GB2608350A - Coffee capsule - Google Patents

Abstract

A roast and ground coffee composition for use in a beverage capsule. When measured with a dry laser diffraction method, the coffee composition has a volume mean dimension (D4,3) of 290-390 microns, preferably 320-360 microns, and between 11-19.5% of fines less than 90 microns, preferably between 16-18%. When measured with a wet laser diffraction method in water, the coffee composition has less than 8% of ultra-fines (less than 10 microns), preferably less than 2%. Preferably, the coffee is decaffeinated. Preferably, the beans have a moisture content 1-8 wt%, more preferably 4-6 wt%. Preferably, the beans are roasted to a colour between 6-14 Lange, preferably 7-9 Lang. A beverage capsule containing the composition is also claimed. Preferably, the capsule comprises a filter and 5-5.6g of coffee. A method of producing the composition is disclosed. The coffee composition can be used to produce a beverage more quickly.

Description

Coffee Capsule The present invention relates to a ground coffee composition for use in a beverage capsule, a method of making the composition and the use thereof. In particular, the invention relates to a coffee composition which avoids a high pressure build-up during brewing, while achieving a full extraction and providing a desirable coffee beverage.

Espresso-type beverages are short concentrated drinks with a strong coffee taste that are very popular with consumers. It is known to produce espresso beverages from capsules using high pressure home brewing machines. These machines typically involve the use of impermeable cartridges and injection means to allow the provision of pressures in excess of 9 bars.

EP1882432 discloses a method of decreasing the delivery time of an espresso-type beverage from such a high-pressure machine. The technique involves minimising the presence of fines in the ground coffee to affect the percolation rate through the bed of coffee. Fines are defined in EP1882432 as those particles having a diameter of less than 88.91 microns when measured by the Malvern laser diffraction method in butanol. The aim of EP1882432 is to increase the rate at which a fixed volume of beverage medium can flow through a cartridge and relies upon a puncture resistant membrane to increase the pressure in the coffee bed to result in a faster extraction.

EP1566127 relates to a beverage preparation system for the provision of short and long coffee beverages. In some embodiments of EP1566127 the flow rate through two capsules are predetermined by the capsule contents to result in the provision of short and long coffee beverages. The use of a coarser coffee grind and/or a higher fill weight is used to achieve a faster flow rate through an otherwise identical capsule.

EP2570032 relates to the provision of a coffee filter pad which can be used to provide a short beverage in low pressure coffee machine. The filter pad contains a bimodal coffee distribution having a large amount of fine material. This allows the formation of significant back-pressure, resulting in a low final beverage volume when used in a fixed-time dispensing coffee machine.

There remains a need for providing a good extractions yield in a fast dispensing time, without compromising on the coffee extraction levels, especially in lower pressure preparation systems. It is an object of the present invention to address this problem, tackle the disadvantages associated with the prior art, or at least provide a commercially useful alternative thereto.

Accordingly, in a first aspect there is provided a roast and ground coffee composition for use in a beverage capsule, wherein, when measured with a dry laser diffraction method, the roast and ground coffee composition has a volume mean dimension of from 290 to 390 microns and a level of fines less than 90 microns of from 11 to 19.5%, and wherein, when measured with a wet laser diffraction method in water, the roast and ground coffee composition has a level of ultra-fine material of less than 10 microns of less than 8%.

In the following passages different aspects/embodiments are defined in more detail. Each aspect/embodiment so defined may be combined with any other aspect/embodiment or aspects/embodiments unless clearly indicated to the contrary.

In particular, any feature indicated as being preferred or advantageous may be combined with any other feature or features indicated as being preferred or advantageous.

The present invention relates to a roast and ground coffee composition. Roast and ground coffee compositions are well known in the art for use in capsules in coffee beverage machines. In use, hot water is typically added to the coffee to thereby extract flavour components into an aqueous medium. The hot flavoured water is then dispensed into a beverage receptacle for a consumer. Coffee beans are typically Robusta or Arabica beans or a blend thereof. The coffee beans may be decaffeinated before roasting if desired.

The coffee composition is for use in a beverage capsule. Beverage capsules are well known in the art and there are a range of capsules available. It will be understood that by the term "capsule" as used herein is meant any capsule, cartridge, container, or receptacle which contains one or more beverage ingredients in the manner described. The cartridge may be rigid, semi-rigid or flexible. Suitable materials that may be used are conventional and well known in the art. An inlet surface of the capsule may be selected to be pierceable by a water injection means. Such capsules tend to be water impermeable with a seal covering the outlet surface that is removable just before use or that ruptures (or is pierced) during the dispensing process.

The capsule holds the composition in a beverage machine so that the aqueous medium can be used to extract the coffee. While the composition is of use in all beverage machines, it is particularly of use for lower pressure beverage machines (such as ones which supply the aqueous medium at from 1-8 Bar), since these cannot cope so well with a significant build-up of pressure. High pressure machines typically operate at a pressure in excess of 8 bar.

The particle size of the roast and ground coffee plays an important role in determining the extraction and flavour of the beverage produced. As will be appreciated, the amount of coffee solids which can be obtained from a sample increases with a finer average grind size. This is apparent from the strong flavour of Turkish coffee (very finely ground) and results from the increased surface to volume ratio of small particles.

Accordingly, in order to increase the yield of solids achievable in a given extraction time, it would be expected that a finer coffee grind should be employed. However, when the size of the coffee is decreased, the amount of fine material increases and the coffee bed becomes more compacted and more greatly inhibits the flow through the bed. While this can be overcome to some extent by increasing the pressure, beverage machines have limitations in the pressure they can produce. Accordingly, to decrease the build-up of pressure it would be expected to use a coarser particle size grind.

As explained below, the inventors have found that the provision of a specific coffee composition allows the provision of a full flavoured beverage without an undesirable build-up of pressure. Specifically, the inventors have discovered that the pressure is most strongly affected by those ultra-fine particles having a size of less than 10 microns and that reducing the amount of these particles reduces the build-up of pressure. They have further found that these ultra-fine particles do not contribute to the extraction yield to the extent expected, such that a reduction in the ultra-fine particles does not compromise the final beverage. After careful study, the inventors have found various preparation techniques which minimise the formation of the ultrafine particles.

Specifically, the invention relies on the provision of a roast and ground coffee composition which has a volume mean dimension of from 290 to 390 microns and a level of fines less than 90 microns of from 11 to 19.5%, wherein, when measured with a dry laser diffraction method, and wherein, when measured with a wet laser diffraction method in water, the roast and ground coffee composition has a level of ultra-fine material of less than 10 microns of less than 8%.

Laser diffraction methods are well known for measuring the particle size distribution of particles in a ground coffee composition. There are two main techniques used for these measurements: "dry" and "wet". Dry relies on a gravity fed dispersion of the particles through the diffraction device, whereas wet techniques rely upon the use of a solvent for the dispersion. Different solvents may lead to different results, particularly in view of the effect of the solvent on coffee oils.

The present inventors have found that for coffee the particle size distributions obtained by dry techniques and wet techniques are not quite the same. Specifically, a water dispersion measurement shows significantly more fine and ultra-fine material than a dry technique. Without wishing to be bound by theory, it is considered that in the dry sample the fine material is adhered by electrostatic forces into clusters or adhered to larger particles. Alternatively, these smaller particles may be adhered with coffee oils. Accordingly, while dry measurement techniques are advantageous for quick and easy sample measurements, it is required to perform wet analysis, such as in water, for observing ultra-fine material levels.

Wet and dry laser diffraction methods are well known in the art and the following specific machine settings are provided by way of example only. A person skilled in the art would be able to configure suitable measurements based on this exemplary set of settings and apparatus.

For the determination of particle size distribution using a wet laser diffraction method, a Malvern Mastersizer 2000 with a Hydro Mu as a dispersion system may be used. 800 ml of de ionised water is added into a 1L glass beaker and the background of the water is measured in the instrument. For sample preparation, a coffee sample is mixed thoroughly to ensure sample homogeneity before weighing. Then 0.5g of coffee is weighed in a small beaker to which is added 0.01% of non-ionic surfactant (titron X) and 1 ml of de ionised water. The sample is manually mixed before transferring the entire sample into a 1 L beaker containing 800m1 of deionized water. The samples are then place on the dispersion unit and consistently mixed with a speed of 2000rpm throughout the duration of measurement. To start the measurement, sonication is applied to the samples using 5 amps for 30 seconds to break the big sample aggregates. The sample is left to rest for 3 min and then measurement was performed. Once the sample is added it is ensured that there is a laser obscuration of 10-20% then sample can be measured.

Suitable system settings include an RI of 1.53; analysis mode -general purpose; sensitivity normal. Measurement time is 5 secs and background time 15 seconds.

All measurements should be repeated 3 times.

For the determination of particle size distribution using a dry laser diffraction method, a SympaTec HELOS/KR laser diffraction system with RODOS/M disperser and VIBRI dry powder feeder can be used. The primary pressure is set at 3 bar, which allows for a 95 -105 mbar depression to be established in the RODOS/M dispersion line. The R6 lens is chosen and a Reference run is performed for 20 seconds in order to record and eliminate optical background information. A homogenous intake of 30g of Roast and Ground sample is poured in the VIBRI funnel. A Normal run is then performed with a VIBRI funnel gap of 8mm at 100% feed rate. The acquisition starts when the optical concentration exceeds 1.5% and stops after 5 seconds below 1.2%. Volume-based density and cumulative distributions are drawn using the FraunhOfer-Enhanced Evaluation (FREE), which allows for the calculation of the median particle size (x50). The operation should be repeated three times for each sample.

As noted above, the inventors have discovered that the pressure build-up during brewing in a coffee machine is most strongly affected by those ultra-fine particles having a size of less than 10microns, but that this does not affect the extraction yield.

The "extraction yield" refers to the strength of the extract and is defined as the weight of total solids in the liquid extract divided by the total weight of starting coffee ingredients in the capsule (e.g., roast and ground coffee). This value is typically expressed as a percentage.

Without wishing to be bound by theory, it is considered that this ultrafine material is in part the burned cell wall material from the coffee. This is because the sizes of pores in coffee beans are from 30 to 50 microns. This means that particles having a mean size of 300 microns typically contain whole cell portions, whereas pieces of less than 10 microns must necessarily be formed in part of fragments of the cell walls. It is noted that material of around 2 microns is likely to include, in part, oil particles. Accordingly, the finest material fragments which are formed during grinding are not those portions of the coffee fragments associated with extractable coffee material. As a result, the ultrafines do not make a significant contribution to the extractable solids.

The particle size values such as the volume mean dimension and the levels of fines and ultra-fines can be determined from the laser diffraction machines output. Such techniques are well known in the art and further details are provided in the Examples. The particle size distribution of the ground coffee can be measured using the laser diffraction software to determine the range of particle sizes and any peaks. 15 The volume mean dimension is also known as the D4.3.

Preferably the coffee is decaffeinated. The present inventors were in particular seeking to provide a decaffeinated roast and ground coffee composition for use in an existing capsule for a beverage preparation machine. However, they were surprised to discover that, when substituting decaffeinated coffee beans into the processing steps for their standard caffeinated coffee beans, it not provide the consistent brew performance necessary for commercial sale. That is, the straight substitution of a decaffeinated coffee composition having the same particle size did not achieve a brew weight of a minimum 95% of brew cycles dispensing more than 30g, and an average of more than 36g, and an average brew time between 15-30s.

Indeed, with the initial decaffeinated coffee preparations there was a high average back-pressure, which frequently exceeded the maximum limits set by the control measures within the system, causing the brew to end prematurely. This led to a wide range of brew times and drink weights; drinks of an acceptable brew weight were more likely to require an unacceptably long brew time, and more acceptable brew times were less likely to achieve the desired brew weight.

The inventors investigated the coffee and the preparation steps used to prepare the composition for the coffee beverage. They were surprised to find that the decaffeination process appeared to have had an effect on the coffee composition. Further investigation determined that the changes could be replicated with caffeinated and decaffeinated coffee grinds and that the changes could be manipulated to solve the problems of miss-brewing and to provide an ideal coffee composition for use in a beverage capsule.

The inventors found that when they decaffeinated ground coffee under similar conditions to the standard caffeinated coffee grind, the VMD and level of fines smaller than 88.91 microns would be substantially the same. However, on closer inspection it was surprisingly found that the level of fine material having a particle size of below 10 microns was higher in the decaffeinated coffee. Accordingly, it is especially preferred for decaffeinated coffee compositions that the level of ultra-fine material is reduced to less than 8%, preferably by using the techniques disclosed herein.

Preferably the roast and ground coffee composition has a volume mean dimension when measured with a dry laser diffraction method of from 320 to 360 microns.

Preferably the roast and ground coffee composition has a level of fines less than 90 microns, when measured with a dry laser diffraction method, of from 16 to 18%.

Preferably, when measured with a wet laser diffraction method in water, the roast and ground coffee composition has a level of ultra-fine material of less than 10 microns of less than 5%, preferably less than 2%.

According to a further aspect there is provided a beverage capsule for use in a beverage preparation machine, the capsule containing a roast and ground coffee composition, wherein, when measured with a dry laser diffraction method, the roast and ground coffee composition has a volume mean dimension of from 290 to 390 microns and a level of fines less than 90 microns of from 11 to 19.5%, and wherein, when measured with a wet laser diffraction method in water, the roast and ground coffee composition has a level of ultra-fine material of less than 10 microns of less than 5%.

As will be appreciated, the capsule preferably contains the roast and ground coffee composition described herein. Preferably the fill weight of the roast and ground coffee composition in the capsule is from 4.75g to 6g, preferably from 5 to 5.6g. The inventors found that surprisingly lower capsule fill weights, which might be expected to reduce back-pressure made brew performance worse. It is suspected that the gas within the increased head space becomes trapped and compressed within the coffee bed, reducing the available flow area and increasing resistance and back-pressure.

Preferably the capsule is sealed before use.

Preferably the capsule comprises a filter for retaining the roast and ground coffee composition during dispensing of a beverage.

According to a further aspect there is provided a method of preparing a roast and ground coffee composition for use in a beverage capsule, the method comprising: roasting coffee beans to produce roasted coffee beans having a roast colour of between 6 and 14 Lange, quenching the roasted coffee beans with water to provide roasted coffee beans having a moisture content of from 1 to 8wrio, and grinding the quenched roasted coffee beans to a volume mean dimension of from 290 to 390 microns and a level of fines less than 90 microns of from 11 to 19.5%, when measured with a dry laser diffraction method.

Roasting techniques are well known in the art. The coffee beans are roasted to a roast colour of between 6 and 14 Lange. This is a colour scale whereby lower numbers are darker and indicate a longer roast.

Quenching is performed to cool the beans quickly after roasting to preserve the flavours. The quenching may be performed by the controlled addition of water which is absorbed into the means to provide a desired final moisture content. The beans may be allowed to equilibrate for a time after the water is added.

Grinding techniques are well known in the art and devices for performing the grinding or milling include roller mills, cutter mill and ball mills. Roller mills are most preferred and may comprise a plurality of pairs of rollers, between which the coffee beans are crushed. The settings may be fine-tuned to target a desired VMD of the ground coffee. It is preferable for the coffee beans to be kept chilled or cooled during grinding to minimise any undesirable scorching of the beans.

The inventors have found that the use of a darker roast colour and a more moist coffee before grinding leads to a reduced level of ultra-fine material. Without wishing to be bound by theory, it is considered that the darker roast leads to a more readily fragmented material, while the greater moisture increases the final fragment size.

That is, the bean quickly breaks into small (but not ultrafine) pieces. This is a surprise because the choice of a darker roast colour would be expected to simply make the coffee more brittle and hence generate larger quantities of fines. By contrast, light roast colour and low moisture coffee generated the worst brew performance.

As will be appreciated, the method is preferably for producing the roast and ground coffee composition as described herein.

Preferably the coffee beans are roasted to produce roasted coffee beans having a 5 roast colour of between 7 and 9 Lange.

Preferably the roasted coffee beans are quenched with water to provide roasted coffee beans having a moisture content of from 4 to 6wr/o. This level of moisture was more likely to achieve the desired low levels of ultrafine particles.

According to a further aspect there is provided a method of preparing a beverage, the method comprising introducing a beverage capsule as described herein into a beverage preparation machine, whereby an aqueous medium is passed under pressure through the capsule to extract the roast and ground coffee and to produce a coffee beverage therefrom.

As will be appreciated, the final beverage may be characterised by the volume of water that passes through the coffee and into the final beverage. Therefore, the amount of coffee in a capsule is important to ensure that there are sufficient coffee solids in the final beverage. The coffee solids can also be increased by reducing the flow rate to allow for a longer extraction time, although this is not preferred in a home beverage machine due to consumer patience.

The present inventors have sought to provide an authentic coffee-shop-style coffee beverage for consumers to make at home. Such beverages include short beverages, such as espresso and ristretto, and longer beverages. An espresso is an aromatic flavourful short coffee drink with a crema layer and significant in-cup body and mouth feel. Coffee shop Espresso beverages are typically 50 -70 ml volume, have 2 -6 wt % soluble solids and have a 3 -6 mm layer of "crema". The crema preferably fully covers the coffee brew surface and persists for at least 1, preferably 2 minutes. A ristretto is typically a smaller espresso beverage having a volume of typically 30 -50 ml. Longer beverages have a volume of at least 110m1.

The term "short coffee" beverage as used herein refers to a coffee beverage having a volume of from 25 to 75m1, more preferably from 30 to 70m1 and most preferably either an espresso (50 -70m1, more preferably 55 to 65m1, and most preferably about 60m1) or a ristretto (30 -50m1, more preferably 35 to 45m1, and most preferably about 40m1). In contrast, a normal or standard coffee volume has a volume of around 110m1 or greater. These values are the total volume produced in a single cycle intended for a single cup of beverage.

According to a further aspect there is provided the use of roast and ground coffee having a reduced level of ultrafine material less than 10 microns, when measured with a wet laser diffraction method in water, to produce a coffee beverage more 15 quickly.

The use is preferably is a beverage preparation system with two beverage capsules, each for use to prepare coffee beverages, wherein one of the capsules contains roast and ground coffee having a reduced level of ultrafine material less than 10 microns, when measured with a wet laser diffraction method in water, compared to the other, to produce a coffee beverage more quickly. Preferably the coffee in each capsule has a volume mean dimension within 10% of each other, preferably within 5%, and most preferably both fall within the range of from 290 to 390 microns. Preferably one of the capsules contains less than 8% ultrafine coffee, as described herein, and the other contains more than 8%.

The claimed solution improves brew performance and consistency by reducing the brew and purge pressure significantly compared to conventional coffee preparations. The solution provided herein is surprising for several reasons. The principle change relates to the particle size distribution, which is finer than currently used in most non-decaffeinated products i.e. a lower VMD and a greater percentage of particles less than 90pm. Finer coffee typically results in higher back-pressures, however, it appears this particular combination of VMD and percentage of finer particles results in a more favourable arrangement which reduces hydrodynamic resistance. Initial attempts to improve the specification tested the effect of more coarse coffee (higher VMD and fewer particles <90pm) but brew performance was equally poor.

Non-limiting embodiments of the present disclosure will now be described, by way of example only, with reference to the accompanying drawings, in which: Figure 1 shows a flow chart of the method steps involved in preparing a composition as described herein.

Figure 2 shows a graph of the brew pressure against the level of fines (less than 90 microns) for "dark dry" and "dark moist" roasted coffee beans.

Figure 3 shows a graph of the brew pressure against the level of ultra-fines (less than 10 microns) for "dark dry" and "dark moist" roasted coffee beans.

Figure 4 shows a graph of the brew pressure against the level of fines (less than 90 microns) for "light moist" and "dark moist" roasted coffee beans.

Figure 5 shows a graph of the brew pressure against the level of ultra-fines (less than 10 microns) for "light moist" and "dark moist" roasted coffee beans.

In Figure 1 the steps are: A: Decaffeinating green beans B: Roasting coffee beans to a roast colour of between 6 and 14 Lange; C: Quenching the roasted coffee beans with water to provide roasted coffee beans having a moisture content of from 1 to 8wr/o; D: Grinding the quenched roasted coffee beans to a volume mean dimension of from 290 to 390 microns and a level of fines less than 90 microns of from 11 to 19.5%, when measured with a dry laser diffraction method; E: Filling the ground beans into a beverage capsule. 5 The disclosure will now be further illustrated in the following non-limiting examples.

Examples

The following examples are demonstrated by but are not limited to decaffeinated coffee of 100% C2 Brazil decaffeinated with super critical CO2.

* All coffee samples were roasted on a Neotec roaster * Ground using a roller grinder and densified/compacted * PSD was measured on Helos dry RODOS disperser.

* Roast colour was measured in Lange.

* Moisture was measured with Infra-red equipment * All samples were packed in a capsule at 5.3g (+/-0.3g) fill weight Samples were prepared as follows: Sample Blend PSD: Roast Moisture VMD(im)/particles<90um Colour 1 Regular* 460pm/11% 9La 2.5% (current espresso blend espresso 3

specification)

2 Decaffeinated 480pm/10.3% 9La 2.5% (current coffee blend espresso

specification)

3 Regular 520/8% 9La 2.5% (coarse espresso blend PSD) 3 4 Decaffeinated 580pm/8.6% 9La 2.5% (coarse coffee blend PSD) Regular 400pm/14.3% 12La 5% (finer PSD) commercial R&G blend 6 Decaffeinated 330-380pm/11.5- 6La 5% (finer PSD) coffee blend 14.5% ular: Refers to all coffee blends that has NOT been throuah the decaffeinat *Reg on process Number of brews performed per sample * Sample 1: 2000 brews done on 20 on-demand machines * Sample 2: 1830 brews done on 20 on-demand machines * Sample 3: 2000 brews done on 20 on-demand machines * Sample 4: 160 brews done on 2 on-demands machines * Sample 5: 12 brews on 2 on-demand machines * Sample 6: 860 brews done on 9 on-demand coffee machines Samples 7 to 22 = 100% C2 Brazil decaffeinated with super critical CO2 were prepared as follows:

Table 2:

Sample PSD Roast Colour Roast time Moisture 7 1 6La 90s 5% 8 2 6La 90s 5% 9 1 6La 90s 1.5% 2 6La 90s 1.5% 11 1 6La 360s 5% 12 2 6La 360s 5% 13 1 6La 360s 1.5% 14 2 6La 3605 1.5% 1 11La 90s 5% 16 2 11La 90s 5% 17 1 11La 90s 1.5% 18 2 11La 90s 1.5% 19 1 11La 360s 5% 2 11La 360s 5% 21 1 11La 360s 1.5% 22 2 11La 360s 1.5% *PSD 1 was characterised as follow: VMD range=300-340pm, particles <90pm= 13.5-15.5% *PSD 2 was characterised as follow: VMD range=370-435pm, particles <90pm= 1113.5% Brewed on 4 on-demand coffee machines Number of repetitions per samples= 60 brews (30 on 2 machine types) Influence of PSD on brew performance on decaffeinated coffee and a comparison versus regular coffee was made: a decaf coffee behaves differently from a regular 10 coffee.

Example 1: Decaf coffee (sample 6) with the most preferred ranges of PSD, moisture, colour. The finer ground decaf coffee shows an improved brew performance versus the other decaf samples (sample 2 and 4 in Table 1) with coarser grind size demonstrating that decaf coffee performs better at 330-380pm VMD range.

Comparative example 1: Decaf coffee vs regular coffee at current espresso PSD (sample 1 vs 2). The graph below (Figure 1) shows the performance of decaf coffee 20 vs a regular coffee at espresso PSD range (440+1-40 pm and 9-12% <90 pm). This shows that a decaf coffee does not perform acceptably at current regular PSD and that a decaf coffee has to be ground at different PSD vs current regular espresso blends to get an acceptable brew performance.

Indeed, at commercial regular coffee PSD (-current espresso PSD as above), decaf coffee performance is unacceptable based on the definition of good performance with long brew times, high amount of misbrews (21%) and low brew weight average delivery.

Comparative example 2: decaf coffee vs non-decaf coffee at coarser PSD (samples 3 vs 4). The graph below show that increasing VMD (going coarser) improves brew performance of regular coffee, especially brew time, but no improvement is observed for decaf coffee (same amount of misbrews to espresso PSD, no brew time improvement). This confirms that a decaf coffee behaves very differently to regular coffee.

Comparative example 3: non-decaf coffee performance does not seem to improve at finer PSD like a decaf coffee does (samples 5 vs 6). Standard coffee at finer PSD range performs poorly compared to the decaf coffee at the same PSD range and coarser regular coffee PSD.

Indeed, the graphs below show that a regular coffee blend (sample 5) does not brew within acceptable performance criteria (high average brew time and unacceptably low average brew weight delivery) at finer PSD and that going finer in PSD for regular coffee does not improve performance. The decaffeinated blend however, shows a very good performance when going finer (low brew time average and above acceptable brew weight average delivery resulting in a good flow through capsule).

Influence of roast colour, roasting time, moisture on brew performance of decaf 30 coffee.

Example 2

The analysis of coffee preparation samples 7 to 22 showed the following: Roast colour = a darker roast colour increases brew weight, reduces brew time and therefore improves the flow through the capsule.

Roast time = a longer roast increases brew weight, reduces brew time and therefore improves the flow through the capsule Moisture = a higher moisture content increases brew weight, reduces brew time and therefore improves the flow through the capsule Flow rate is calculated as [(brew weight)/(brew time)]. Consequently, a higher brew weight (for a constant brew time) or short/fast brew time (for a constant brew weight) will increase the flow rate. A higher flow rate suggests a better flow through the capsules and is therefore the desired outcome.

Further examples

C2 Brazil Arabica beans were dark roasted (-4.8 lange) over 6 minutes (slow roast); one batch at high moisture (5.1%) and another at low (<1%).

These were ground in the MPE Roller grinder at settings 1, 3, 5, 8 and 10.

Fill weights of 7g, 8g and 9g were used, and 10 discs of each were brewed in a T65 brewer using barcode 29761 (long non-crema drink) in CT filter discs.

Generally, low moisture beans give a finer grind. This effect becomes more evident at the finer grinder settings. Additionally, low moisture beans give much more ultrafines for a given percentage of fines. Low moisture dark coffee generates higher peak pressures (by 0.1-0.2 bar) cf high moisture dark coffee. Low moisture medium roast coffee does not behave significantly differently to high moisture medium coffee. Its levels of ultrafines are not affected in the same way as the dark coffee.

The low moisture dark coffee generates similar peak pressures to all the previously 5 tested medium roast coffee.

Laser diffraction The apparatus used for the measurements is discussed above.

The diffraction of a laser light beam is dependent on the size of particles passing through it. A suitable detector & computer system convert the beam diffraction pattern into a particle size distribution. For the dry measurements a Sympatec Helos laser diffraction particle size measurement system can be used with a Rodos dry dispersion unit for powders and computer interface plus hardware to run the data logging & calculation software.

The procedure and settings used were as recommended by the manufacturer for the type and size range of product being measured. The sample size poured into the 20 dispersing system was around 10 -20g. A lens with a focal length of 1000 mm, suitable for particle sizes between 9 -1759 microns was used.

Logging, calculation & presentation of the data are carried out by the software provided by the manufacturer. This is set to calculate & present values for "03"-a normalised particle volume distribution -and its first derivative, q3 -a particle volume distribution density. For the purposes of this calculation, the software is set to assume the particles of roast & ground coffee are spherical. This is considered a reasonable assumption from close inspection (by microscopy) of the ground coffee powder. The values for VMD and fines can be obtained directly from the outputted information.

Tapped density Tapped bulk density is the sample weight in grams per unit volume (g/I) under tapped conditions.

A sample is poured into a graduated cylinder which is tapped a defined number of times. The compacted volume and weight are recorded and the density is calculated based on this. Measurement is carried out using a Tap Volumeter (e.g. Stampfvolumeter STAV 2003, J. Engelsmann AG, Germany), 250 ml graduated glass cylinder, round base, suitable for tap volumeter equipment, Powder funnel, Balance (minimum accuracy 0.01g).

The method involves the following steps: 1. Place the retaining ring from the Volumeter over the empty graduated cylinder and tear on the balance, 2. Using the powder funnel, pour between 230-240 ml of sample into the cylinder. Allow the sample to fall freely into the cylinder. Avoid any vibration during the filling process, 3. After removing the powder funnel weigh the cylinder with the sample and note the weight, 4. Set the counter of the volumeter for 86 strokes, 5. Start the machine. After the set number of strokes has been completed read off the compacted volume.

DT = (M / VT) *1000 where: DT = Tapped Bulk Density [g/L] M = Weight of sample [g] VT = Compacted sample volume [ml] Unless otherwise stated herein, all percentages are by volume.

Although preferred embodiments of the disclosure have been described herein in detail, it will be understood by those skilled in the art that variations may be made thereto without departing from the scope of the disclosure or of the appended claims.

The invention will now be described further with reference to the following numbered clauses: 1. A roast and ground coffee composition for use in a beverage capsule, wherein, when measured with a dry laser diffraction method, the roast and ground coffee composition has a volume mean dimension of from 290 to 390 microns and a level of fines less than 90 microns of from 11 to 19.5%, and wherein, when measured with a wet laser diffraction method in water, the roast and ground coffee composition has a level of ultra-fine material of less than 10 microns of less than 8%.

2. The roast and ground coffee composition according to claim 1, wherein the coffee is decaffeinated.

3. The roast and ground coffee composition according to claim 1 or claim 2, wherein the roast and ground coffee composition has a volume mean dimension when measured with a dry laser diffraction method of from 320 to 360 microns.

4. The roast and ground coffee composition according to any of the preceding claims, wherein the roast and ground coffee composition has a level of fines less than 90 microns, when measured with a dry laser diffraction method, of from 16 to 18%.

5. The roast and ground coffee composition according to any of the preceding claims, wherein when measured with a wet laser diffraction method in water, the roast and ground coffee composition has a level of ultra-fine material of less than 10 microns of less than 5%, preferably less than 2%.

6. A beverage capsule for use in a beverage preparation machine, the capsule containing a roast and ground coffee composition, wherein, when measured with a dry laser diffraction method, the roast and ground coffee composition has a volume mean dimension of from 290 to 390 microns and a level of fines less than 90 microns of from 11 to 19.5%, and wherein, when measured with a wet laser diffraction method in water, the roast and ground coffee composition has a level of ultra-fine material of less than 10 microns of less than 5%.

7. The beverage capsule according to claim 6, wherein the coffee composition is according to any of claims 1 to 5.

8. The beverage capsule according to claim 6 or claim 7, wherein the capsule is sealed before use and comprises a filter for retaining the roast and ground coffee composition during dispensing of a beverage.

9. The beverage capsule according to any of claims 6 to 8, wherein the fill weight of the roast and ground coffee composition in the capsule is from 4.75g to 6g, preferably from 5 to 5.6g.

10. A method of preparing a roast and ground coffee composition for use in a beverage capsule, the method comprising: roasting coffee beans to produce roasted coffee beans having a roast colour of between 6 and 14 Lange, quenching the roasted coffee beans with water to provide roasted coffee beans having a moisture content of from 1 to 8wt%, and grinding the quenched roasted coffee beans to a volume mean dimension of from 290 to 390 microns and a level of fines less than 90 microns of from 11 to 19.5%, when measured with a dry laser diffraction method.

11. The method according to claim 10, wherein the method is for producing the roast and ground coffee composition according to any of claims 1 to 5.

12. The method according to claim 10 or claim 11, wherein the coffee beans are roasted to produce roasted coffee beans having a roast colour of between 7 and 9 Lange and/or wherein the roasted coffee beans are quenched with water to provide roasted coffee beans having a moisture content of from 4 to 6wt%.

13. A method of preparing a beverage, the method comprising introducing a beverage capsule according to and of claims 6 to 9 into a beverage preparation machine, whereby an aqueous medium is passed under pressure through the capsule to extract the roast and ground coffee and to produce a coffee beverage therefrom.

14. Use of roast and ground coffee having a reduced level of ultrafine material less than 10 microns, when measured with a wet laser diffraction method in water, to produce a coffee beverage more quickly.

15. The use according to claim 14 in a beverage preparation system with two beverage capsules, each beverage capsule for use in the beverage preparation system to prepare coffee beverages, wherein one of the capsules contains roast and ground coffee having a reduced level of ultrafine material less than 10 microns, when measured with a wet laser diffraction method in water, compared to the other, to produce a coffee beverage more quickly.

Claims (15)

1. Claims: 1. A roast and ground coffee composition for use in a beverage capsule, wherein, when measured with a dry laser diffraction method, the roast and 5 ground coffee composition has a volume mean dimension of from 290 to 390 microns and a level of fines less than 90 microns of from 11 to 19.5%, and wherein, when measured with a wet laser diffraction method in water, the roast and ground coffee composition has a level of ultra-fine material of less than 10 microns of less than 8%.
2. 2. The roast and ground coffee composition according to claim 1, wherein the coffee is decaffeinated.
3. 3. The roast and ground coffee composition according to claim 1 or claim 2, 15 wherein the roast and ground coffee composition has a volume mean dimension when measured with a dry laser diffraction method of from 320 to 360 microns.
4. 4. The roast and ground coffee composition according to any of the preceding claims, wherein the roast and ground coffee composition has a level of fines less than 90 microns, when measured with a dry laser diffraction method, of from 16 to 18%.
5. 5. The roast and ground coffee composition according to any of the preceding claims, wherein when measured with a wet laser diffraction method in water, the roast and ground coffee composition has a level of ultra-fine material of less than 10 microns of less than 5%.
6. 6. The roast and ground coffee composition according to claim 5, wherein when measured with a wet laser diffraction method in water, the roast and ground coffee composition has a level of ultra-fine material of less than 10 microns of less than 2%.
7. 7. The roast and ground coffee composition according to any preceding claim, wherein the roasted coffee beans have a moisture content of from 1 to 8wV/0.
8. 8. The roast and ground coffee composition according to claim 7, wherein the 5 roasted coffee beans have a moisture content of from 4 to 6wt%.
9. 9. The roast and ground coffee composition according to any preceding claim, wherein the roasted coffee beans have a roast colour of between 6 and 14 Lange.
10. 10. The roast and ground coffee composition according to any preceding claim, wherein the roasted coffee beans have a roast colour of between 7 and 9 Lange.
11. 11. A beverage capsule for use in a beverage preparation machine, the capsule containing a roast and ground coffee composition, wherein, when measured with a dry laser diffraction method, the roast and ground coffee composition has a volume mean dimension of from 290 to 390 microns and a level of fines less than 90 microns of from 11 to 19.5%, and wherein, when measured with a wet laser diffraction method in water, the roast and ground coffee composition has a level of ultra-fine material of less than 10 microns of less than 5%.
12. 12. The beverage capsule according to claim 11, wherein the coffee composition is according to any of claims 1 to 10.
13. 13. The beverage capsule according to claim 11 or claim 12, wherein the capsule is sealed before use and comprises a filter for retaining the roast and ground coffee composition during dispensing of a beverage.
14. 14. The beverage capsule according to any of claims 11 to 13, wherein the fill weight of the roast and ground coffee composition in the capsule is from 4.75g to 6g.
15. 15. The beverage capsule according to claim 14, wherein the fill weight of the roast and ground coffee composition in the capsule is from 5 to 5.6g.