2267.
32 C I 90 F.
of microbial growth.
On chicken meat, for example, Salmonella
If you peruse the FDA 2009 Food Code, however, the "danger zone" turns out to be a much
be stored at 7 oc
54 oc
Although it doesn't make sense to
specify maximum and minimum
temperatures for the "danger zone,"
it is perfectly reasonable to do so
for holding temperatures, such as
the maximum permissible temperature for a refrigerator.
I 41 op or below) can
I 41- 135 oF. Or you
to cause illness.
Some simple calculations reveal the varied risk
I 130 F.
1 76
3
In the Zone
Food safety rul es typically spec ify a "d ange r zone of temperatures from
4.4-60 c I 40-140 r at which food cannot be left out for more than four
ho urs. But as th ese gra phs show, all temperatures within the danger zone
are not equ ally dange ro us. Th e top grap h shows th e wi ld ly different rates at
Temperature (F)
Temperature ( c)
Temperature (F)
40
1y
60
50
70
90
80
100
110
120
I 39.0 .,
12 wk
5 weeks at 48 c I 11 8.4 .,
4wk
.,
7d
f=
24 h
12 h
6h
10
20
30
40
50
Temperature ("C)
To offer another way to think about the differing risks posed by different temperatures, we
calculated how long at each temperature Salmonella would need on chicken to achieve the
same multiplication in number of bacteria that occurs in four hours at 41.5 cI 107 r. The
bacteria could sit at 4 cI 39 r for more than year, or at 48 cI 118 r for five weeks.
Salmonella bacteria begin to die at temperatures above 48 cI 118 F. At temperatures
below 4 cI 39 F, the bacteria stop growing but do not die, even when frozen.
FOOD SAFET Y
177
1 78
3
unlikely to cause problems. On the other hand,
highly contaminated food isn't safe to leave out for
any duration. Like other food safety rules, the
so-called "danger zone" directive is not a strict
rule-it is a subjective simplification of a complicated issue. That simplification is a useful way to
get a rule of thumb, but it isn't some deep scientific
truth.
Source
(c)
(r)
Time
71
160
no time
given
54
130
112 min
60
140
12 min
49
120
21 h
54
130
30min
61
142
1 min
I 144 p because the time required to eliminate the parasite would be less than a second.
62 c
a different standard for it. The cooking recommendations in the FDA time-and-temperature table
was also very rare: just 64 cases over five years, for
FOO D SA FET Y
The growing popu larity offreerange pork has spurred debate over
whether eating such meat might
increase the risks oftrichinellosis.
In a 2009 op-ed in The New York
Times, a free-range opponent
pointed to a study reporting that,
among pigs sampled from three
states, two free-range animals had
potential Trichinella exposure,
compared with none of the
conventionally raised pigs tested.
"For many years, the pork industry
has been assuring cooks that a little
pink in the pork is fine," he noted.
"Trichinosis, which can be deadly,
was assumed to be history." The
study, however, turned out to be
financed by the National Pork
Board, no friend of the free-range
movement.
17 9
Clostridium perfringens.
foodborne Salmonella.
3
Officially Recommende d Times and Temperatures
for Cooking Chicken
Tempera ture
(oc)
(of)
Time
74
165
no time given
74
165
15 s
U.S. Code of Federal Regulations, readyto-eat chicken; example times for 10% fat
content
58
136
81 min
60
140
35 min
63
145
13 min
I 136 F. Likewise,
74
165
<lOs
58
136
76m in42s
74
165
<10 5
juneja, 2007
6.5D reduction in Salmonella for ground
chicken breast meat
55
131
39 min 31 s
57.5
135.5
31 min
60
140
19 min 30 s
62.5
144.5
4min17s
55
131
1 h15 min
57.5
135.5
34min8s
juneja, 2007
6.5D reduction in Salmonella for ground
chicken thigh meat
60
140
32min
63
145
11 min18s
60
140
20 min 56 s
62.5
144.5
5 min 28 s
mended higher cooking temperatures to consumers than to makers of processed chicken products:
The temperatures recommended to consumers by the FSIS exceed those provided
tions, which are ostensibly based on safety considerations, are in reality based on bureaucrats'
beliefs about consumer preference. That is hardly
their charter! Shouldn't chefs and consumers be
the ones to decide what they would prefer to eat?
Perhaps the most galling aspect of this stance is
that the advisors are just wrong about the culinary
FOO D SA FE TY
181
UNDER STANDI NG
THE FDA RULE BOOK
Broadly speaking, health officials take two
approaches to food safety rules. One approach is
convection ovens must meet certain specifications. Humidified ovens, including combi ovens,
tions, although the FDA still provides a temperature recommendation as well as suggestions for
destroy pathogens."
relative humidity.
Raw foods are also governed by FDA regulations. In the case of raw fish, the FDA requires that
182
70 c
I 158 p is 11 seconds.
FOO D SA FE TY
183
(OC)
(oF)
Time
No te
fish
farmed meat, including that from commercially
raised game animals
eggs broken and cooked to order
63
145
15 s
63
145
3 min
66
150
1 min
68
155
15 s
70
158
<1 s
poultry
baluts
wild game animals
stuffed meat, fish, poultry, pasta
stuffing containing meat, fish, poultry, or ratites
74
165
15 s
54.4
130
112 min
55.0
13 1
89 min
56.1
133
56 min
57.2
135
36 min
57 .8
136
28 min
58.9
138
18 min
60.0
140
12 min
61.1
142
8 min
62.2
144
5 min
62.8
145
4 min
63.9
147
134 s
65 .0
149
85 s
66.1
151
54 s
67.2
153
34 s
68.3
155
22 s
69.4
157
14 s
70.0
158
Os
63
145
no time give n
74
165
no ti me give n
74
165
15 s
57
135
no ti me given
57
135
no time given
5D redu ction of "most res istant mi croorga nisms of publi c health significa nce"
1 84
3
FDA - Speel'fj e d c 00 mg r 1mes an dTem p e r a t ures
mil k paste urization for maki ng cheese
63
(continued)
145
30 min
72
162.1
15 s
89
191.2
1s
96
204.5
0 .05 s
100
212
0.01 s
69
155.6
30 min
80
175.6
25 s
your customers in writing on the menu or elsewhere. But the warning is not required if you
follow the 63 c I 145 p for 15 seconds rule. Why
make such an exception? We don't know, but it
seems to make no scientific sense.
Of course if you are serious about the safety of
lightly cooked eggs, the right thing to do is use
temperature of 63 c I 145 F, the time requirement of 15 seconds is dramatically less than the
necessarily safe.
FOOD SAFETY
165
Ove n typ e
(oC)
n>
Note
<4.5 kg I 10 lbs
still dry
177
350
convection
163
325
high-humidity
121
250
relative humidity must be greater than 90% for at least 1 has measured in the
cooking chamber or exit of the oven, or roast must be cooked in a moistureimpermeable bag that provides 100% humidity; temperature given is a recommendation but can be less
121
250
high-humidity
121
250
~4.5
kg l 10 lbs
So us vide specification
Regulation
cooked to temperatures and times as for other foods (see FDA-Specified Cooking Times and
Temperatures, page 184)
I 41 F
stored at 1 oc I 34 oF
stored at 5 oc
- 4 F)
(OC)
(oF)
Time
Note
- 20
-4
7d
-35
- 31
15 h
-35/-20
- 31 /-4
ld
one second at 76 oc
186
145 op has no
3
almost always done at 75 ' C I 170 ' For above;
The thermal death curve for a 6.5D reduction of Salmonella in beef (black line) has been established by many
scientific studies. The FDA's time-and-temperature recommendations for cooking whole-meat roasts (red dots)
accord well with the scientifically determined parameters, except for one notable deviation at 70 ' CI 158 ' F. Here
the FDA recommends cooking whole roasts for one second or less-a rule that flouts the scientific evidence and
could be downright dangerous because such a brief cooking time is unlikely to reduce Salmonella populations to
safe levels. The correct cooking time (blue dot) is 11 seconds.
Temperature ("F)
135
140
145
150
155
160
10,000
10 min
v.
"0
0
u
FDAJ-401.11 (6)(2)
Q)
100
1m in
_;
Q)
E
f=
30 s
10 s
Correct va lue
1s
Incorrect va lue
10
55
60
1.0
70
65
Temperature ("C)
reduce Salmonella counts by less than three-fold instead of the more than 3-million-fold drop
produced by using the 5 min cooking time suggested by the Salmonella curve. The single data
point for cooking the surface of beef (brown dot) is equally unlikely to yield a substantial drop
in pathogen levels. The FDA-recommended temperature for cooking poultry (purple dot}, on
the other hand, is needlessly high. It's even more conservative than the pasteurization curve
for dairy (pink line), which is based largely on outmoded methods of analysis. The curve for
ice cream (orange line) reflects concerns about the difficulty of destroying pathogens in eggs
and milk fat, but its accuracy has not been demonstrated.
Temperature (' F)
140
150
160
170
180
190
200
210
-oc
0
~
Q)
f=
0.1
Temperature ('C)
FOOD SAFETY
187
ture of74 c
as 58 c
milk to 72 oc
I II I II I ' I
I I
1: \
I I
strangely activist health departnwnt , which selms so determirll'd to meet its responsibilities that it errs on the side of
Officials at the health dlpartnwnt must haVl' noticed lwcauw, in till' first quarter of 2006, tlwy conducted raids on
188
3
Above 72 c I 162 p, the data points inexplica-
must be at least 57 c
I 135 F.
The FDA's more conservative time-andtemperature curve for ice cream reflects the fact
Temperature ( F)
r-~~----~------~~----~14T5~----~15T0~----~15T5~----~16To~----~1T
65~--~
What to Believe?
Government agencies have offered a range
of contradictory recommendations for
cooking poultry, as shown here. The FDA's
standard 6.5D Salmonella reduction curve
is shown in gray. The Food Safety and
Inspection Service (FSIS) of the USDA
recommends more conservative standards
for ready-to-eat poultry products
containing up to 10% fat (chicken
standards in purple; turkey standards in
green). More recent research by USDA
scientists, however, has yielded less
conservative recommendations for ground
chicken thighs (red line) and breasts (blue
line). The FDA, on the other hand,
recommends cooking poultry for 15
seconds at 74 cI 165 r (brown dot),
a ridiculously high temperature that is
scientifically unsubstantiated.
10 , 000
1h
1,000
lOmin
"'
"0
<::
0
u
"E
i=
"
100
E
i=
lmin
30s
lO s
55
60
65
70
10
75
Temperature (c)
FOOD SAFETY
189
conservative.
DISCLAIMER:
This book cannot and
does not substitute for
legal advice about food
regulations in the United
States as a whole or in any
U.S. legal jurisdiction. Nor
can we guarantee that
following the information
presented here will prevent food borne illness.
Unfortunately, the many
variables associated with
food contamination make
eliminating all risk and
preventing all infections
virtually impossible. We
cannot accept responsibility for either health or
legal problems that may
result from following the
advice presented here. If
you operate a commercial
establishment and serve
food to the public, consult
the rules and health
regulations in your area.
190
scientific research.
points have been interpolated for your convenience. The ice cream and sweet or high-fat dairy
Cooking sta nd a rd
Note
tuna
farmed salmon
wahoo, dorado, mahi-mahi, marlin,
swordfish, and other blue-water fish
that do not harbor anisakid
nematodes
freshwater fish
wild salmon
cod, flounder, fluke, haddock, halibut,
herring, mackerel, monkfish, pollack,
rockfish, sole, sea bass, turbot
other inshore saltwater fish
poultry (whole)
poultry (parts)
eggs
dairy pasteurization
192
5 oc / 41 F
72h
1 C / 34 F
30 d
- 20 C / - 4 OF
unlimited
5 oc / 41 F
14d
1 oc / 34 F
30d
- 20 C /-4 F
unlimited
the recommendations given in the Simplified Dairy table are likely excessive but meet
current standards
3
Extended and Simplified 6.50 Salmonella Reduction Table
The table at right incorporates FDArecommended cooking times (bounded
in red) for meat roasts for temperatures
from 54.4-68.9 c I 130-156 F, and it
extends the times to both higher and
lower temperatures by using the 6.5D
thermal death curve for Salmonella.
Times are given in hours (h), minutes
(m), and seconds (s).
oc
OF
Time
oc
OF
Time
oc
OF
Ti me
oc
OF
Tim e
52.0
125.6
5h 14m
54.4
130.0
1h 54m
60.6
141.0
9m 12s
66.7
152.0
44s
52.2
126.0
4h 46m
55.0
131.0
1h 31m
61.0
141.8
7m 39s
67.0
152.6
39s
61.1
142.0
7m 19s
67.8
154.0
28s
52.8
127.0
3h 48m
55.6
132.0
1h 12m
53.0
127.4
3h 28m
56D
132.8
1h
61.7
143.0
5m 49s
68.0
154.4
26s
62.0
143.6
5m 4s
689
156.0
18s
128.0
533
53.9
129.0
54.0
oc
OF
Time
55
131
7h
56
133
4h37m
57
135
3h
58
136
2h
59
138
1h20m
60
140
50m
61
142
33m
62
144
21m
145
63
64
15m
147
11m
149
65
10m
129.2
3h 1m
56.1
133.0
57m 31s
2h 24m
56.7
134.0
45m 44s
62.2
144.0
4m 37s
70.0
158.0
lls
62.8
145.0
3m 41s
71.1
160D
7.1 s
2h 17m
57.0
134.6
39m 51s
57.2
135.0
36m 22s
63.0
145.4
3m 21s
72.2
162.0
4.5s
146.0
2m 55s
75.0
167.0
1.4s
57.8
136.0
28m 55s
63.3
58.0
136.4
26m 23s
63.9
147.0
2m 19s
76.7
170.0
0.7s
147.2
2m 13s
77.0
170.6
0.6s
58.3
137.0
23m
64.0
58.9
138.0
18m 17s
64.4
148.0
1m 51s
79.4
175.0
0.23s
149.0
1m 28s
80.0
176.0
0.18s
59.0
138.2
17m 28s
65.0
59.4
139.0
14m 32s
65.6
150.0
1m lOs
82.2
180D
0.07s
60.0
140.0
11m 34s
66.0
150.8
58s
85.0
185.0
0.02s
Thigh
oc
OF
Time
oc
OF
55.0
131.0
39m 31s
55.0
131.0
1h 15m
55.6
132.0
36m 35s
55.6
132.0
57m 39s
132.8
48m 57s
Time
56.0
132.8
34m 55s
56.0
56.1
133.0
34m 35s
56.1
133.0
47m 14s
56.7
134.0
33m 4s
56.7
134.0
40m 30s
134.6
37m 34s
Temperature (F)
134
138
142
,.--:.:;-"----.....::;.-'----";"'----'
130
1h
146
-.;=.-----'-;"--:, 10,000
57.0
134.6
32m 16s
57.0
57.2
135.0
31m 43s
57.2
135.0
35m 56s
57.8
136.0
30m 14s
57.8
136.0
32m 32s
58.0
136.4
29m 32s
58.0
136.4
31m 22s
58.3
137.0
28m 22s
58.3
137.0
29m 42s
58.9
138.0
25m 58s
58.9
138.0
27m
59.0
138.2
25m 25s
59.0
138.2
26m 27s
59.4
139.0
22m 59s
59.4
139.0
24m Bs
60.0
140.0
19m 30s
60.0
140.0
20m 56s
60.6
141.0
15m 42s
60.6
141.0
17m 24s
61.0
141.8
12m 39s
61.0
141.8
14m 27s
61.1
142.0
11m 54s
61.1
142.0
13m 42s
Ground
thigh meat
.,
E
i=
1,000
10 min
54
56
58
60
Temperature (0 C)
62
FOOD SAFETY
61.7
143.0
Bm 24s
61.7C
143.0
10m 5s
62.0
143.6
6m 34s
62.0
143.6
Bm 5s
62.2
144.0
5m 29s
62.2
144.0
6m 51s
62.8
145.0
3m 17s
62.8
145.0
4m 15s
63.0
145.4
2m 36s
63.0
145.4
3m 24s
193
(min) (s)
Temperature
(oc)
(oF)
(min )
(s)
68.0
154.4
34
38
Time
Time
62.8
145.0
33
46
63.0
145.4
30
00
68.3
155.0
30
00
63.3
146.0
25
08
68.9
156.0
23
37
63.9
147.0
18
42
69.0
156.2
22
31
64.0
147.2
17
37
69.4
157.0
18
35
64.4
148.0
13
55
70.0
158.0
14
38
65.0
149.0
10
21
70.6
159.0
11
31
65 .6
150.0
42
71.0
159.8
31
66.0
150.8
OS
71.1
160.0
04
66.1
151 .0
44
71.7
161.0
08
66.7
152.0
16
72.0
161.6
11
67.0
152.6
34
72.2
162.0
37
67.2
153.0
10
72.8
163.0
25
67.8
154.0
22
73 .0
163.4
01
68.0
154.4
06
73.3
164.0
29
68.3
155.0
45
73.9
165 .0
44
68.9
156.0
18
74.0
165.2
37
nitrogen at -195 oc
69.0
156.2
14
74.4
166.0
09
69.4
157.0
58
75.0
167.0
42
70.0
158.0
43
75.6
168.0
20
70.6
159.0
32
76.0
168.8
06
71 .0
159.8
26
76.1
169.0
03
71.1
160.0
24
76.7
170.0
71.7
161.0
18
77.0
170.6
43
72.0
161.6
15
77.2
171.0
39
72.2
162.0
13
77.8
172.0
31
72.8
163 .0
9.9
78.0
172.4
28
73.0
163.4
8.8
78.3
173.0
24
73.3
164.0
7.4
78.9
174.0
19
73.9
165.0
5.5
79.0
174.2
18
74.0
165 .2
5.2
79.4
175.0
15
74.4
166.0
4.1
80.0
176.0
12
75.0
167.0
3.0
80.6
177.0
9.3
75.6
168.0
2.3
81.0
177.8
7.7
76.0
168.8
1.8
81.1
178.0
7.3
76.1
169.0
1.7
81.7
179.0
5.8
76.7
170.0
1.3
82.0
179.6
5.0
77.0
170.6
1.0
82.2
180.0
4.5
50
77.2
171.0
0.9
82.8
181.0
3.6
Temperature
77.8
172.0
0.7
83.0
181.4
3.2
(oC)
(oF)
Time
Note
78.0
172.4
0.6
83 .3
182.0
2.8
- 20
-4
7d
78.3
173.0
0.5
83 .9
183 .0
2.2
78.9
174.0
0.4
84.0
183 .2
2.1
- 35
- 31
15 h
79.0
174.2
0.4
84.4
184.0
1.7
- 35 to - 20
- 31 to - 4
1d
79.4
175.0
0.3
85 .0
185.0
1.4
80.0
176.0
0.2
85.6
186.0
1.1
1 94
3
THE BASICS OF
Just as building a large structure without a full set of blueprints would be foolhardy, an incomplete HACCP plan would
2.
3.
1.
5.
6.
7.
FOOD SAFETY
195
HYGIENE
Of all the miracle cures and preventive wonders
Personal Hygien e
1 96
excuse. Store the brushes under the sink; alternatively, chefs can carry them in their pockets.
The single most important time to wash your
hands is after using the bathroom. It seems
surfaces.
FOOD SAFETY
197
Kitchen Hygiene
200
ingly common, but again, it's important to understand its limitations. Alcohol, for example, isn't
FOOD SAFETY
201
exposed become submerged. It also means opening shears and other tools with mating surfaces
and apply it directly to refrigerator shelves, counters, floors, and heavy-duty equipment like meat
safety of food.
THE CONTROVERSY OF
weight down plastic boards until they're completely submerged . Also, if you stack the boards horizontally, the bleach
solution may not be able to get between them.
plastic boards.
Research suggests, however, that wood has natural antibacterial activity that helps to disinfect the board surface. True,
water may not be able to permeate deep scratches and scars
in the wood, due to surface tension. But cut wood secretes
antimicrobial compounds that help keep those fissures clean.
For the rest, you can scrub wood with salt as a scouring agent,
then rinse it with a 200 ppm bleach solution.
Many kitchens soak their cutting boards in a bleach solution overnight. That's not appropriate for wood. But be aware
that plastic floats, so to ensure proper sanitization you must
204
3
A growing number of companies also sell
ultraviolet light kits for sterilizing boards, knives,
and other utensils. These kits use shortwave
in a refrigerator.
transfer is proportional to the difference in temperature between food and air, letting the first 20 oc I
Temperature Control
People do dumb things to their refrigerators and
'tl
1/
'
I 40 F. Recog-
205
I II I
II\ <,I
! ',
I 2.7 p.
I 4.5 p,
"'
testing pmitive.
To minimize that risk, we advocate pasteurizing ice cream
in a sous vide bag. Put the bagged ice crcam base into a
cook tlw base in a pot and scrape it down with a spatula that
pcrhaps has only been rinsed off, and then pcrhaps transfer
till' base to a container that went through the dishwasher. To
do the transfer, you may pour the base through a fine-mesh
sicvc - a tool that is exceedingly hard to clean.
hom a food safety perspective, this is a recipe not for
dcssert but for disaster. The problem with ice cream is that
206
VOLUME 1
Further Reading
FOOD SAFETY
207
are often
foods are good for you and which are not. That
but with a totally different set of foods and cooking methods. Banking on an ever-growing number
Too much of a good thing is often bad for you, and that is certainly
true for many kinds of food that taste good. But popular notions
that certain types of food-those high in saturated fat. for
example-should be avoided at all costs are beliefs that have little
or no direct scientific support.
2 11
evidence with others, we commonly hear reactions such as "But everybody knows that isn't so!"
But science doesn't purport to reveal truthmerely the best explanation that is fully consistent
with all the facts available. That is especially
pertinent in nutrition and epidemiology, where
vant to gastronomy.
The sad truth is that it is much easier to dis-
source or preparation.
4
CONTROVERSIES
213
DIETARY SYSTEMS
The rise and fall of dietary fiber illuminates the
typical trajectory of a dietary system. You may
a specific diet and another that eats normallyand that then tracks the health of every subject.
Even then, chance can play a role, so results
cannot be considered definitive until several such
cancer in Africa.
2 14
4
actually showed a higher risk of colorectal cancer,
although the increase was so small that it was
Dodging Reality
Burkitt did not live to see his theory refuted. At
the time of his death in 1993, he was still being
feted for his great fiber discovery. One might think
that, confronted with such strong evidence that
RECOMMENDED FOR
All THE RIGHT REASONS!
WEIGHT LOSS
Individuals controlling caloric intake to
promote weight loss or weight maintenance can
benefit from including Uncle Sam cereal at
breakfast, as a topping for yogurt or couage
cheese, or sprinkled on salads because it
packs a high amount of nutrients for very few
calories. Also, the high fiber, low sugar ratio,
in combination with the omega-3 fatty
acids, makes it very satisfying.
.:'-
.,~.
FLAXSEED
LOW GLYCEMIC
'
..
LOW SODIUM
One serving of Uncle Sam cereal has
only 135mg of sodium, about the
amount in a cup of milk, and only a
small portion of the 2300mg per
day maximum recommended in the
U.S. Dietary Guidelines.
PR ESERVATIV E FREE
Uncle Sam cereal is a natural food!
We add no artiticialcolors. no artificial
flavon; . and no preservatives.
Health claims dominate the packaging of many kinds of foods these days. But these promises are rarely based on
sound science, and government authorities do little to keep manufacturers from stretching the truth.
215
T IMELINE
2 16
have not been confirmed by more rigorous examination, a skeptic would say there is no reason to
4
2008 The American Cancer Society states, " Links
between fiber and cancer risk are weak, but eating
these foods is still recommended "
1994
tal adenomas
2006
A randomized, controlled
50,000 women
80,000 women
Participants: 19.541
Participants: 958
Participants: 719
Participants with disease: 338 (47.0%)
Participants: 29.294
Participants: 947
Participants: 584
-SO%
-SO%
-50%
0 +8%
Equal
risk
+50%
Higher risk for
0%
+50%
-1%
+SO%
intervention group
217
Studies, page 221). The most rigorous is a prospective randomized, controlled clinical trial. Burkitt
was a surgeon, however, not an epidemiologist,
experimentally.
2 18
in this example).
219
Before you get alarmed, look at the 95% confidence interval (the error bars on the chart). This
design. In the case of the Women's Health Initiative study, the 95% confidence interval spans the
range from 0.90- 1.29-that is, from a 10% reduction in cancer risk to a 29% increase in risk. The
study lacked the statistical power to distinguish
which number in that range represents the true
How large is large enough to assure researchers that the results are not due to chance or bias?
To estimate the right size, scientists must factor
experimental practices commonly used in epidemiological research often produce misleading results.
220
VOLUME 1
Case-control study
Cohort, or
prospective, study
Kind
observation
observation
observation
intervention
Design
Strengths
Weaknesses
Weakest
Strongest
CONTROVERSIES
221
so these substances remain liquid at room temperature. If the fatty acid molecule has just one
222
llw
Many hypotheses are wrong. A completely rational scientist would not get too excited about a new idea until it is proved . But
scientists are people, too, and many find it impossible to resist charging ahead before then. It's only human that they focus
on the potential life-enhancing benefits and want to get these to people quickly; in this view, it is a public health issue as
much as a matter for dispassionate scientific inquiry. As side benefits, promising-sounding health ideas can bring fame and
larger research grants. Outside of science, food companies and retailers are driven mainly by the quest for profits; they tend
to see health claims as a way to promote new products. These players and motives interact with the slow-moving process of
scientific investigation to produce a common life cycle for dietary systems that emerge from medicine .
CD
EXAMPLE: FIBER
A charismatic scientist or
medical doctor champions
the cause and proselytizes to
other researchers and the
public at large about his or her
point of view. A dietary system
is born.
In the ea rly 1970s, Burkitt
and his colleagues publish
wide ly in scientific
journals.
@ A long-term
prospective study is
launched but won't have
results for many years.
In 1976, Nurses' Health
Study is launched.
While designed to
investigate hea lth
effects of The Pill, it
provides data on diet
Government
agencies are lobbied to
include the dietary
system in official
recommendations and
to allow food companies to advertise health
benefits to the public.
a troubled past.
policy makers, thus setting in motion an examination that continues to this day of how dietary fat
Kaslli
'""'_.-,..._c---.
eart
RED
CE (HOLE TEROL
Organic
Echinacea PI~&
cholesterol, but it has different destinations depending on which lipoprotein assemblage it is carried by.
good for you and the other likely bad for you. If in
fact one is good and the other is bad, the sum of the
two isn't going to tell you who is at risk. A new
generation ofblood tests was thus rolled out to the
body contained within large molecular assemblages made mostly of compounds called lipo-
the simple good/ bad dichotomy to be an oversimplification. LDL comes in several forms, including
in the blood vessels. Other forms, called lowdensity lipoproteins, or LDL, are the delivery
heart disease.
Characteristics
Diameter
(angstroms)
Density
(g/ml)
very-low-density lipoprotein
(VLDL)
300-700
0.95-1.01
intermediate-density
lipoprotein (IDL)
270-300
1.01-1.02
formed from VLDL when it has deposited some of its cholesterol; includes at least
seven subclasses of LDL
220-285
1.02-1.06
densest of the LDLs known so far; associated with a higher risk of heart disease
220-255
1.04-1.05
high-density lipoprotein
(HDL)
70-100
1.06-1.21
226
4
approximately correct. One study found that the
formula underestimated LDL levels by 20 points,
disease?
benefit.
chemistry that seems to negate the quite substantial benefits that statins give men. Many research-
mon cause.
We know at least that LDL is not the only cause
of heart disease because there are well-documented
cases of people who had very low cholesterol levels
(including low LDL levels) but nevertheless
suffered from serious heart disease. Some cardio-
heart disease.
Study 2: SEAS
Study 1: ENHANCE
suggests that the link between cholesterol-particularly LDL cholesterol-and heart disease is
not as simple as conventional wisdom suggests.
Indeed, some critics point to this as proof that
Trials of a Cholesterol-Lowering
Drug and Heart Disease
Two ra ndomized, cont rolled
clinical trials demonstrated that the
drug Vyto rin does not decrease the
incidence of heart disease, even
though it is effective at lowering
LD Lcholesterol and increasing
HD Lcholesterol.
- 4%
~
Equal
risk
+SO%
may also help to explain why statins lower cholesterol in women without preventing heart disease.
227
CONTROVERS IES
4
Fat and Heart Disease
people, the more fat they eat, the higher the total
-2%
+
Equal
risk
+50%
-50%
-7%
I
+50%
-50%
+6%
+50%
I
(no confidence interval reported)
229
The Minnesota Coronary Survey was particularly interesting. It included both men and women,
and stroke. They found no increased risk. Interestingly, they did find increased risk associated
gathered during more than 20 years of observation. The authors determined that "there is no
TIMELINE
230
Omega-3 fats, for example, are found in coldwater fish, as well as in animals, like seals, that eat
23 1
Study 2: DART 2
Studied outcome: death from any cause
among men who had already suffered a heart
attack
Study duration: three to nine years
Study 3: GISSI-Prevenzione
Studied outcome: death. stroke, or heart
attack among subjects who had already
suffered a heart attack
Study duration: 3.5 years
Participants: 5.658
Deaths: 621 (11.0%)
-SO% -29%
-50%
0
Equal
risk
+50%
+15%
Higherrisk for
+50%
-50%
-20%
+50%
intervention group
4
Trials of Dietary Fat and Cancer
Cancer is as much a public health priority as heart disease, so researchers have also investigated with
some rigor whether eating fat is connected to cancer risks. So far, however, science has established no
such link. The randomized, controlled clinical trials summarized below found that lowering fat
consumption does not decrease the incidence of cancer.
Study 1: Women's Healthy Eating
and Living
Studied outcome: new or recurring breast
cancer
Study duration: seven years
-SO%
- 4%
+50%
Equal
risk
-50%
- 9% 0
+50%
-50%
-17%
+50%
-50%
(-61%)
0 +12%
+50%
(+210%)
intervention group
THE CHEMISTRY OF
What's in a Fat
First we were told that all fat was bad, then th at all saturated fat was bad . Now a closer look at the individual fatty
acids of which all fats are composed reveals that "good "
and "bad" fats really have similar chemical compositions.
Olive oil, which has a reputation as a healthful fat, is
mostly oleic acid, which does not raise LDL cholesterol. But
the fat in cooked steak is also nearly half oleic acid . And the
majority of bacon's fat is oleic acid, too.
The principal other fats in cooked bacon and steak are the
saturated fats palmitic acid, which has been found to raise
LDL cholesterol (yet is also present in olive oil), and stearic
acid, which the body rapidly metabolizes into oleic acid.
Not So Different
The graphs below show the total fat (left) and palmitic, oleic, and stearic fatty acids (in
purple, blue, and orange, respectively, at right) in 100 grams of olive oil, cooked bacon,
and cooked steak.
100
100
80
~
"'c
~
~ 60
0o_
';"
.g
0
c..
"'
""
.2:
40
80
60
40
Qj
"'
20
20
0
Olive o il
Po rterhou se stea k
Olive oil
Baco n
Porterhouse stea k
233
Systolic
-4mmHg
+4
Systolic
-4mmHg
-2.1
Diastolic
-4mm Hg
-1.2 0
-+
+4
Diastolic
-4mmHg
-1.2
+4
Systolic
-8mmHg
I
- 5.5
-0.7 0
+4
Diastolic
-8mmHg
s: 115/S: 75
+8
Systolic
-8mmHg
+8
-6.7
Diastolic
-8mmHg
+8
+
-3.5
-3.0
Normal systolic/diastolic
blood pressure, in mm of
mercury (mm Hg):
+8
140-159/ 90- 99
Hypertension, stage 2:
Prehypertension:
120-139/ 80-89
Hypertension, stage 1:
~ 160/~ 100
234
CONTROVERSIES
Vitamin Supplements
Vitamins are critical nutrients that our bodies don't make, so
we must get them from food . When human diets are restricted (or when we get too little sun exposure to synthesize
the vitamin D we need), our health can suffer.
Fortunately, chemists can synthesize or derive large quantities of nearly any nutrient, allowing medicine to achieve heroic
victories over scourges caused by vitamin deficiencies. The
thiamine deficiency beriberi and the niacin deficiency pellagra are now rare. Rickets, a vitamin D deficiency, was widespread well into the 20th century before fortification of milk
and other foods largely eradicated it in richer countries. More
recently, an aggressive campaign to fortify foods and prenatal
vitamins with folic acid dramatically decreased the incidence
of the spinal-column defect spina bifid a in newborns.
These public health successes led to great enthusiasm about
vitamins. Tantalizing small studies suggested that people who
eat a variety of fresh foods have lower incidences of cancer
and heart disease. These results added to the buzz. So did
laboratory test results showing that certain vitamins (especi ally the antioxidants, which include beta-carotene, lycopene,
and vitamins A, C, and E) seem to protect human cells from
wear and tear (when studied outside the body).
Healthcare practitioners understandably hoped to employ
vitamins as preventatives, sort of a "good diet in pill form " that
might compensate for some of our bad habits. Active marketing by supplement manufacturers and retailers pushed this
view as well, with great success in the market: half of Americans now pop vitamin supplements routinely, generating
more than $20 billion in annual sales.
Yet as large-scale clinical trials have tested the benefits of
vitamin supplements, they have yielded results that are at best
confusing. One early randomized, controlled study gave the
nutrient selenium to people who had already had skin cancer.
It had no effect on whether the cancer recurred-but, intriguingly, overall mortality fell by half and cancer mortality fell by
one-third among the subjects taking selenium. The interven-
FOO D AN D HE AL T H
235
higher in those who ate the most salt, but the 95%
confidence interval allowed that the risk might
intakes have higher rates of death from cardiovascular problems and from all causes.
These varied results illustrate that there's no
one-size-fits-all dose of salt that ensures good
just as much salt (more than the U.S. recommended daily allowance) as their peers.
These data speak well of eating a diet rich in
236
TIMELINE
"on average, the higher an individual 's salt intake, the higher
an individual 's blood pressure. Nearly all Americans
pressure"
2001
A second
2004 A meta-analysis of 57 randomized, controlled trials finds that healthy subjects without
strongly related to
blood pressure
blood pressure
237
THE B I O L OGY O F
1.lB
VOLUME 1
Classification
<18.5
underweight
18.5-24.99
normal weight
~ 25
overweight
~ 30
obese
Dr.
24 0
"';;:z
::;
4
juice or eating the fruit combined with protein
promotes weight loss, the diet-which restricts
carbohydrates to vegetables and grapefruit-averages so few calories per day that most people will
inevitably lose weight in the short term.
One small study has shown that the addition
of grapefruit to one's diet might be more than
old-time lore: 91 obese patients with metabolic
syndrome were randomized to take either
placebo or grapefruit in various forms-capsule,
juice, or fresh-for 12 weeks. Everyone who
consumed grapefruit lost weight and had improved insulin responses after eating (meaning
their bodies more appropriately drew glucose
from their blood into their cells), but those who
ate half a fresh grapefruit before each meal lost
the most weight (1.6 kg I 3.6lb over three
months) and had the best postmeal insulin
profile. The authors note that half a fresh grapefruit has fewer calories than the quantity of
grapefruit juice that the subjects drank and more
fiber, which promotes a feeling of fullness. The
acidity of grapefruit may also keep food in the
stomach longer, delaying the return of hunger.
The Shangri-La diet, developed by a psychologist, supposes that foods that are familiar and rich
will prompt the brain to crave more of them,
leading to weight gain. Foods that are unfamiliar
and bland will trick the brain into thinking food is
scarce, thus lowering the body's "set point," or
and death from cancer, and incidence of Parkinson's and Alzheimer's disease.
Weight Watchers
A much more robust set of studies has looked at
Weight Watchers, one of the most enduring diet
programs. Initially just an informal support
group, Weight Watchers has developed into
a multifaceted, multitrack weight loss plan. Many
nutrition experts approve ofWeight Watchers
because it stresses that weight loss and mainte-
MiU
Weight-stable women
6.9 kg /15.2 lb
Mild weightcyclers
8.5 kg /18.81b
Severe weight-cyclers
24 1
242
grams of carbohydrates.
triglycerides and raised HDL ("good") cholesterol. The effect oflow-carbohydrat e diets on LDL
("bad") cholesterol varied from study to study,
to dietary fat.
regular dairy, and sugar, along with most processed foods, should be avoided.
was significantly increased. When the Mediterranean diet was included in comparisons, it gener-
VOLUME 1
4
CONTROVERSIES
243
Vegetarianism
All vegetarians avoid eating the flesh of animals,
but some restrict their diets further. Vegans do not
244
nonvegetarian counterparts.
that a vegetarian diet is to blame for these troubles. It may be that people with physical and
ailments.
vice versa.
VOLUME 1
Organic Food
labeling because they are extracted from plantsbut that doesn't make them any less potentially
harmful to humans than other pesticides are.
Billions of dollars in revenue ride on the ability
of manufacturers to claim their food is "organic."
hazardous contaminants.
245
4
"artificial" sweeteners, and so on-the antithesis
Raw Food
At the beginning of the organic food movement, the organic label usually meant a small
247
enzymes in food.
supply.
THE CHEMISTRY OF
248
any claim that a diet removes toxins from the body is almost
certai nly false.
Your body does not produce toxins that need to be exorcised. Although waste products of metabolism, including
carbon dioxide and urea, must be expelled, they are not toxic
in the sense that they cause poisoning in a healthy person .
Indeed, waste products from metabolism are always found at
some level in your body. True toxins, on the other hand, kill or
harm you even at low concentrations.
Statements to the effect that meat or cooked food is "full of
toxins" are plainly false (see Is Grilled Meat Bad for You? on
page 221). Many foods do contain small quantities of naturally
occurring substances that can, in high concentrations, be
harmful (see Natural Toxins, next page). But there is no general
need to "flush" these toxins, and claims that particular dietary
systems or food items exert a beneficial effect by removing
these so-called toxins are not backed by scientific evidence.
The theme of purification is common to virtually all food
superstitio ns and shamanistic practices throughout history,
so it's not surprising that advocates of fad dietary systems
promote the removal of "toxins." It is the dietary equivalent
of exorcising demons or evil spirits. To sell people on
a scheme you need to tell a story, and a purification story
makes intrinsic sense to people, even if the details turn out
to be false.
disease.
Most raw food dieters in yet another study had
Natural Toxins
Many of these chemicals are present in a variety of foods, but poisonings involving th ese
particular vegetables have mad e th em th e poster children for natural toxin s.
Potato
Toxin: glycoalkaloids
Effect: ca us es seve re stomachache, nausea, vomiting, diffi culty
breathin g, eve n death
Red kidney bean
Rhubarb
249
MODERNIS T INGREDIEN TS
Modernist cooking is in many ways defined by its
use of ingredients-as well as techniques and
examination.
compounds.
reputation.
250
flavor compounds.
#2 to remain in use.
These examples suggest that the FDA is quick to
252
food additives with pesticides and other nonorganic farming practices. It is common to hear
members of the public, including chefs, say in
a single breath that they don't want "chemical
additives, preservatives, or pesticides" in their
The same is true of many Modernist ingredients-see The Newfangled Naturals, page 257.
fermentation by bacteria.
253
a chef's kitchen.
Indeed, most Modernist ingredients have
received much more testing than the familiarseeming food in our home pantries. Traditional
ingredients have been ushered past regulatory
review by a grandfather clause that goes by the
term "GRAS," which stands for "generally recognized as safe." These foods have not been subjected
to carefully controlled tests and protocols.
It is often argued that sucrose-common table
sugar-would face an uphill battle if it came up for
approval as a new food additive. After all, it is
refined in an industrial process, and it clearly can
cause harm by promoting obesity, diabetes, and
tooth decay. Because sucrose, which was originally sold in small quantities in apothecary shops
as an exotic additive, met GRAS criteria, it has
largely avoided the intense regulatory scrutiny
that newer additives face.
In truth, the most important difference between so-called "artificial" additives and traditional additives like sucrose, baking soda, and
baking powder is that the newer additives were
completely tested for safety, whereas their older
GRAS cousins entered the market in more lax
times and thus escaped such testing.
254
4
generally not be very pure because the source
material also contains extraneous substances.
Moreover, the amount of ascorbic acid present in
a particular rose hip depends on the plant's
nutrition, the amount of sun it got, and other
variables. So the concentration of naturally
derived vitamin C tends to be highly variable.
Inconsistency of this kind is a common problem
with natural foods. Compare a peach at the peak
of ripeness taken directly from the tree with
a hard, unripe, out-of-season peach picked green
and then shipped thousands of miles. The two are
hard to recognize as the same fruit. That variability can pose real problems when cooking and
developing new recipes.
But ascorbic acid can be synthesized easily, and
the synthetic compound is identical to the natural
product. It is much easier to purify, however, so its
strength and concentration can be guaranteed.
There is no scientific reason to prefer the natural
product, with its impurities and variable concentration, to the pure synthetic. Indeed, just the
opposite is true.
The same can be said for baking soda and
of chemical reactions, produces sodium bicarbonate from salt brine and limestone. These ingredients are also sometimes purified from mineral
caustic salt found in dry desert lake beds.
Neither approach is "natural" by most definitions, yet most chefs don't think of baking soda
of the conventional wisdom or popular viewpoint. Advocates want to keep selling diet books,
maintain an aura of authority, and food companies want to keep selling products for which they
ingredients.
unrelated to diet.
255
THE HISTORY OF
food experiences.
Further Reading
258
259
avenues for culinary innovation because it expands our vision of the almost unlimited ways in
which food can be transformed. That's why the
263
THE NATUR E OF
HEAT AND TEMPER ATURE
Energy is a fundamental attribute of every physical system in the universe-so fundamental that it
practically eludes our capacity to define it. Standard physics textbooks define energy as "the
capacity of a system to do work." But the concept
of work is also maddeningly abstract. An informal
Like engineers and the public at
large, we use "heat" throughout the
book to refer to thermal energythat is, a form of internal energy
that affects the temperature of an
object or substance. The strict
scientific definition of heat,
however, is different: heat is
energy in transit from bits of
matter at a higher temperature to
other bits of matter at a lower
temperature. In the language of
thermodynamics, heat is actually
a process, not a property.
countless molecules.
264
5
these particles without sophisticated tools. What
cool the pan, and the steamy skillet will heat the
lower-temperature) matter.
THE HISTORY OF
Defining Temperature
We don't normally think of temperature as a measure of speed. But that is essentially
whattemperature is. To be precise, it is a quantity proportional to the square of the
average speed of molecules in a given substance as they wiggle in random directions.
Working independently, the 19th-century physicists James Clerk Maxwell and
Ludwig Boltzmann worked out the math that connects the speed of particles in a gas to
the temperature of the gas. Maxwell and Boltzmann were early believers in the existence of atoms and molecules, and their work on energy distributions still serves as a
foundation of statistical mechanics. But their ideas were controversial in their time, and
the controversy drove Boltzmann to despair. He committed suicide in 1906.
Speed(mph)
200
600
1,000
800
Gas temperature: 0 oc
1,200
1,400
32 F
100 c 1 212 . ,
"'
.!!:'
u
200 c I 390 . ,
400 c I 750 . ,
::l
Q)
c:
.t
100
200
300
400
500
600
Speed (m/ s)
Molecules inside a bottle of oxygen gas that is at equilibrium at 0 (/ 32 oFjostle at a wide
range of speeds (diagram at right and brown curve in chart above); 400 mls (1.440 kph I
900 mph) is the most common. At higher temperatures. such as 100 oc I 212 oF(violet curve).
200 oc I 390 oF(blue curve), and 400 oc I 750 oF(green curve). the average speed of the
molecules is greater, but the distribution of speeds is broader.
265
266
molecules in the substance all play a role. Temperature and pressure also can affect the amount of
VOlUM E 1
5
a degree of temperature. For liquid water, this is
temperature of tungsten.
I 1.8 F, you could instead change the temperature of a gram of tungsten by 108 c I 194 F.
267
Point of No Return
that transform the meat from raw to mediumrare. You can cool the steak back to 40 ' C I
104 ' F, but it will never again be raw. This transformation is what we mean when we refer to an
irreversible change.
Most cooking is about achieving such irreversible changes in a controlled way. Changes of this
kind typically occur within narrow bands of
THE TECHNOLOGY OF
Temperature (' F)
Collagen
shri nks
60
190
170
150
130
70
80
Temperature (' C)
We placed a piece of Kobe beef cheek into a differential scanning calorimeter (left) and
gradually heated it to typical cooking temperatures. Energy input per degree of heating
268
(right) rose near 63 ' CI 145 ' Fand again near 78 ' CI 170 'F, signaling the irreversible
changes in protein chemistry that transform meat from raw to cooked.
90
composition.
THE TECHNOLOGY OF
Controlling Temperatu re
Not so long ago, the mark of an expert chef lay in his ability
to control the fire and to judge how long and how close to
hold the food to it. But in this area at least, technology has
bested human expertise, and electronic instruments are
now vastly better at controlling temperature than chefs are.
A device ca lled a proportional-inte gral-derivative (PI D)
controller can determine not just the current temperature but
also the rate of warming or coo ling of its probes and the
cumulative amount of overshoot or undershoot. It then
adjusts the rate of heat input accordingly (see Controlling the
Temperature, page 2230). These devices combine high-end
temperature sensors with software programs and relays that
regulate a heating element. The name PI D refers to the way
this software makes its calcu lations.
27 0
1,000 times as much energy as in the older definition. Sometimes people capitalize Calorie to make
clear that they mean the larger unit, but often they
do not. This nonsensical custom has become so
widespread that it is impossible to fight. To avoid
misunderstanding, some people distinguish
between a "gram-calorie" and a "kilogramcalorie." A kilocalorie, meaning 1,000 calories,
always refers 1,000 of the smaller unit.
mislead.
So to clear up confusion at the outset, on one
272
in other words. But then food scientists, nutritionists, and others took to using calorie to mean the
5
measures of energy and power when cooking-as
long as you use metric units. Suppose you have a
liter of cold water at 5 c, and you want to heat it to
from
into
multiply by
erg
horsepower
watt
745.7
===
--======:
1,055.06
joule
3,600,000
=;;;;;;;;;;;o;;;;i
calorie
watt
kilocalorie/
watt
....:==:
==~
0.293071
4,186.8
second
joule
erg
BTU/hour
0.00134102
watt
f40T1 .
40WATT
U.S.A.
Alto
Power ratings on appliances and light bulbs are commonly given in watts, the fundamental
unit of power in scientific terms. A kilowatt (kW) is 1,000 watts.
273
Efficiency
Like the water bath in the preceding example,
most electrical appliances are rated in watts. The
ratings refer to the maximum amount of electricity they draw when operating, not the amount of
power they deliver during use. It's important to
Facts on Friction
274
cooker's inefficiency.
5
HEAT IN MOTION
The most important ways that frying, boiling,
dominant.
The silver teapot is a stylish but impractical solution for storing a hot beverage.
Silver conducts heat better than most
cookware. which is why the handles on
this pot are insulated with hard rubber.
Because of its high conductivity, the pot
will cool quickly. The popularity of the
silver teapot created the market for
insulating tea cozies.
Conduction in Cookware
copper pots are quite popular because of a widespread perception that they cook more efficiently.
HE AT AN D EN ERGY
277
THE HISTORY OF
aT =aVl T
()T
at
In this equation, at represents the rate at which temperature is changing with time, V 2 T is the temperature gradient in
the food, and a is the thermal diffusivity of the food (a measure of how fast heat spreads in that particular food at
a particular temperature).
The heat equation tells us that the steeper the temperature
gradient between the inside and the outside of the food, the
faster heat will flow to its interior. Our instincts tell us that,
too-but our instincts don't tell us the actual temperatures in
specific parts ofthe food at exact times. Fourier's model does.
Or rather it could if the complexity of food did not defy our
ability to model it mathematically. Solid foods typically
278
5
Conduction in Food
each shape.
center.
A potato impaled with aluminum rods cooks more quickly because the metal helps to conduct heat to the interior
of the food. This principle inspired the "fakir grill," a Modernist device named for the Near Eastern mystics who lie
on beds of nails. The analogy is imperfect. of course. because the spikes of the grill are meant to stab the overlying
food, whereas the recumbent mystics remain unscathed.
279
convection cells.
more buoyant; as they cool, their densities increase so they tend to sink.
In the kitchen, convection almost always leads
THE TECHNOLOGY OF
Cooking In Silica
Because the mathematics of heat flow is so well understood, computer programs such as COMSOL (below left)
and Mathematica (below right) can model it with terrific
accuracy-to within a fraction of a second or a fraction of
a degree. Food presents special challenges to heat-flow
models, however, because it's not usually made of uniformly
conducting materials but instead is a sloppy mixture offats,
Time=1200
282
Slice: Temperature
["q
sugars, and proteins, solids and liquids, and muscle and bone.
Nevertheless, simple models can give results that are
accurate enough to be useful. By augmenting off-the-shelf
programs with custom software, we've been able to do virtual
cooking experiments in silica that would be physically difficult
or would simply take too much time in the kitchen. The results
are highly informative-if not edible.
Boundary: Temperature ( C]
5
speed cooking for certain kinds of foods, the
bakes or boils at a given temperature. Add a circulating pump to your water bath, or stir a simmering pot of food, and you can disturb the boundary
layer and greatly hasten cooking.
To quantify just how quickly convection moves
heat from source to food, we need a measure that
takes into account the density, viscosity, and flow
velocity of the fluids involved-much as thermal
diffusivity incorporates the analogous information
for heat conduction in solids. The heat transfer
Heat transfer
coefficient
Heating method
natural convection from air
20
water bath
100-200
condensing steam
200-20,000
deep-frying
300-600
HEA T AN D ENERGY
283
Heat Rays
Every source of heat also radiates light-and vice
versa-but that light isn't always the visible kind.
In fact "heat rays" typically fall into the part of the
spectrum that lies outside the relatively narrow
band to which human eyes are sensitive. The
For more onthe effects of reflectivity in
broiling food , see page 218.
wavelengths oflight used to cook food, for example, are mostly in the microwave and infrared
range, longer than the longest wavelengths of
visible red light (hence the "infra" in infrared).
Broilers and grills cook mainly by radiation,
also called radiant heat. Both visible and infrared
radiation emanates from the heating elements or
glowing coals. Atoms in the food absorb some of
the light waves and convert the light energy into
faster motion or more energetic vibrations, and on
the macroscopic scale this is heat. How much
energy the food absorbs thus depends on how
THE PHYSICS OF
griddle instead of out into the kitchen . You don't lose any of
the intense conductive heat you want for cooking. So get out
the chrome polish. It's worth it to keep your griddle gleaming.
fortably hot.
284
5
1 minute
3 minutes
2 minutes
3Y2 minutes
What's less obvious, maybe even counterintuitive, is that objects that absorb more radiation also
phenomenon.
3! minutes
Celsius or Fahrenheit. That fourth-power relationship means that the radiant energy of an object
grows by leaps and bounds as the temperature of
Temperature ("C)
-20 0
200
400
600
Wavelength (nm)
800
1,000
200
285
Radiation differs from conduction and convection in yet another way: how it decreases over
distance. As a form of light, heat rays obey the
inverse-square law oflight, meaning that intensity
falls off as the square of the distance from a point
its importance in the kitchen. The heating elements used in grills or broilers aren't point
sources like light bulbs; instead they tend to be
_s_=x
4nr2
r-----r-----r--. .....;.:.;""-1
3r
286
THE PHYSICS OF
Steaming cool soup? Evaporation cools hot liquid, but a humid layer
quickly forms over the surface of hot soup, slowing evaporation.
Blowing across the soup moves that humid layer aside, allowing more
dry air to come into contact with the liquid. That speeds the cooling.
288
find as a solid, liquid, and gas in nearly any working kitchen: namely, water.
290
Further Reading
THE
PHYSICS
OF FO OD
('
C> <
AND
WATER
WATENRGI~ STUFF
STRA
296
ENER~\~~TE
THE
CHANG IN
300
FREEZING NG
AND MELTI
304
VAPORIZAli?~NAND314
CONDENS
IMATION
ITION
SUBLDEPOS
AND
326
WATER AS
A SOLVENT
330
WATER QUALITY
AND PURITY
335
.,,
""
6'
'!-.
THE PHYSICS
100%
WATER, WATER
(ALMOST)
EVERYWHERE
The human body is 50%-60% water,
and most of the foods we eat are
at least as "wet." Fresh produce is
commonly high in water; baked
goods and fatty foods tend to have
less. Some fruits and vegetables
contain a higher percentage of water
than is in beverages such as milk or
soda. Water exists in even the most
unlikely foods: "dry" powdered milk,
for example, still contains 3%-5%
water. Percentages given at right
are for typical samples of the foods,
uncooked where appropriate.
294
80
70
~
-c
c:
60 -
.....""::0
50
"'Oi
"'
00
c"'
"'u
Oi
c..
0%
Carrot
Cucumber
Cherry
Bread
Water: 88%
Fat: 0 .24%
Water: 95%
Fat: 0.11 %
Water: 82%
Fat: 0.2%
(whole w heat)
Water: 39%
Fat: 3%
r
100
100%
0%
Whole milk
Water: 88%
Fat: 3%
Redwine
Water: 86%
Fat: 0%
Pork loin
Water: 59%
Fat: 24%
Pork belly
Water: 37%
Fat: 53%
Walnut
Water:4%
Fat: 65%
Avocado
Water: 73%
Fat: 15%
295
WATERISSTRANGESTUFF
The properties and behavior of water are so
water-based solutions .
Take the water out of a food, and the texture
296
THE CHEMISTRY OF
Molecules of water form a jumble when in liquid form (below left). Each molecule is H20:
two hydrogen atoms (light blue) joined to one atom of oxygen (dark blue). The electrons in
the molecule are skewed more toward the oxygen atom than toward the hydrogen atoms,
so the oxygen atom is somewhat more negatively charged than the hydrogen atoms,
resulting in two electric poles like the two poles of a magnet. Ahydrogen bond forms
between two close water molecules when a (positive) hydrogen atom in one molecule is
attracted to the (negative) oxygen atom in the other. In ice, the molecules are arranged
into a lattice of hexagonal cells (bottom right) .
~
~
~ ~
~
298
THE ENER GY
OF CHA NGIN G STAT ES
Because of its anomalous properties, water is the
only chemical compound on Earth that occurs in
the natural environment in all three of the primary states of matter: solid, liquid, and gas. The states
that we have a specific name for each: "ice" (solid
the water itself; it only heats or cools its surroundings. So the heat we're talking about here is qualitatively different from the familiar, sensible heat that
3 00
u
140
"'
"'a.E
a.
E
70
"'
1-
500
1,500
1,000
2,000
2,500
3,000
6
however, measure the large quantities of energy
we have to expend or extract to make water boil,
prt>ssurl's Isuch .1s l.lnllrrnsl rll'.lr tlw bottom .111d high prt>ssur<s !such
.1s thosp in.1 pr<ssur<' cookNI tcm.u-d tlw top.
Solid lims dt>lirw.lt<' tlw bound.~ries lwtlll'l'n till' r<.llms of solid,
liquid, .llld g.1s . ..\tll'mJH'r.lturl' pr<'SSUI'l' combin.rtions lwrw.1th tlw solid
lims, tlw ph.!st's onpitlwrsid<' <anl'\ist togl'llwr-th,lt is, tlw lin<'S tr.H'l'
tiw nwlting .111d boiling points, \\'hich shift .1s tlw pr<'SSUI'l' ch.lllg<'s. ITiw
"norm,J I" frePting.llldhoilingpoints ofll.lt<'r,ltO ( .!2 l.llld 100 C
212 I al'tu.JII\' .1pp l\' only 11 lwntlw .unbi<ntprt>ssure is I b.u 1-Li psi.)
The critical point marks the region on the phase diagram where
liquid and gas become indistinguishable. ll<'l ond till' critical point.
I ill' m.lteri.ll l'\ists " ' supercritical tluidth.lt displ.l\s f,,ltuns of
both .!liquid .rnd .1 g.rs. I ik< .1 g.rs .1super..-ritic.lliluid is COill]>rl'ssihl<
.tnd t.'\p.uuh to fill ih tont.tiner. but ... ub .. t.tnce .. di .. soln in it,,.., if it
1\l'rl' liquid. llw nitic.rl point of11.ller f.1lls .lt 221 h.rr !.201 psi .mel
70) I. SII]Wr< rit i<.ll w.ltl'r is unlikelv to he lound in I he
!7~ t
kitchen. hutsupercritic.tl r.ubon dio\ide is used in industri.tl
prou.s..,es \\ ith food. l lnlike the hoi lin g .tnd free/ing point..,, tht. lriplt
.tnd critic.t l points .trP fi,ed; they do not\ .ny with pressun..
LIQUID
LIQUID
Solidus
(melting curve)
SOLID
Triple
LIQU ID
Critica l point
SUPERCRITICAl REGION
Saturation curve
GAS
ordered arrangement. Nucleation sites are therefore where phase changes begin, not only from
resists freezing so much that it can be supercooled: it can remain liquid even when chilled
3 04
the water, the more they get in the way, and the
lower the freezing point becomes. Note that the
a lot of dissolved sugar. In practice, other constraints may apply, such as how much of a sub-
I 14 op, Until
305
foods, -60
-80 c
When food is frozen at a low enough temperature, any remaining liquid in the cells will turn so
crystal. The word "glass" evokes images of windows and certain polymers, but water saturated
- 20 c I - 110 p to -4 p.
Storing food below its glass-transition temperature greatly helps to preserve its quality. Unfortunately, almost all freezers found in homes or
A freezing front moves through tuna in
these cross sections, showing clearly how
freezing takes place from the outside in.
The tissue at the very center of the fish
may never freeze completely.
3 06
6
boxcars. By the late 1940s, freezers were increasingly common home kitchen appliances in the
THE PHYSI C S OF
Water Activity
to take off.
Today, you can choose among many types of
freezers, each of which has different advantages
and disadvantages. The most common type of
home freezer uses static air to cool its contents to
about -20 c I -4 F. A commercial plate freezer
works more like Birdseye's machine and also a bit
like a frying pan in reverse: two flat plates sandwich the food and draw heat from it via a coolant
pumped through them at around -40 c I -40 p.
This approach is best for foods with uniform
shapes, such as burgers, fish fillets, and fish sticks.
Restaurants can use blast freezers, which include
a fan to increase the flow of cold air around the food
to speeds of about 2- 5 ml s (6.6-16.4 ftl s), in much
the same way that the fan in a convection oven
circulates hot air. This technique can freeze foods in
vacuum-sealed.
30 7
Crystalline solids such as ice, salt. and quartz consist of characteristic orderings of atoms or ions that are reflected in the shapes of
the macroscopic crystals. Asnowflake clearly shows the hexagonal
geometry of ice crystals (bottom image at left). Salt grains
(middle) reflect the cubic ordering of their ions. And the spiraling
tetrahedrons of vitamin Cgive rise to long, pointy obelisks (top).
308
Freshly frozen beef (left) and the same beef after two and a half months of storage in
a standard commercial freezer (right) illustrate the damaging effects of improper
handling. The stored beef is riddled with holes caused by large ice crystals, which grow
I II I
slowly in the spaces between cells. When the beef is thawed after having been stored for
months, it loses about twice as much fluid as it would have if it had been frozen for just
48 hours.
(l I
309
temperature.
a blast chiller, you simply put the food in, close the
door, and press the button. Advanced models have
sterilization.
the weight of the ice. The salt will cause the ice to
melt, thus lowering the temperature of the brine.
You must use plenty of ice-enough to equal at
least 1.5 times the mass of the food you want to
freeze, although you may need more depending on
the shape of the food and the container you use.
3 10
As soon as food is frozen by one of these methods, transfer it to a freezer for storage-ideally one
Thawing
Except for a few foods like ice cream that are eaten
frozen, most foods must be thawed before use.
3 11
6
done slowly at around refrigerator temperature to
times accurately, and it is difficult to get a temperThin foods can also be cooked at high heat
while frozen. Frozen slices of foie gras are often
readings are accurate at low temperatures (6265 oc I 145-149 F) to continue to thaw and cook.
Freezing thick foods is generally not a good
in the refrigerator.
3 13
Inside any given container at any given temperature, the pressure of a gas is directly proportional
314
VOLUME 1
going on.
Boiling
315
THE PHYSICS OF
the
1 Simmering is not boiling, although it does occurofwhen
steam form on the
3 16
Film boiling. Film boiling is the rarest of the stages be cause it only
occurs in fluid so superheated that a continuous blanket of steam
covers the entire heating surface. Because enormous amounts of heat
must be marshaled to produce film boiling, it neve r occurs in the
kitchen, with one rare exception: leid e nfrost droplets (see next page).
Photos courtesy of: John H. Lienhard IV and John H. Lienhard V ''A Heat Transfer Textbook"
4th edition, 2011, http://web.mit.edu/lienhard/www/ahtt.html
6
nucleation sites. The earliest of these bubbles
back down.
previous page).
THE PHYSICS OF
Skating on Gas
Flick a little water on a medium-hot griddle, and the water
hisses, bubbles, and boils quickly away. That's called flash
boiling. But when the griddle gets much hotter than the
boiling point of water, the droplets form small balls that
skitter around without vaporizing for as long as a minute, as
if they were on skates of shooting steam. You are watching
the Leidenfrost effect, named after Johann Gottlob Leidenfrost, a German doctor who described it in 1756.
When a drop of water hits a metal plate at or above about
200 C I 390 F, called the Leidenfrost point, the part that first
3 17
318
6
Steam
Steam is a constant presence in the kitchen, but it's
often confused with its close relative, fog. Understanding the difference can save you from serious
injury, because steam and fog can exist at very
different temperatures.
Any liquid produced by a phase transition
from the gaseous state is called a condensate; if
a condensate is in the form of droplets so tiny that
they remain suspended in the air, it's a fog, sometimes referred to as a mist or cloud, depending on
the size and dispersion of the droplets. Cooks may
call the clouds that rise above kettles and pans
"steam," but those clouds are not steam, which is
invisible; they're fog: suspended drops of liquid
water. In short, if you can see it, it's not steam
(a synonym for vapor); it's either fog or a mixture
of steam and fog.
The crucial difference for a cook is that fog can't
be any hotter than the boiling point of water-if it
were, its droplets would vaporize. Steam, in
contrast, can be superheated almost without limit
and can cause serious burns. Its invisibility only
adds to the hazard. Not only is steam typically
hotter than fog, but it also releases a terrific
amount ofheat (the heat of vaporization) when it
condenses to liquid water, which it is likely to do if
it comes in contact with your skin. In fact, almost
everything that steam comes in contact with can
be heated by condensation.
When you steam food, water vapor condenses
on the food 's surface, creating a thin liquid layer
transfer. Steaming doesn't dissolve sugars, nutrients, and other soluble components the way
boiled counterparts.
3 19
32 0
175 "C I 350 "F, for instance, and you might expect
THE PHYSICS OF
32 1
2
3
Dip the thermometer bulbs in water, then wipe the bulb that does not have a sock on it
with a paper towel to dry it.
Grasp the handle firmly. Hold the gadget well away from yo ur head and any walls
or appliances.
Swing the thermometers aboutthe handle vigorously for aboutl Y, min.
Reading times vary, so follow the manufacturer's instru ctions.
Use the chart provided by the manufacturer (not shown) to determine the relative
humidity. On some psychrometers, th e chart is printed directly on the handl e.
322
6
HOW TO Read a Psychrometric Chart
1
2
Find the nearest wet-bulb temperature line (the lighter blue lines that
slope downward from left to right) and follow itto the left to read the
the wet-bulb temperature.
Drop straight down to the temperature axis to read the dew point.
Relative humidity(%)
0.20
....
......
0
"'"'ca
E 0.15
....
Q)
-:;;
Wet-bulb temperature (0 C)
:::
......
0
"'"'ca
s
0
-~
0 .10
30
30
40
so
60
70
80
90
100
323
6
striking. On a summer day, when high humidity
suppresses evaporative cooling, the surface of food
because the air is not only cold, it's also dry. That's
why, in cold seasons, it's a good idea to wrap your
325
SUBLIM ATION
AND DEPOSI TION
Melting and freezing, steam and fog, dew and
humidity-these are all relatively familiar phenomena involving phase changes in water. The
interior.
Critical point
SUPERCRITICAL
FLUID
mation or deposition in action, you have undoubtedly witnessed their effects, perhaps more often
dealt to frozen foods by dehydration and subsequent oxidation. Deposition, on the other hand, is
how the same water vapor that came out of your
freezer-burned food winds up as thick deposits of
ice and frost that cover the insides of your freezer,
if it's not a self-defrosting model.
In a high school chemistry class or at a rock
concert, you may have seen the "smoke" that pours
off dry ice (solid carbon dioxide). That smoke is
evidence the solid has sub\imed to a chilly gas that
cools the surrounding air enough to cause a fog of
condensed water to form. You can't see the C0 2
gas itself, but the fog is quite noticeable, especially
if you put the dry ice in a bucket of water. Before
modern fog machines came into use, that's how
special effects designers on scary movies and rock
concerts made the "smoke." (You could always tell
The main practical implication of this phenomenon is that cold, dry air alone can dehydrate
food. The ice crystals in frozen food can sublime,
leading to freezer burn. You can protect most
foods from this withered-looking condition-or
ground.)
326
Regular ice sublimes, too, but at colder temperatures than dry ice does. If you have a frost-free
freezer, you may have noticed that your ice cubes
rapidly, then put it under vacuum to speed sublimation, and you have freeze-drying.
You might associate freeze-dried food mainly
with instant coffee, the trail chow consumed by
backpackers, and astronaut food. But it's much
more useful than that. Freeze-drying came upon
the scene in the 1960s as something of a technological marvel, but believe it or not, the Peruvian
Incas used to freeze-dry their crops by taking
them to the top ofMachu Picchu, where both the
temperature and the atmospheric pressure were
low. Modern freeze-drying can preserve the
appearance, flavor, aroma, and nutritional value of
food, which can then be stored nearly indefinitely
at room temperature. With its moisture gone, both
microbial growth and chemical spoilage reactions
in the food are substantially slowed.
In the freeze-drying process, the temperature of
the food is first brought below the triple point of
water, where only ice and vapor can exist, so that
encourages sublimation.
Cold temperatures and dehydration are useful
separately for preserving food, and together, they
can make a powerful combination. Freeze food
oo
o-r~6~
o -r~4~o~
o~
- 2ro~o_,__o~--~2~
- 4ro~o-r~
, rSUPERCRITICAL FLUID
10 3
...,
8"'
QJ
:;
Critical point
10 2
make frost in your freezer. You've seen the snowflakes it has grown in the clouds.
In all these cases, ice has been deposited
Temperature {"F)
10
SOLID
10
GAS
"-
10
-200
100
200
300
Temperature {c )
Carbon Dioxide
Triple point: - 57 C I -71 F at 5.2 bar I 75 psi
Critical point: 31 oc I 88 oF at 74 bar I 1,073 psi
328
VOLUME 1
WATER AS A SOLVENT
We all know that certain solid materials, like salt
and sugar, dissolve in water. The scientific term for
a substance into which other substances dissolve is
solvent_The substance that dissolves into the
solvent is called the solute, and the homogeneous
sometimes oil.
330
even very hot water. Add more salt than that and
water at SO c
I 122 F.
less than the sum of the volumes of the salt and the
I 212 p, When
I 284 p, the sugar
33 1
20
60
Temperature ( F)
180
140
100
90%
-.::: 5,000
-~
80%
V>
V>
"'E
V>
'-.
.!:9 2,000
70%
Sugar
~
:::J
0V>
.'
60%
:.0
0
V>
V>
:::J
0V'l
50% $"'
1,000
.'
500
----
40% :.0
:::J
0V'l
30%
Salt
- 20
20
80
40
60
0
Temperature ( C)
excess solute generally precipitates out by reverting to the solid state as crystals. Initially rather
small, these crystals of the solute can grow to be
quite large, especially if you allow solvent evaporation to continue in an uncovered container.
It's easy to make a supersaturated solution of
sugar in water, simply by cooling a saturated
solution or allowing it to evaporate. You can make
those huge sugar crystals called rock candy in this
way by adding thousands of crystallization nuclei
(in the form of several suspended strings) and
letting the setup stand around, evaporating away,
for a couple of weeks.
When cooks blend two liquids together, they
often think of that as mixing. Sometimes, however,
what they are really doing is making a solution. As
when dissolving a solid in a liquid, the polarities of
the components often govern what happens.
Most people know that alcohol (ethanol) is
332
'-.
c0
"
0V>
220
10,000
100
120
140
Tiny Bubbles
Champagne-and fish-are possible because
333
6
WATER QUALITY AND PURITY
Pure water is an excellent solvent-indeed, it's
Distilled water makes a fine substitute for deionized water, but it's more expensive.
use. But the quality and purity of tap water can have
combi ovens.
335
Lemon segment
, I
/
j l'
.~
'i