WO2016077360A1

WO2016077360A1 - Low-pressure cooking method and cookware vessel adapted for the same

Info

Publication number: WO2016077360A1
Application number: PCT/US2015/059973
Authority: WO
Inventors: Edward S. Sherman; Stanley Kin Sui Cheng; Hing Hang Homer Cheung; Chun Wing Wong; Kam Yuen Li
Original assignee: Meyer Intellectual Properties Ltd.
Priority date: 2014-11-14
Filing date: 2015-11-10
Publication date: 2016-05-19

Abstract

Food stuffs are cooked at precise temperatures, which are optionally below 100 °C, in a vessel that is evacuated to exclude air, in which low pressure steam replaces the air. When a sufficient quantity of air is excluded and replaced with water vapor, the temperature of vapor is accurately measured inside the vessel below the lid to control the temperatures within about 1° C. Air is preferably excluded via a controlled heated process for a relatively short period of time at high temperature to generate steam, the temperature is lowered to condense water vapor upon which the lid will sealingly engage the rim of the vessel, forming a partial vacuum in the cooking vessel.

Description

Specification for an International (PCT) Patent Application for:

Low-Pressure Cooking Method and Cookware Vessel Adapted for the Same Cross Reference to Related Applications

[0001 ] The present application claims the benefit of priority to the US Non- Provisional patent no. 14/542,436, which was filed on Nov. 14, 2014, and is incorporated herein by reference.

Background of Invention

[0002] The present invention relates to methods of cooking food, and particularly cooking food under controlled temperature conditions, and suitable cookware vessels and equipment for this method.

[0003] Prior methods of controlled cooking include the so-called Sous Vide process, in which foodstuffs are sealed in plastic bags, and the sealed bags are then immersed in a temperature controlled water bath. The water bath temperature is specific to the foodstuff intended to be cooked, and in the case of animal proteins is sufficient denature some of the proteins, and depending on the nature of the animal proteins may also be sufficient to dissolve collagen, and/or affect other chemical conversions of foodstuff components to a precise level. However, since the internal food temperature will never exceed the water bath temperature, the cooking time must be sufficient for the interior of the food to reach this temperature. Cooks use either guidelines or experience to determine the cooking time, and frequently the desired cooking temperature. Alternatively, needlelike temperature probes can be inserted through foam seal in plastic bags to actually measure the internal temperature of the food during cooking, and hence terminate cooking when the entirety of the food has reached the desired temperature. Such termination is preferred in the case of fish and other proteins that would seriously degrade upon excess maintenance at this temperature, in contrast to other proteins sources such as what are generally considered inferior cuts of meat, that are generally tough due to the high collagen content. In such cases, the cooking time is extended for hours, if not days, to at least partially dissolve a large percentage of such collagen to tenderize the meat. [0004] While the use of plastic bags to hold the foodstuffs can be helpful for

flavoring some foods, as well as for immediately cooling and freezing the cooked food within the bag, this adds expense and complications for the general consumer. In particular, it should be noted that it is difficult to vacuum seal bags that contain fluid, unless very expensive equipment is used, and these processes are time-consuming. The vacuum sealing process increases food preparation time as compared to other cooking methods, despite the fact that the cook is free to do other things in the kitchen during the entire cooking, due to the constant temperature of the water bath, which largely precludes overcooking many types of food. [0005] However, such water baths with precise temperature control are expensive, consume considerable counter space and in many cases also continuously fill the kitchen with water vapor. Further, cooking is delayed by the time it takes to fill and heat the water bath.

[0006] Another method of cooking food at low temperature, i.e. below the

atmospheric pressure boiling point of water (100° C or 212°F) is in a reduced pressure chamber. US Pat. Appl. No. 2003/0038131 Al discloses such a methods in which a lidded microwave transparent container is heated in a microwave oven. The container lid has a gasket to seal with the container, and a central one way valve to release steam. The foodstuffs are heated by microwave so they release water, which along with added water turns to steam at high microwave powers. As the one way valve is designed to limit air return when the steam condenses to water, a vacuum is formed in the container. While a relatively short initial heating period can be used to expel air with expanding steam, the foodstuffs would already be directly cooked to some degree by the initial microwave exposure. Hence, for delicate or thin foodstuffs, the benefits of low temperature cooking would still not be obtainable. The application also failed to teach or disclosure how to maintain a subsequent temperature or pressure within the vessel. [0007] US Pat. No.'s 5,318,792; 5,767,487; 5,662,959 and 6,152,024 disclose various oven configurations for cooking in low pressure steam atmospheres. The ovens are sealed with gaskets, and in fluid communication with an external vacuum pump. The foodstuffs are held above an internally heated water bath. Similar to Sous Vide cooking, the water bath temperature is measured, so that at an equilibrium condition the food would be exposed to the surrounding water vapor of the same temperature. The equipment disclosed in these patents is intended for commercial use, but also had inherent limitations for consumer use. These ovens, being large, are cumbersome and subject to breakdown from moving parts as well as the exposure of heaters to water or water vapor.

[0008] US Pat. No. 4,381,438 discloses a cooking apparatus that deploys an induction heating base to heat a cookware vessel. The power to the induction cooking bases is controlled in response to a sensor located in the lid of the vessel. The sensor detects steam, and in response to steam or steam temperature, reduces the heating power. The disclosure fails to provide an indication of the accuracy of the method and the stability of the temperature in the vessel.

It is therefore general object of the invention to overcome the above-noted deficiencies of Sous Vide cooking, in particular to eliminate evacuated sealed plastic bags, but rather use cookware vessels also suitable for general purposes.

[001 0] It is also an object of the invention to provide a cooking apparatus and method that is capable of cooking various large sized, thick and/or irregularly shaped foods that cooks should not seal in evacuated plastic bags for Sous Vide cooking, as they would have extremely long cooking time, and could pose food safety issues.

[001 1 ] It is also an object of the invention to provide a methods to cook such large size, thick or irregularly shaped foods without sealing in a vacuum bags at low temperatures, which is below the boiling point of water, in an accelerated mode in comparison to the long terms required in Sous Vide cooking.

[001 2] It is another object of the invention to provide these benefits and advances in a cooking method that can uses ordinary heat sources in a consumer kitchen, or at least a specialty heating source that is compatible with other methods of cooking.

[001 3] The above and other objects, effects, features, and advantages of the present invention will become more apparent from the following description of the embodiments thereof taken in conjunction with the accompanying drawings

Summary of Invention

In the present invention, the first object is achieved by providing a cooking assembly comprising a heating base having an upper surface for supporting a cookware vessel, in contact with a heater element, and a controller that is responsive to energize the heater element, a cookware vessel having a bottom portion adapted to be supported by the upper surface of the heating base, substantially upright sidewalls extending upward there from to terminate at a rim, the sidewalls encircling said bottom portion to form an interior portion capable of retaining a fluid, a lid adapted with a gasket to engage said cookware vessel at the rim thereof to form a vacuum seal therewith, a thermal probe that enters an interior portion of the vessel and is in signal

communication with the programmable controller, a pump in fluid communication with the vessel to reduce the partial pressure of air in the cookware vessel to 0.3 Bar and less, wherein the programmable controller is operative first energize the pump to reduce the partial pressure of air in the vessel to 0.3 Bar and less and then to energize and de-energize the heater to maintain a pre-determined temperature entered into the programmable controller in response to the temperature measured by the thermal probe.

Another object of the invention is achieved by providing a cooking assembly comprising a heating base having an upper surface for supporting a cookware vessel, in contact with a heater element, and a controller that is responsive to energize the heater element, a cookware vessel having a bottom portion adapted to be supported by the upper surface of the heating base, substantially upright sidewalls extending upward there from to terminate at a rim, the sidewalls encircling said bottom portion to form an interior portion capable of retaining a fluid, a lid adapted with a gasket to engage said cookware vessel at the rim thereof to form a vacuum seal therewith, a thermal probe that enters an interior portion of the vessel and is in signal communication with the programmable controller, a side handle connected to an exterior sidewall of the vessel wherein the side handle provides a means for routing a wired connection of the thermal probe to the programmable controller, wherein the programmable controller is operative to energize and de-energize the heater to maintain a pre-determined temperature entered into the programmable controller in response to the temperature measured by the thermal probe.

[001 6] Another object of the invention is achieved by providing a cooking assembly comprising: a vessel having a curvilinear shaped exterior bottom, uprights sides that surround the bottom to extend upward to a rim, a lid adapted with a gasket to engage said cookware vessel at the rim thereof to form a vacuum seal therewith, a thermal probe that enters the interior of the vessel, a heater base adapted to receive and support the curvilinear shaped bottom, including a heater element therein having a curvilinear shape that conform to the curvilinear shaped exterior bottom of the vessel, and a programmable controller to modulate power to the heater base to heat the vessel is accordance with an output of the thermal probe.

[001 7] Another object of the invention is achieved by providing a cooking assembly comprising a heating base having an upper surface for supporting a cookware vessel, in contact with a heater element, and a controller that is responsive to energize the heater element, a cookware vessel having a bottom portion adapted to be supported by the upper surface of the heating base, substantially upright sidewalls extending upward there from to terminate at a rim, the sidewalls encircling said bottom portion to form an interior portion capable of retaining a fluid, a lid adapted with a gasket to engage said cookware vessel at the rim thereof to form a vacuum seal therewith, a thermal probe having a means to variably extend into the interior of the vessel for penetration into foodstuffs therein that is in signal communication with the heater base.

[001 8] Another object of the invention is achieved by providing a cooking vessel assembly having an outer cookware vessel that is microware transparent having a bottom portion, substantially upright sidewalls extending upward there from to terminate at an outer rim, the sidewalls encircling said bottom portion to form an interior portion capable of retaining a fluid, a lid adapted with a gasket to engage said outer cookware vessel at the outer rim thereof to form a vacuum seal therewith, an inner cookware vessel that is at least one of microwave absorbing and microwave reflective, having a bottom portion, substantially upright sidewalls extending upward there from to terminate at an inner rim, wherein the inner cookware vessel is adapted for being seated within the interior portion of the outer cookware vessel and not interfering with the sealed engagement of the lid with the outer rim to form a vacuum, at least one of the lid and the outer vessel having a sealable penetration for receiving a thermal probe sealed connection therewith.

Another object of the invention is achieved by providing a cooking assembly comprising a heating base having an upper surface for supporting a cookware vessel, in contact with a heater element, and a controller that is responsive to energize the heater element, a cookware vessel having a bottom portion adapted to be supported by the upper surface of the heating base, substantially upright sidewalls extending upward there from to terminate at a rim, the sidewalls encircling said bottom portion to form an interior portion capable of retaining a fluid, a lid adapted with a gasket to engage said cookware vessel at the rim thereof to form a vacuum seal therewith, a thermal probe that enters an interior portion of the vessel and is in signal communication with the programmable controller via a transmitter, wherein the programmable controller is operative to energize and de-energize the heater to maintain a pre-determined temperature entered into the programmable controller in response to the temperature measured by the thermal probe after the pressure is reduced to 0.3 Bar or less.

A second aspect of the invention is characterized by the gasket being operative to be urged downward by the lid when the vessel is evacuated so that the visible portion thereof above the vessel rim is disposed below the vessel rim after evacuation. Another aspect of the invention is characterized by the gasket having an F shape and the sidewall portion of the vessel sidewall below the rim has a curvilinear portion that contacts multiple portions of the F shaped gasket when a vacuum is formed in the interior of the vessel.

Another aspect of the invention is characterized by the heating element being attached to an exterior bottom of the vessel and is connected to receive power from the heating base via a de-mating connection having a first connector on an upper surface of the heating base.

Another aspect of the invention is characterized by the lid being connected to the vessel via a hinge and the side handle connected to an exterior sidewall of the vessel supports the hinge and the thermal probe that enters an interior portion of the vessel and is connected by a wired connection routed through the hinge and handle.

Another aspect of the invention is characterized by the vessel further comprising a pouring spout that wraps around an exterior portion of the vessel sidewall opposite the handle but below the rim of the vessel to avoid interference with the gasket sealing the lid at the vessel rim.

Another aspect of the invention is characterized by the handle and/or heating element having a de-mating connection to the heating base for signal and power wiring respectively

Another aspect of the invention is characterized by the lid being adapted to maintain at least one of an at least partial vacuum and a pressure greater than atmospheric pressure in the interior portion of the vessel.

The above and other objects, effects, features, and advantages of the present invention will become more apparent from the following description of the embodiments thereof taken in conjunction with the accompanying drawings. Brief Description of Drawings

[0028] FIG. 1 is a cross-sectional elevation view of the cooking vessel apparatus suitable for low-pressure steam cooking being heated by an induction burner, wherein the lid includes a means to measure the temperature of the vessel contents and communicate with the induction burner for precise temperature control.

[0029] FIG. 2 is a flow chart illustrating the steps in the cooking process using the vessel and lid sensor of FIG. 1.

[0030] FIG. 3 is a block diagram of the thermal control system for the apparatus of

FIG. 1.

FIG. 4 is a schematic diagram of the temporal variation of temperature and pressure in the vessel of FIG. 1 resulting from a first mode of operation according to the flow chart in FIG. 2.

FIG. 5 is a schematic diagram showing the application of power to achieve a consistent cooking temperature, T3, during time t3 in the control regime portion of FIG. 3.

FIG. 6 A is a cross-sectional elevation view of an alternative cooking vessel with a preferred lid gasket, whereas FIG. 6B is a enlarged cross-sectional elevation view of the gasket and a portion of the lid of FIG. 6A.

FIG. 7A-C compares the temperature variation within the vessel of FIG. 6A at different levels of replacement of air with water vapor during and between the transition from a first control temperature of 158 °F to control at 140° F.

FIG. 9 A and 9B compare the temperature variation in maintaining a steady state temperature of 120 F that corresponds with and without air replacement according to the process of FIG. 1- 4. [0036] FIG. lOA-C compares the temperature variation in maintaining a series of steady state temperature at 0.08 Bar according to the process of FIG. 4.

[0037] FIG. 11 A-B are cross-sectional views of the gasket and a portion of the vessel lid.

FIG. 12A is a cross-section of the gasket and a corresponding portion of the lid disposed on the vessel rim in a vented state whereas FIG. 12B illustrates the distortion of the gasket and the descent of the lid toward the vessel in the evacuated state.

FIG. 13 is a cross-section elevation view of the lid handle in FIG.12 in which the thermal sensor and gasket are replaced by a valve that is operative to vent to the vessel and release a vacuum formed therein.

FIG. 14A is a cross-sectional elevation view of the valve in FIG. 13, with FIG. 14B being an orthogonal is a cross-sectional elevation view thereof to show the wider portion of the valve stem and the feet, whereas FIG. 14C is an exterior elevation of the valve corresponding to the same orientation as FIG. 14A; FIG. 14D is a cross-sectional elevation view of the ring that secures the handle to the lid; FIG. 14E is a cross-sectional elevation view of the handle and FIG. 14F is a corresponding scale cross-sectional elevation view of the assembled handle, ring and valve attached to the abutting lid portion with the valve in the closed position.

FIG. 15A is a perspective exterior assembly diagram of the handle of FIG. 12- 13, before attachment to the lid and FIG. 15B is a perspective exterior view of the handle in FIG. 12 and 13 with the valve closed, whereas FIG. 15C shows a perspective view thereof with the valve closed.

FIG. 16A is a cross-sectional elevation view of another embodiment of the cooking apparatus suitable for low-pressure steam cooking and cooking under elevated pressure in which the steam is hotter than 100° C (212° F), whereas FIG. 16B is a cross-sectional elevation of an alternative thermal sensor and vacuum formation means.

[0043] FIG. 17 is a cross-sectional elevation view of another embodiment of the

cooking apparatus suitable for low-pressure steam cooking in which the vessel containing the raw food, or food to be warmed is within another vacuum vessel.

[0044] FIG. 18 is a cross-sectional elevation view of another embodiment of the

cooking apparatus suitable for low-pressure steam cooking being heated by a surrounding temperature controlled oven. [0045] FIG. 19 is a timing diagram for the transmission of signal by two different thermal sensors in close proximity each associated with a different vessel to control the heating source associated with the vessel.

[0046] FIG. 20 is a schematic diagram of the temporal variation of temperature in the vessel of FIG. lor 6 resulting from another mode of operation according to the flow chart in FIG. 2.

[0047] FIG. 21 is a cross-sectional elevation view of an alternative embodiment of the cooking vessel apparatus suitable for low-pressure steam cooking being heated by an external heat source, wherein the lid includes a means to measure the temperature of the vessel contents and communicate with the heat source for precise temperature control in which the vessel is evacuated by an external means.

FIG. 22 is an enlarged partial cross-sectional elevation view of a portion of another alternative embodiment of the cooking vessel apparatus suitable for low-pressure steam cooking being heated by an external heat source illustrating a means to measure the temperature of the vessel contents, communicate with the heat source for precise temperature control and evacuate the vessel. FIG. 23 is an enlarged partial cross-sectional elevation view of a portion of another alternative embodiment of the cooking vessel apparatus suitable for low-pressure steam cooking being heated by an external heat source illustrating an alternative means to measure the temperature of the vessel contents, communicate with the heat source for precise temperature control and evacuate the vessel which is connected to the heating source base.

FIG. 24 is an enlarged partial cross-sectional elevation view of a portion of another alternative embodiment of the cooking vessel apparatus suitable for low-pressure steam cooking being heated by an external heat source illustrating another alternative means to measure the temperature of the vessel contents, communicate with the heat source for precise temperature control and evacuate the vessel which is connected to the heating source base.

Fig. 25A is a cross-sectional elevation view of a portion of an external heat source for heating the cooking vessel in the various embodiments having a depression for storing and optionally recharging any of the previously disclosed thermal sensor embodiment that are detachable from the vessel lid in which FIG. 25B is a top plan view illustrating the section line A-A corresponding to the section location in FIG. 25 A.

FIG. 26 is a cross-sectional elevation of an alternative embodiment of the cookware vessel showing alternative embodiment of additional thermal probes.

FIG. 27 A is a cross sectional elevation of another embodiment of a thermal probe intended to indicate the penetration of a food via entry from the lid after the lid is placed on the vessel, and FIG. 27B illustrates the actuation of the indicator.

FIG. 28 is a cross-sectional elevation view of another alternative embodiment of the cooking vessel apparatus suitable for low-pressure steam cooking being heated by an external heat source. [0055] FIG. 29 is a cross-sectional elevation view of another alternative embodiment of the cooking vessel apparatus suitable for low-pressure steam cooking being heated by an external heat source, with alternative means for connecting various thermal sensors to the power controller in the heating source. [0056] FIG. 30 is a cross-sectional elevation view of another alternative embodiment of the cooking vessel apparatus suitable for low-pressure steam cooking having an attached heat element, with alternative means for connecting various thermal sensors and the heat source to the power source and power controller in a support base. [0057] FIG. 31 is a cross-sectional elevation view of another alternative embodiment of the cooking vessel apparatus suitable for low-pressure steam cooking being heated by an external heat source, with alternative means for connecting various thermal sensors and a vacuum to the power supplies, controller in the heating source and the controller of the power to the heater and vacuum pump associated with the vessel.

[0058] FIG. 32 is a cross-sectional elevation view of another alternative embodiment of the cooking vessel apparatus suitable for low-pressure steam cooking that is particularly adapted for a microwave oven.

Detailed Description [0059] Referring to FIG. 1- 33, wherein like reference numerals refer to like

components in the various views, there is illustrated therein a new and improved cookware vessel assembly for low pressure steam cooking, generally denominated 1000 herein.

[0060] The method and apparatus disclosed below allow a variety of foods to be cooked at an optimum temperature, as well as stages of different temperature, which in the more preferred embodiments, enables exceptionally precise control of temperature to achieve a consistent degree of cooking completeness throughout a wide variety of foods.

[0061 ] These results are achieved by discovery of the exceptional temperature

uniformity that can be achieved when a vessel is sealed with a very low partial pressure of air, in which the air is replaced by water vapor in a stable equilibrium. This result is most preferably achieved in the configuration of FIG. 1 in which the vessel is heated from below. The cooking temperatures can be well below the boiling point of water at atmospheric pressure, which is 212° F (100°C). [0062] Commercial cooking establishments have cooked food at temperatures lower than 212 °F by sealing food in an evacuated bag that is placed in a constant temperature water bath. The evacuated bag is held in the bath for a time sufficient for the center of the food to reach the water bath temperature. This method of cooking is best known by the generic name of Sous Vide cooking, which translated from French means - under vacuum-. Sous Vide cooking, while widely practiced in commercial kitchens, is not in common consumer use.

[0063] In accordance with the present invention, it should be first understood that low-pressure steam cooking is process in which foodstuffs need not be sealed in plastic bags before cooking, as they are immersed in a temperature controlled low-pressure steam environment. As the steam does not strip the food of flavor components or vitamins, it is not necessary to seal food and plastic bags or other containers, although such sealing can be practiced when it is desired to exchange or provide flavoring components from a liquid or aqueous media, such as liquid fat or olive oil, or from a poaching liquid such as court bullion.

[0064] It has been discovered that with the inventive apparatus all the benefits of

Sous Vide cooking can be obtaining without the above limitations associated with it. Such limitations include among others, cooking only foodstuffs in parcels that are relatively small and flat, extended cooking times, as well as an undesirable extraction of fluids from animal proteins into the surroundings of the evacuated plastic bags. Accordingly, the following disclosure will explain how these disadvantages our overcome with the inventive equipment and process.

[0065] FIG. 1 illustrates a preferred embodiment of a cooking apparatus 1000

adapted for the inventive cooking method, which includes a vessel 110 that is capable of containing a fluid that has a rim 113 at the terminating upper edge of the sidewalls 112 that surround the sealed bottom 115. The vessel 110 is disposed on a horizontal heating source 400, which is preferably planar, or abuts at least a portion of the exterior bottom of the vessel 110. A lid 200 is adapted for substantially vacuum tight engagement with the rim 113 of the vessel via a gasket 250 that engages and co-seals with the periphery 214 of the lid 200. The lid 200 provides at least one vessel venting means 111. A temperature measurement means 300 is preferably disposed in the lid 200, but can be configured in alternative locations. The temperature measurement is used to control the output of the heater 400 for a desired combination of power, time and temperature to achieve the benefits and advantages summarized above, as discussed in more detail below. [0066] It has been discovered that as the low pressure steam has excellent circulation within the vessel, the cooking temperature can be accurately monitored and controlled using a thermal probe 322 that descends into the vessel 110 interior by only a few mm's via a portal in the lid 200, as shown in FIG. 4-6. In other words, such a thermal sensor probe constantly monitors the surrounding vapor temperature. Since its accuracy will depend on the efficiency of heat transfer between the probe and its surrounding to reach a thermal equilibrium quickly, it is working at its best in a partially vacuum pot when surrounded mostly by saturated low pressure steam after most of the air has been driven out of the pot. The same portal 205 for inserting the thermal probe 322 is preferably the vacuum vent means. As a preferred method to form the low pressure steam is by heating or boiling a very small quantity of water to displace air, it has been discovered that a sufficient vacuum for low pressure steam cooking can be obtaining by without an independent pressure measurement, or a separate air pump. [0068] It has also been discovered that a sufficient time period for such boiling can be derived based on the time it takes to heat the water so that the thermal probe is close to the boiling point of water. The time period required to form a low pressure steam atmosphere for cooking is about 50% of the heating time required to bring the measured vapor temperature to 94 °C (201°F) from room temperature minus 60 second. The time t2 is preferably calculated from tl by subtracting 60 seconds, then dividing the result by 2 minutes.

[0069] Hence, in a more preferred embodiment of the invention, the thermal probe measurement is submitted to the controller 430, which logs the time (tl) required to reach 94 ⁰ C. If the heating time is less than 60 seconds , the heat source 460, preferably an induction burner, will stop heating immediately.

[0070] This control scheme has worked under a range of conditions including,

variations in pot sizes from 16 cm to 24 cm diameter, using both stainless steel and aluminum cookware bodies, as well as starting the process with between about 30 ml to about 200 ml of additional water in the vessel, independent of food content. The lack of food content was successfully simulated by evaluating this control method with by 200 ml of ice sealed in a bag. In all cases, a vacuum level of at least about 0.3 Bar was achieved on further cooling down to 30 °C ambient temperature.

[0071 ] Under these conditions, a sufficient vacuum to seal the lid 117 under its own weight to the rim 113 via gasket 250 is achieved when the water vapor temperature drops below 95°C. Therefore, low pressure steam cooking can be carried out satisfactorily for cooking temperature up to 190°F (about 87 °C) without the need to cool below the desired cooking temperature before reheating taking place. In the inventive methods, using various 3-4 liter vessels with an attached induction cookware base and commercial induction heaters, boiling occurs in 60-300 sec. depends on size of pot and water/food content, Subsequent cooling, that is lack of heating for 240-1500 sec. though somewhat dependent on the vessel dimension and water/food content, allows the water vapor temperature to be reduced to the desired cooking temperature with temperature range as low as 50° C. Thereafter, subsequent heating to a higher cooking temperature requires only about 30-90 sec.

Hence, further aspects of the invention include the process for cooking in and holding the steam temperature within at least about 1° F (1.8 ⁰ C), and more preferably 1° C of the desired cooking temperature.

In the preferred embodiment of FIG. 1, the temperature measurement means 300 deploys a thermal probe 322 that descends downward through a sealed penetration 205 in lid 200 to measure the temperature in the vessel 110 interior in proximity to the rim 113 and the interior of the lid 200. This otherwise sealed penetration 205 is optionally a vessel venting means when the thermal probe 300 is detached from the lid 200. As shown in FIG. 5, 11 and 15, the temperature measurement means 300 is also preferably a removable knob or assembly nested in a recess in the annular or knob like handle 215 that is used for gripping and lifting the lid 200. It is also preferable that the vessel lid 117 is dome shaped to provide strength, and more preferably is folded about the lower rim thereof to increase the stiffness at the gasket engaging or accepting portion.

Alternatively, the temperature measurement means 300 is optionally an external thermal sensor, in thermal communication with the interior of the vessel via a sidewall rather that the lid. This internal temperature measurement means 120 thermal probe, such as a thermal couple, thermistor, thermopile and infrared temperature detector and the like. Temperature measurement means can also be a thermal probe attached to the sidewall of a vessel, and more preferably is a thermal probe disposed in thermal communication with the interior wall of a double wall vessel, in which the external signal communication from the thermal probe can optionally be through wiring that extends through or is connected at the exterior sidewall. Alternatively, the vessel 110 may be equipped with a signal feed through for a thermal probe such as a thermocouple, or thermistor which is directly inserted into the foodstuff 101.

It should also be understood that the temperature control means is optionally resident in the thermal probe, the heating means, or another device, and in addition to the preferred control scheme disclosed below, is optionally a proportional-integral, derivative controller (PID) in signal communication the controller of the output to the heating means. In addition the heating means is preferably an induction burner base, but is also optionally an infrared heating base, a heated metal plate, ring or coil or a gas flame. Alternatively, the heating means can be an oven, as shown in FIG. 17. In FIG. 18, as the heated interior of the oven surrounds the vessel 110, the vessel and its interior will eventually reach the oven temperature of the oven. Heating means or source with a thermal mass, such as heating rings and hot plates, are less preferred as it is more difficult to precisely control the temperature as disclosed in preferred embodiments.

As shown in the block diagram of FIG. 3, the preferred thermal measurement means 300 deploys a thermal probe 322 that is in signal communication with an attached signal processor 310 and transmitter 320, which then sends a signal, preferably a wireless signal (such as an RF signal) 305, to a receiver 420 of the heater 400. This signal is communicated to a preferably

programmable controller 430 of the heater 400 to modulate the power output from the power supply/source 410 to heater element 460, which provides a predetermined power and/or temperature temporal profile to achieve the desired cooking results. The thermal measurement means 300 preferably contains a power supply 301, transmitter 320 and necessary signal processing unit, such as a microprocessor or controller 310 to convert the temperate probe output to a wireless transmission, such as an RF signal. Controller 430 is preferably programmable in the sense that is has either a series of programs or operation modes that can be selected by the user, with the option of the user entering in parameters, such as times and temperature cycles to effect a program of operation, as well as preset modes, that the controller operational in accord with a previously entered program that can be update an changed in the future. The selection of the programs and the entry of a parameters can use any conventional user interface and control panel, such as switches, remote controls, and the uploading of programs from other devices.

[0077] An RF signal receiver 420 of the heater 400 can be integrated with the

machine housing for the controller 430, power supply/source 410 and induction heating coils 460. In such a case it is also preferable than the RF signal is carried at a frequency (typically 315MHz) much higher than the induction field frequency (typically 70kHz) when the heater element 460 is induction coils. In this case, only common commercial precautions are required to achieve the needed signal to noise ratio, even in the presence of the RF noise created by the induction burner. Further, it is preferable to deploy an encoding scheme to reduce the read error rate, however, an error rate of one out of 10 will not affect the cooking process in the preferred process control method of the induction burner controller 400. An aspect of a currently preferred means to reduce error rates is also the coding scheme for sending temperature information twice, each time with a predetermined delay period in between so that if one of them is successfully decoded, then the updated temperature information will be obtained. It should be understood that controller 430 is preferably a programmable controller that is operative to provide different cooking times, temperatures and time-temperature profiles adapted to the foodstuff to be cooked.

[0078] It is also preferable to conserve the life of the battery or power source 301 by limiting temperature information transmission by controller 330. In the case of wireless RF transmission of the temperature measurement by the sensor 300 to the heater 400, the transmission need not be continuous from tl to t3, particularly during tl, unless the vessel is manually evacuated, it is not necessary to transmit temperature until about 90°C. It is desired to measure and transmit the temperature to the controller 430 in the later part of the cooling process (t2) where a few seconds are needed to cool the content of the pot by 0.1 °C; and in the re-heating cycle as most of the time the temperature is changing very slowly.

[0079] Every time controller 430 receives a temperature measurement, it is the most updated temperature of the sensor, being only delayed by the processing time. Hence, in preferred embodiments in which heating times are controlled in response to the temperature changes, then the time of data receipt is logged by the processor 430 as is it needed for making decision, i.e. the induction or other thermal heating member base controller 430 will use the receiving time of each signal or signal packet as a reference. Hence, power can also be conserved by limiting the time of such transmissions in relation to the temperature stability. More specifically, it is preferable that the temperature measurement controller 330 is operative to initiate transmission by 310 at least as frequently as every second if difference between consecutive readings is greater than 0.5 °C, every two seconds if difference greater than 0.25 ⁰ C and every four seconds if difference not greater than 0.125 °C. In this scheme the number of transmission needed is greatly reduced to reduce power consumption by half.

[0080] In the cooking method, the foodstuff 1 is optionally supported above the

interior bottom of the vessel 110 by a plate, tray or rack 5. The plate, tray or rack 5 can be used to raise the foodstuff 1 , above the water 2 that covers the bottom 115 of the vessel 110. Pressure will reduce once steam replaces at least some of the interior air in the vessel 110, provided the gasket 250 or another member acts as a one way valve, so that as the steam cools and condenses, rather than air being sucked back into the vessel, the condensation of steam to water forms a partial vacuum in the vessel. The lid 200 has a sufficient weight in proportion to the pliability of the gasket 250 so that as the pressure reduction (from the condensation of heated water vapor) reduces the pressure within the interior of the vessel 110, the gasket 250 sealingly engages both the rim 113 of the vessel 110 and the lower periphery 214 of the lid 110.

Though the absolute vacuum level during subsequent cooking will depend on the temperature, it is highly desirable to displace enough air so that the partial pressure of any air in the sealed and partially evacuated vessel is much less that the partial pressure of water vapor, and more preferable the air has a partial pressure of less than about 0.3 Bar, as measured when the vessel 110 is cooled entirely to room temperature.

In a preferred embodiment of the method, the low-pressure steam

environment is formed in a cookware vessel 110 via the steps in the flow chart of FIG. 2. The first step is providing a vessel 110 (step 101) capable of retaining fluid and introducing foodstuffs in the vessel 110 (step 102), as well as an aqueous fluid (step 103) before sealing the vessel 110 with the lid 120 (step 104) such as by engagement with the rim 113 thereof with the gasket 250 provided about the lid periphery 214. In a preferred mode or embodiment, the bottom 115 of the vessel 110 is placed on a heater 460, and the heater is energized (105) for a time sufficient to raise the internal temperature of the fluid to Tl, which is then held for a time t2 prior to de-energizing the heater 460 in step 106. It should be appreciate that the above method is applicable to the various embodiments of the cookware vessel, lid and sensors disclosed herein.

The heating in step 105 is intended to convert a sufficient quantity of water vapor to replace the atmospheric content of the vessel 110. Then after step

106, the interior of the vessel 110 will cool to a 2nd lower temperature (T2 or T3') than the first temperature (Tl), wherein the condensation of the water vapor within the vessel 110 causes an internal reduction pressure sufficient to engage the lid 200 to seal with the rim 113 of the vessel 110. Then in step

107, the vessel is maintained at a at least one 2nd temperature (T3) for a predetermined amount of time (t3), which is preferably is counted as starting from the end of t2.

[0084] It should be appreciated for delicate foods that would cook quickly, it is

desired that tl is as brief as possible, to minimize the total exposure to the highest temperature T_max, and rapidly reach the cooking temperature T3 or T3'. This is best accomplished by using a vessel 110 that is comparable to the size of the food being cooked, that is without extreme excess volume around the food, and avoiding adding excess fluid. While the fluid must be sufficient in volume to expel the air, this quantity is relatively small given the more that 1000: 1 expansion of water to steam at 1 atm. Using excess water with respect to the size of vessel 110 leaves behind a large thermal mass of hot water that will take longer to cool T2 or T3 ' . Hence, in most applications with vessels ranging in capacity from 1 to 6 liters, only 30 to 60 ml is sufficient.

[0085] As induction vessel 1 10 has a magnetic or other receptor layer 1 15' in the exterior bottom 115 of the vessel 111 that is heated directly by the generation of eddy currents therein only when the induction coils are energized. When the vessel 110 and contents are not being heated by a thermal mass of non radiant heater, or any other part of the vessel (other than the contents) it is simpler to control the temperature in the vessel, as the vessel and contents are the only thermal masses that can lead to an overshoot of the control temperature. In the case of a radiant heat source such as the induction base, since very little water is needed to displace the air from the vessel, the circulating vapor will respond very rapidly to each instance of heating the receptor layer in the vessel bottom 115. While other radiant heat source can be used, such as IR heaters, the induction heating method is preferred as layer 115' is very thin and has very little thermal mass so that once internally heated, rapidly transfer energy to the interior of the vessel 110.

[0086] This vapor flow, in a well or deep evacuated vessel 110, exposes the

supported foodstuff 1 to a very uniform and temporally stable temperature during t3. Hence, the thermal probe 322 intruding into the interior of the vessel 110 via a portal 205 in the lid 200 is providing an accurate

measurement of the foodstuffs environment. Moreover, any change in temperature is also rapidly detected. This has been verified with a large 32 cm diameter wok shown in FIG. 6A, with the resulting temperature in two location under various heating and vacuum levels shown in FIG.7-9.

[0087] Moreover, various methods of controlling the output of an induction heater with digital electronic are well known. US Pat. No. 5,700,996 discloses various means of supplying a predetermined current to the resonant coils of an induction cooker for induction heating a mounted vessel, and is incorporated herein by reference.

[0088] US Pat. No. 6,630,650 discloses a digital control system for control of the output power of an induction cooker, and is incorporated herein by reference.

[0089] US Pat. No. 8,373,102 discloses an induction cooker with automatic control of the heat output, including in response to selection of a cooking mode, and is incorporated herein by reference.

[0090] With an accurate and rapid measurement of temperature feedback to the

power controller (by RF or wired connection) the heat source 400 below the vessel 110 is energized precisely as necessary to maintain a steady temperature, or any targeted temperature profile. [0091 ] The temperature and pressure during the steps in the process of FIG.2 are illustrated schematically in FIG. 4. T2 is the temperature sufficient to form a deep vacuum (that is greater than 95% drop from atmospheric pressure that is 0.05 Bar or 0.7 psi) before heating to a higher cooking temperature, T3. If the desired cooking temperature, T3' is lower than T2, cooling is allowed to continue until T3' is reached with a re-energizing of the heater 160 at T2. T2 is generally about 180 to 190° F.

[0092] In FIG. 2, the vessel 110 is heated with full power during tl to reach Tl, which is at or below 212F. The vessel 110 is maintained at this temperature for time t2. It should be noted that as tl is measured by the control system, as it is predictive of t2, which is the time of additional heating time need to expel air from the vessel 110. When the air is expelled, and the power to the heater is reduced or eliminated so that during the start of t3, the pressure drops. Heating can start again when measured temperature teaches the target cooking temperature T3 ' . Alternatively, for a higher cooking temperature, the temperature should at least reach T2, to assure an adequate vacuum before being raised to T3', final cooking temperature. In a preferred embodiment, the consumer can visually confirm a sufficient vacuum reached, as it would compress and urge the gaskets 250 down the curvilinear rim 113, it is no longer apparent. T3, is the cooking time, optionally includes the times required after t2 to drop the temperature from Tl to T3.

[0093] Referring back to FIG. 2, after cooking is complete an alarm or warning light on the base of the heater 400 can be activated (180) indicated to the cook that they can either vent the vessel and remove the lid in step 109" to serve food, or optionally reduce the temperature in step 109 for holding the food until serving, and optionally in step 109" re -warm the food to a serving temperature in step 109'.

[0094] It has been discovered that the low pressure steam atmosphere will heat food relatively rapidly, even at low temperature, in contrast to conventional Sous Vide cooking, in which food is sealed in plastic bags.

[0095] Although the vacuum need not exclusively be formed by boiling the water at atmospheric pressure, the optimum conditions to evacuate the vessel 110 has the benefit that food stuff surface is sterilized by the initial steam that is at Tmax, or about 209-212 °F, in addition to the lower cost and greater reliability that the addition of an external vacuum pump. In an additional embodiment a mechanical vacuum pump can be housed in the thermal sensor 300, and can run for a predetermined time before the thermal sensor sends an RF signal to the heater 400 to start heating water.

[0096] The overcooking of delicate foods during tl and t2 can also be avoided by placing them on a rack or plate supported above the bottom of the vessel 110, or alternatively by providing thermal barriers, such as wrapping or sealing in plastic films, bags, wax paper, aluminum foil, or organic and/or edible materials such as parchment paper, grape, fig or banana leaves, corn husks and the like. [0097] Alternatively, vacuum can be established by mechanical means, such as a vacuum pump 500, as described in other embodiments. In FIG. 16B, the pump is integrated into the thermal sensor housing 330, with air exhausted through a tube 501 in the grommet, in which the thermal probe 322 is concentric with the tube 501. The double headed arrow shows the air exhaust path form the tube 501 to the pump 500, and from the pump 500 to an exhaust portal 502 on the side of the housing 300.

[0098] When the vessel 110 is small (relative to the foodstuff) and the amount of added water or other aqueous fluid (added to create the steam that excludes the air) is not excessive, the vessel 110 interior will promptly cool below 212F to the desired cooking temperature, avoiding overcooking a delicate foodstuff. In such conditions the thermal mass of the foodstuff precludes heating more than just the exterior to 212°F. In addition, supporting the food on a rack further from the exterior heat source also prevents overheating the foodstuff. [0099] Excess fluid, that is more than necessary to create the boiling film of water shown in FIG. 1, will slow down cooling to the cooking temperature which for cooking proteins can be as low as 128-140°F, as the excess water is simply an excess thermal mass that slows down the cooling process. This is partly illustrated in FIG. 4 and 19, which plot the temperature change time necessary to reduce the pressure in the vessel 110.

[001 00] Alternatively, more robust or larger foods can be seared in the vessel at high temperature on one or more sides prior to deploying a lower temperature cooking mode under controlled temperature to cook the foodstuff through the thickness. The juices and flavoring compounds formed during searing can then be used to create a sauce or gravy, in combination with additions of one or more of wine, beer, fruit juices and meat, poultry, or fish and vegetable stocks, with the addition of other seasoning. It has been discovered that the subsequent cooking in the sealed vessel at the lower temperatures preserves and enhances the flavors creating in searing, and infuses them into the food stuff. In contrast, unsealed atmospheric pressure steaming can strip foods of natural flavors and vitamins.

[001 01 ] Hence, the deployment of the inventive cooking apparatus and methods can produce food of quality comparable to and frequently exceeding that Sous Vide slow cooking, in less time without bagging and vacuum sealing food.

[001 02] Referring back to FIG. 1, even after displacing air in the vessel 110 ( by pump or steam expulsion), a thin layer of water or other aqueous fluid 1 on the bottom of the pan (chamber) is heated by an external heating plate or other source 460, and boils at lower temperature under reduced pressure. The arrows represent the inherent and water vapor circulation that is caused when the water rises in temperatures shifting the equilibrium in the vessel to the production of more water vapor. As will be discussed in further detail below, although the heated steam rises to the top of the vessel 110, the temperature in the vessel 110 is readily controlled in the case of an induction cooker base as the heating element 460. In such conditions the temperature in the center of the vessel 110 will be relatively consistent, even when the temperature is measures for control purposes inside the vessel 110 but just below the lid 220 at thermal probe 322.

[001 03] Not wishing to be bound by theory, it is currently believed that the penetrating potential of the circulating steam penetrates some foods rapidly, more efficiently than transferring heat than a water bath can to vacuum sealed food.

This is somewhat confirmed by the ability of some foodstuffs to absorb aromas from seasoning added to the foodstuff, as well as to the aqueous fluid.

Such aromas can be created by aromatic seasoning arranged on the foodstuff, such as ginger, garlic, scallions, onion, lemon grass, or placed in the aqueous fluid. As the vessel 110 is sealed in the process of cooking, volatile flavoring compounds are not lost to the external atmosphere, but preserved and concentrated as a flavor element.

[001 04] However, this beneficial circulation of low pressure steam arises when the air is expelled and remains excluded. Such conditions are achieved by an optimum gasket design that allows the steam that displaces air to escape during tl and t2, but also rapidly forms a tight seal at the transition on the initial condensation of steam at the start of t3. If the gasket does not seal the vessel 110 immediately on cooling, then cooler air can be sucked in, and the high vacuum state that uniform and rapid transfer of heat from the receptor portion of the vessel bottom to the water vapor will not be reached, resulting in a larger temperature fluctuation shown in FIG. 7-9. In such conditions the thermal measurement will not be adequate, the foods is easily overheated, as well as exposed to oxygen which can destroy some flavor during long cooking cycle.

[001 05] Hence, it should now be appreciated that the full benefits of the innovative cooking equipment and method are only reached when the vessel 110 construction, heating and measurement, method and control scheme are optimized to work in the cooperative manner disclosed herein. [001 06] FIG. 4 illustrates a preferred control scheme to maintain a constant

temperature, or series of constant temperatures, after T3 is reached. However, the control method of step 107 can deploy any known process control method. The currently preferred mode deploys a sequence of short energy pulses from the induction bases 400 to raise the temperature when a lower control limit is reach. The lower control limit (LCL) is preferably set at about 0.25°C lower than T3, whereas the upper control limit (UCL) temp is set at or slightly above the desired cooking temperature, T3 by about 0.375 °C.

[001 07] Hence, FIG. 3 is a schematic plots of the application of short power pulses with time (Pn, P_n+i and P_n+2) showing the typically measured temperature response in the preferred control scheme. When the LCL is reached on cooling from the unpowered mode the induction heater is energized for a brief predetermined time period, a pulse, preferably for about 5 sec, in the case of a 600W output. The temperature will then rise in response to heating, reaching a peak Tn, associated with the previous power pulse. However, because of heating delays the measured temperature may actually dip slightly below the

LCL before rising after the heating pulse. After the recording by the controller 430 of Tn after each pulse, the controller 430 is operative to compare Tn with the UCL, LCL and T3 values to apply an appropriate amount of energy in the subsequent pulse (P _n+1) as follows: lengthen the pulse to increase the energy when Tn is below T3; shorten the pulse to reduce the energy when Tn is above the UCL, and apply the same energy in the pulse when Tn is between or equal to either the T3 and the UCL. Hence, when the LCL is reached for a second time a subsequent pulse (Pn+1) is applied, however the pulse time is modulated based on the difference between Tn and T3. The pulse width or time is lengthened when the prior pulse resulted in a local temperature maximum, Tn, is below T3, and shortened when the prior pulse resulted in a Tn above the UCL. Subsequent power pulses applied on cooling to the LCL are similarly modulated so the temperature remains between the UCL and T3. It is preferable to provide such a method of pulse width control at the lowest output power setting. Alternatively, the output power can be increased rather than lengthening the pulse width.

[001 08] A higher than minimum power can also be used with reducing power rather than shortening the pulse width. Alternatively, the temperature rise rate and maximum temperature after each pulse can be used to calculate a subsequent pulse width or power to more precisely limit the rise between subsequent temperature peaks.

[001 09] Further, the subsequent pulses of reduced power can be applied before the temperature reaches the LCL to provide a reduced fluctuation between eh UCL and LCL. [001 1 0] US Pat. No. 5,004,881 discloses induction cooker base construction and methods of power level control in an induction cooker using a combination of time duty control of the power level and a pulse width modulation control method, which are applicable to this disclosure, and is incorporated herein by reference.

[001 1 1 ] FIG. 7-9 graph the measured temperatures at probe 322 and a test thermal probe on rack 5 in FIG. 6 in a range of conditions to illustrate importance of air expulsion in step 105 to achieving the tight thermal control necessary for achieving the process control that provides equivalent cooking results to water bath based used in Sous Vide equipment. It should appreciated that during actual measurement induced current into an thermal probe 322, such as a thermistor or thermocouple, can result in short negative spikes in thermal sensor output. As such spikes last the 6±lsec. of the heating pulses, and pulse generally need to be applied no sooner than 30 to 90 second intervals, such spikes can be ignored in the control scheme or removed with a band pass filter. Pulses of 600 watts of 5 sec. duration are generally applied every 40 to 200 sec when UCL and LCL are between 0.5 °C. Alternatively, the UCL can be set slightly above the target cooking temperature, since larger food stuffs that cook slowly will gradually rise in internal temperature, as the heat transfer process is driven by the average cooking temperature between the

UCL and LCL.

[001 1 2] It should be appreciated from FIG. 7 A to 7C that in the condition in which most of the air is expelled (0.08 Bar) while the temperature sensing portion of the probe 322 is positioned just inside the lid 200 it measures a slightly higher temperature after each power pulse, but the rack temperature is much more stable, that is varies less than the circa 0.5° C (circa 1°F), which is the temperature difference between the UCL and the LCL. Further, in the well evacuated vessel 110, the probe and rack temperature correlate extremely well on allowing cooling from a first control temperature of 158° F to a second control temperature of 140 °F, when the heater is not energized. [001 1 3] In contrast, as shown in FIG. 7B, at a residual of air equivalent to 0.3 bar a thermal lag is apparent at the rack position and the rack temperature is less stable, that is drifting at circa 140 °F. This lag increase further absent air displacement by water vapor (1 Bar in FIG. 7C), as the thermal lag is considerable between the entire cooling stage from 158 °F to 140 °F, and the both the probe and rack temperatures drift and vary considerably.

[001 1 4] The poor thermal control in the absence of air removal is most apparent at the lower temperature of circa 120°, as shown in FIG. 8 A and 8B which now compare the and probe 322 temperature to the temperature measured on the rack 5 located at the food supported position below the vessel rim 113 when the LCL is 120 °F. In the lowest residual air condition (0.08 Bar) the probe position varies predictably by about 0.8 °F ,with the rack position stable to less than 1°C, with the probe temperature never exceeding the UCL. However, absent the air removal, as in FIG. 8B, both the probe temperature is not controllable between the UCL and LCL, and the rack temperature thus varies by about 2 °F (more than 1°C). Further, the measured temperature in the greater than 0.08 bar air evacuated vessel undergo considerable drift over time, in FIG. 7B and 7C even at higher temperature

[001 1 5] FIG. 9A -C illustrate the great stability of control in the 0.08 bar condition over a series of temperature plateaus, including the cooling transition between them. At the highest plateaus of 176 °F and 158° F the rack and probe temperature rise within the UCL after each power pulse. However, at the lower highest plateaus of 140 °F and 122° F, the rack temperature is very stable, and does not rise with the probe temperature or drift. [001 1 6] It should be appreciated that when it desired to limit the initial temperature exposure during air expulsion, this is best achieved with a smaller vessel 110 or setting a lower temperature for Tmax, or time t2, which will somewhat reduce the control capability within the UCL and LCL.

[001 1 7] The cooking method and apparatus avoid raising the foodstuff internal

temperature to a level at which foods detrimentally change in texture, flavor or nutritional content. In the case of proteins, cooking temperature is the primary determinant of the state of doneness, with the optimum softness and moisture content to provide a satisfying and mouth feel. Overcooking protein makes meat tough, though some animal proteins with a high content of collagen, eventually soften after extended cooking times, when the collagen dissolves. With the inventive apparatus, it is possible to dissolve collagen slowly a lower temperatures without overcooking the protein so that tougher cuts of meat become extremely tender without excess fat, and a flavorful sauce is created in the pan. [001 1 8] The cooking method is believed to preserves vitamins and flavors. Further, the cooking method does not require sealing the foodstuff in a plastic bag. An additional benefit is that only a small quantity of water needs to be used, in contrast to Sous Vide cooking in which a water bath sufficient to immerse the entire plastic bag containing the food is required. Further, in contrast to many types of Sous Vide cooking equipment, the kitchen is not continuously filled with steam. However, nothing precludes sealing food stuffs in a plastic bag or other container and using the low pressure steam as the heat transfer fluid

[001 1 9] It should also be appreciated that a less preferred but alternative temperature control and measurement means also compatible with an induction burner is an external thermal probe 120 is mounted in the center of the heating plate having a resilient means, such as the spring, then urges the thermal probe to contact the bottom of the cooking vessel 110. Another alternative temperature control and measurement means is when the thermal probe or sensing portion 322 thereof can extends anywhere into the interior of the vessel 110, such as optionally the water 1 in the bottom.

[001 20] FIG. 10-11 illustrate the interaction of a preferred gasket 150 with a preferred cooking vessel 110 and portions of the lid 200. The combination provides rapid and stable vacuum sealing during the heating cycle of FIG. 2-3, but allows the vessel to be used with other lids, including the lid shown in FIG. 17, in which the thermal sensor is external to the vessel. The lid rim 214 is configured to form a sealed mated engagement with the rim 210 of the cookware vessel 200. To this end, the lid rim 214 includes a cylindrical portion 214a that is generally parallel with the vessel sidewall 112 when the lid 200 is assembled with the vessel 110. The lid rim 214 also includes an outwardly-extending flange portion 214b disposed at the free end of the cylindrical portion 214a that is generally parallel with the vessel base 115 when the lid 200 is assembled with the vessel 110. Together, the cylindrical portion 214a and the flange portion 214b form an inverted "L" shape for receiving a gasket member 250. The lid rim 214 includes a pliable gasket 250 that is disposed within the interior angle defined between the cylindrical portion 214a and the flange portion 214b, and extends about the circumference of the lid rim 214. When viewed in cross section, the gasket 250 generally has an upright "F" shape that permits the gasket 250 to matingly engage, and form a seal, with the inner rim 113 of the vessel 110. The gasket 250 includes an upper horizontal arm 251 , a lower horizontal arm 252, a vertical portion 253 that extends between the upper horizontal arm and the lower horizontal arm, and a skirt 254 that is an extension of the vertical portion 253 and depends from the lower horizontal arm 252. The upper and lower horizontal arms 251 , 252 taper in thickness toward their terminal (e.g., free) ends 25 la, 252a. This provides greater flexibility at the free ends 251a, 252a; however, the root, or portion closest to the vertical portion 153, of each arm 251, 252 is made thicker to provide support when the free end deforms to conform to the curved shape of the interior surface 113a of the vessel rim 113 under an evacuated condition of the vessel 110. The upper horizontal arm 251 is longer than the lower horizontal arm 252 to accommodate curvature of the vessel rim 11. The gasket 250 is oriented within the interior angle such that the upper horizontal arm 251 adjoins, and is sealingly mated to, the lid rim flange portion 214b and the vertical portion 253 adjoins, and is sealingly mated to, the lid rim cylindrical portion 214a. In particular, the vertical portion 253 is shaped to conform to the shape of the outer surface of the cylindrical portion 2140a, and thus in some embodiments may be curvilinear. This feature ensures contact by providing a larger sealing area, and secures the gasket 250 to the lid 200 when the vessel 200 is vented by lifting the valve 240 to the open position.

[001 22] The gasket 250 has centering ribs 255 formed on the skirt 254 that are

equidistantly spaced apart about the circumference of the lid rim 214 (FIG. 10A). In the illustrated embodiment, the gasket 250 includes four ribs 255 that are separated by 90 degrees about the gasket center. The ribs 255 protrude outwardly from the skirt 254 toward the vessel sidewall 112. In portions of the gasket 250 between the ribs 255, the skirt 254 has a thickness thl (Fig. IOC), and in portions of the gasket 150 corresponding to the ribs 155, the skirt 254 has a thickness th2, where th2 is greater than thl (Fig. IOC). The ribs 255 aid in centering and seating of the lid 100 within the vessel rim 210 to assure a repeatable vacuum seal, and also eliminate vibration during sealing.

[001 23] Referring to Fig. 11, when the lid 200 is assembled with the vessel 110 in a non-vacuum state (e.g., the vessel interior space is at atmospheric pressure) such as during cooking or when the valve 240 is in the open position, the lid 200, the free end 252a of the lower horizontal arm 252 contacts the curvilinear portion 213a of the inner surface of the vessel rim 113 to support the lid 100 relative to the vessel. The arm free end 252a sealingly engages the curvilinear portion 213 over a relatively small area PI, corresponding to the size of the tapered free end 252a along the circumference of the vessel rim 210. The initial contact area is narrow enough to allow vapor to escape without disturbing the lid alignment. When viewed in cross section, the area PI generally corresponds to a single point of contact. In this position, the upper horizontal arm 251 and the skirt 254 of the gasket 250 are spaced apart from the vessel rim 210, and a vertical gap G exists between the lid flange portion 110b and the vessel rim 210. [001 24] Referring to FIG. 1 IB, when the lid 200 is assembled with the vessel 110, the valve 240 is in the closed position ( or thermal probe 322 filling gasket 170 disposed in penetration 205, and the vessel 110 is in a slightly vacuum state such as occurs when steam trapped within the vessel condenses, the weight of the lid 200 and the atmospheric pressure enlarge the area contacted by the lower horizontal arm 252. The contact area PI is enlarged to area PI ' by the distortion of the lower horizontal arm 252 as it more fully engages, and conforms to the shape of, the vessel rim surface 211, e.g., Ρ > PI . In particular, the side 252b of the lower horizontal arm 252 contacts the curvilinear portion 211 of the inner surface of the vessel rim 210 to sealingly engage the curvilinear portion 211. In addition, the upper horizontal arm 251 sealingly engages the vessel rim surface 113a whereby an upper contact area P2 is formed where the upper arm 251 contacts the rim surface 113a, and the skirt 254 engages the inner wall of the vessel 110 below the rim 113 whereby a lower contact area P3 is formed where the skirt 252 contacts the rim surface 113a and/or vessel sidewall 112. Further, as the lid descends, the vertical gap G provided by the gasket 150 is reduced or eliminated.

[001 25] By providing multiple seal locations (PI ', P2, P3), the vacuum seal reliability is improved and vibration during or after sealing, which can create an annoying audible noise (ringing), is eliminated. In addition, the described configuration precludes the gasket 250 sticking to the rim 113 when the vessel 200 is vented by lifting valve 240 or removing thermal sensor 300.

[001 26] FIG. 12-14 illustrate another aspect of the preferred lid 200 that includes the handle 215, as well as a vent valve 240 that can replace the thermal probe when the vessel is used normally, or in an oven as shown in FIG. 17. In alternative embodiments of the invention an alternative vessel venting means 111 is preferably a sealable portal in the lid 200 of the vessel 110, as shown in FIG. 6A. [001 27] Referring to Figs. 12A-12D, although the handle assembly 215 is illustrated with the valve 240 disposed in the opening 205, the handle assembly 215 is not limited to this configuration. For example, in an alternative handle assembly 215, the valve 240 is replaced with the probe 322 and a grommet 170 that lines the opening 205 and supports the probe 322. The grommet 170 includes a cylindrical sleeve 171 that includes an outwardly-extending stop flange 173 formed at one end thereof. When the grommet 170 is disposed in the opening, the stop flange 173 rests on the ring member base plate 132 and retains the grommet 170 in a desired position relative to the opening. The inner surface of the sleeve 171 defines a bore 172. The outer surface of the sleeve 171 is shaped and dimensioned to correspond to the shape and dimensions of the opening 205. The temperature sensing probe 322 is received within the grommet bore 172 in a sealed manner, and the outer surface of the grommet sleeve 171 is fitted within the opening 205 and forms a seal therewith. Thus, the handle assembly 215 permits a temperature sensing probe 322 to be inserted into the vessel 110 in a sealed manner. The wireless transmitter 300 may be energized with an external switch 382.

Removing the temperature sensing probe 322 from the bore 172 permits venting of the cookware vessel 110. In other embodiments, the thermal sensor can be replaced with a plug that fills the bore 172, in the grommet 170 to provide an alternative obstruction which cooperate to seal and close the opening 205. Such a plug 111 in FIG. 6A is also a vacuum sealing means.

[001 28] In the embodiment illustrated in FIG's. 13-14, the valve 240 is generally

recessed in the handle 220 when in the closed position. However, in some embodiments, the valve 240 may have a portion that protrudes beyond the outer surface of the handle 120 when in the closed position.

[001 29] In the illustrated embodiments, the central opening 205 is circular in shape, but it is contemplated that the opening 205 may alternatively be formed having other shapes, including oval and rectangular. [001 30] Although the gasket 150 is described herein as having a generally upright "F" shape, the gasket 150 is not limited to this configuration. For example, in some embodiments, the gasket 250 may have a "U" shape that opens toward the vessel rim. [001 31 ] Although the lid 100 is described herein as being formed of metal, it is not limited to this material. For example, in some embodiments, the lid 100 is formed of glass or plastic. In other embodiments, the lid is formed of metal and transparent glass. In still other embodiments, the metal lid is coated with enamel or other material. [001 32] Although the lid 200 is described as having a single, central opening 205, in some embodiments, such as FIG. 6, it is not limited to this configuration. For example, in some embodiments, the lid 100 includes multiple openings clustered at the lid center. In the illustrated embodiments, the handle 120 is formed of a material that is stable at high temperatures. In some

embodiments, this material is rubber or silicone rubber, or a thermoset plastic resin, such as phenolic resin and the like.

[001 33] As shown in FIG. 12D, the sidewall of the thermal probe 322 are used to seal the vessel 110 via a gasket 116 the removal of the thermal sensor 220 provides a venting means 111. [001 34] The lid 200 is a dome shaped member having an outer surface 202 and an opposing inner surface 204, which co-terminate at an annular lid rim 214. The lid 200 is formed of metal and includes a central circular opening 205 that extends between the outer surface 202 and the inner surface 204.

[001 35] Referring to Figs. 13-14, the handle assembly 215 is used to lift the lid 200 and control vacuum pressure within the vessel 200. The handle assembly 215 includes the handle 220, a ring member 230 that secures the handle 220 to the lid 200, and the valve 240.

[001 36] The annular handle 220 is situated in the geometric center of the lid 200 and surrounds the opening 205. The handle 220 is formed of a material that is stable at high temperatures, and has a first end 222 that abuts, and conforms to the shape of, the lid outer surface 202. The handle 220 has a second end 224 opposed to the first end 222. The handle second end 224 defines an outwardly protruding shoulder 223 that serves as a gripping surface, and is tapered so as to be slightly recessed relative to the shoulder 223 in a central portion thereof. The handle 220 has an inner surface 225 that extends between the first and second ends 222, 224, is of uniform diameter and of larger diameter than the opening 205. Equidistantly spaced slots 228 are formed in the handle inner surface 225 that are sized and shaped to correspond to the size and shape of struts 236 provided on the ring member 230, as discussed below. A circumferential groove 221 is formed in the handle second end 224 generally midway between the inner and outer surfaces 225, 226 of the handle 220. The annular portion of the handle second end 224 between the inner surface 225 and the groove 221 forms a land 227. The land 227 and the groove 221 are configured to receive and support a flange portion of the ring member 230, and the slot 228 is configured to receive and support the struts 236 of the ring member 230, as discussed below.

Referring to Figs. 13, 14D, 14F and 15A, the handle assembly 215 includes the ring member 230 that is configured to secure the handle 220 to the lid 200. The ring member 230 surrounds the opening 205 and is disposed between the handle 120 and the valve 240. The ring member 230 has a cylindrical support portion 235, an annular base plate 232 that is connected to a lid-facing end of the support portion 235, and a flange portion 231 connected to an opposed end of the support portion 235. In some embodiments, the support portion 235 is formed of struts 236 that extend between the flange portion 231 and the base portion 232. The base plate 232 is disposed concentrically about the lid opening 205, and is secured to the lid outer surface 102, for example by welding. To this end, the base plate 232 includes mutually spaced spot weld centering holes 239. The flange portion 231 protrudes outward from the support portion 235 in a direction away from the opening 205 and toward the lid rim 110. The flange portion 231 is shaped to conform to the land 127 and the groove 121 of the handle 120. In use, the base portion 232 is fixed to the outer surface 102 of the lid 100 so as to surround the opening 205, and the struts 236 are received in the slots 128. Since the slots 128 engage the struts 236, the handle 120 is prevented from rotating relative to the lid 100. In addition, the flange portion 231 is received within and engages the land 127 and groove 121 of the handle 120, whereby the handle 120 is retained against the outer surface 102 of the lid 100.

[001 38] Referring to Figs. 13 and 14A-C, the handle assembly 215 includes the

vacuum sealable valve 240 that is disposed concentrically within the ring member 230 and the annular handle 120. The valve 240 is elastic, and has a disc-shaped main portion 244 disposed within the ring member 230 so as to be moveable relative to the ring member 230. The valve 240 also includes a generally-cylindrical stem portion 245, and an elongated release portion 246. The stem portion extends from a lid-facing side of the main portion 244 and is shaped and dimensioned to seal the lid opening 205 in some valve positions

240 relative to the handle 120. The release portion 246 extends from the lid- facing side of the stem portion 245. The release portion 246 terminates in a pair of legs 248 that protrude from opposed sides of the release portion 246 in a direction general parallel to the lid 100 (FIG. 14B). The legs 248 are dimensioned to be larger than the opening 205, whereby the legs 248 retain the valve 240 in the opening 205. In addition, in the direction transverse to the legs 248, the release portion 246 has a cross sectional dimension that is small relative to the stem portion 245 and the opening 205 (FIG. 13 and 14A). In other positions of the valve 240, the release portion 246 is configured to provide venting to release a vacuum within the vessel 200 by admitting external air into the vessel 200, as discussed further below.

[001 39] Referring to FIG. 15B, the valve 240 is operative to translate relative to the handle 220 and the opening 205 between a first, closed position (FIG. 15B ) and a second, open position (FIG. 15C). In the closed position, the valve 240 is retracted into the space defined by the handle inner surface 225. As a result, the stem portion 245 is disposed in, and sealingly obstructs, the opening 205. That is, when the valve 240 is in the closed position, the stem portion 245 prevents air flow through the opening 205. In the open position, the valve main portion 244 is partially advanced outward from the handle 220 so that the stem portion 245 is withdrawn from the opening 205. In this position, the stem portion 245 is located on an outer surface-side of the lid 200 so as to be adjacent to and aligned with the opening 205. In addition, the release portion 246 extends through the opening 205. Since the release portion 246 has a dimension that is smaller than that of the opening 205, air can flow through the gap between the release portion 246 and the opening 205, whereby the vessel 200 is vented.

[001 40] The valve 240 is manually opened or closed at the user's discretion. To this end, the outer face 244a of the main portion 244 includes indents 241 configured to permit gripping of the valve 240.

[001 41 ] The valve main portion 244 may include features that permit the user to

visually determine the position of the valve 240 relative to the lid 100. In the illustrated embodiment, the peripheral edge 244b of the main portion 244 includes a circumferentially-extending groove 243, and an indicator ring 242 is disposed in the groove 243. The indicator ring is formed having a color that contrasts with the color of the handle 120 and possibly also the other portions of the valve 240. When the valve 240 is in the open position (FIG. 15C), the indicator ring 242 is visible to the user, indicating the valve is in the open position. When the valve 240 is in the closed position (FIG. 15B), the valve main portion 244 is retracted within the handle 220 and the indicator ring 242 is not visible to the user, indicating that the valve 240 is in the closed position. [001 42] In FIG. 16, the vessel is capable of operation above and below atmospheric pressure, in which the air and steam are initially expelled through a valve before operating in the vacuum mode, in which the valve is either one way or closes after time t2. The valve can be closed manually after time t2, using a signal such as a light, sound, from the base 400 for the user to perceive.

Alternatively, the valve can be closed with a solenoid type valve via an electronic signal from the controller 430. The lid 200 has a bayonet or jaw type clamps to retain pressure after the valve is sealed. This configuration allows cooking at controlled temperatures above about 190°F, once the valve is closed, up the safe operating pressure set by a safety release valve, which is generally at between about 5 to 15 psi. [001 43] FIG. 17 is a cross-sectional elevation view of another embodiment of the cooking apparatus 1000 suitable for low-pressure steam cooking in which the vessel 110 containing the raw food, or food to be warmed is within another vacuum vessel 700. Preferably vessel 700 is closed with hinges 750 which attach the lid 17200 that contains the temperature sensor 17122 for measuring vapor temperature. A gasket 17250 seals to lid 17200 to the lower portion 730 that extends above vessel 110 to the hinged rim. The vessel 700 may also contain a planar heating member 17460 that makes direct contact with the bottom 115 of the vessel 110. More preferably, a second thermal sensor 17120 is spring loaded and makes contact with the exterior bottom 115 of the vessel 110, preferably being in the center of but not directly heated by planar heating elements 17460. The planar heating elements 17460 can be heated by electric resistance heating coils, in the which the current is controlled by the controller 17430, in response to the predetermined time and temperatures regimes described above, as measured by one or more of thermal sensor 17122 or 17120.

[001 44] More preferably the control system 17430 is integrated into base 17100 of a device 1000 that includes vessel 700, along with the connection to the planar heating members 17460. A control panel and appropriate status indicators would be on the exterior of the vessel 700 and/or base 17100. [001 45] The vapor temperature sensor 17122 can then be in signal communication with the controller 17430 via a wired connection, such as one 730 extending from the lid 710 to the sidewall outside vessel 700. Alternatively, the vapor thermal sensor 17122' can be in niche in or extending from the sidewall of the interior of vessel 700, being above or spaced away from the food containing vessel 110. The vent means 17111 in lid 17200 preferably is a one way releasable valve that prevents pressure build-up in vessel 700, but will self close to form a vacuum, and as is easily opened by pulling upward, such as 220

[001 46] Hence, the apparatus 1000 of FIG. 17 has the advantage that external power of the controller and heaters avoids the need for a battery powered or other RF transmitter in the lid, simplifying consumer use and reducing costs. As with other embodiments, the device 1000 is also capable of other cooking mode, such as rice cooking or slow cooking liquid ingredients mixture, either with or without the exclusion of air depending on the state of vent mean/valve 111.

[001 47] In another aspect of the invention, illustrated in FIG. 18, the vacuum

compatible vessel 1 10 is filled with food stuffs, evacuated to a partial vacuum, and then introduced into temperature controlled oven 18400 in which the temperature is less than 100 °C. The vacuum in the vessel 110 can be achieved by a heating process to create steam and displace air, after which a slight cooling on condensation creates the vacuum. This mode avoids the need for an exterior electronic thermal sensor 300 in the lid 200. The replacement of air with steam can be accomplished on a regular store top or range, as well as an induction base, provided the heating cycle is timed and/or measured to expel most of the air, as described with respect to FIG. 2 and 4.

[001 48] Alternatively, the vessel 110 can be evacuated with a hand held or removable vacuum pump line via a closable or 1 way valve. The surrounding oven 18400 then replaces the heat source, such as the induction burner, and so long as the oven 18400 deploys an accurate internal temperature measurement device 18322 and an advanced thermal control system, such as a PID type feedback system to maintain the temperature at constant level, a thermal measuring device need not enter the vessel. Convection ovens are particularly well suited to this purpose, as the convective mixing of air provides a uniform temperature. So long as the temperature measurement device 18322 measures the oven air temperature, the food stuff inside the vessel will not exceed this temperature, and will slowly reach this temperature throughout the food contained therein.

[001 49] The convection oven 18400 in FIG. 18 would preferably deploy an internal ventilation system 18001 in which a fan 18430 withdraws air from a portion of the oven 18400 and then return the air to a different part of the oven by passing it over a heater element 18460. At least one thermal probe 18322 is in signal communication with a control system to continuously measure at least one of the internal oven the temperature, or the temperature inside the vessel (18322') being insert in a gasket or other sealable portion of the lid 200 or lid vent 240. The opposing portion of probe 18322' would be connect to the oven's internal controller via a feed-through 18301 in the interior oven wall after the vessel 110 were evacuated, either with a hand-held pump or pump line, or by heating and cooling on range top/induction base. The control system can energize the heater and or fans as required to maintain a predetermined temperature or temperature profile, as generally described with respect to other embodiment. This method has advantages in restaurants and other commercial kitchens in that a single oven can hold multiple vessels for cooking and storage until the food needs to be served.

[001 50] It should now be appreciated that the inventive cooking apparatus and method is desirably deployed on induction ranges that are build into a counter top, and include space for multiple vessels, or in kitchen that desire to use multiple deices 1000 at the same time. In order to avoid confusion of signal sent by a different transmitter 320 in each thermal sensor 300, the sensors can transmit at different frequencies. However, a simpler means is illustrated in FIG. 20 in which at the time of each transmission of signals (or signal packets for temperature measurements or control instructions) to the receiver 420 and hence power supply controller 430, in which each sensor sends a pairs of signals signal (S 1 and S2) with a different predetermined time interval between each signal in the pair. Accordingly, the controller 430 of each of the devices 1000 are programmed to recognize only pairs of signals at the associated predetermined spacing. In the worst case shown in FIG. 19, when the first and second thermal sensor 330 send a first signal in the pair at the same time, each controller 430 and 430' will only receive 3 signals or signal packets, and is also programmed with instructions to be operative to ignore the value of the first signal or signal packet, and use the second signal or signal packet that arrives at the proper delay time (from the overlapping pair) for control purposes.

FIG. 20 illustrates another important advantage of the inventive cooking apparatus and method over Sous Vide cooking in that large and irregular shaped food with open body cavities, such as whole fish and poultry can be cooked in an accelerated method using multiple temperature controlled stages. The same mode can be deployed in rice cooking or slow cooking liquid ingredients and mixture, in which it is desirable to heat or seer food art a high temperature briefly, and then complete cooking at a lower temperature. The FIG. 20 is a schematic diagram of the temporal variation of temperature and in the vessel of FIG. 1 resulting from another mode of operation according to the flow chart in FIG. 2 First, the heater 460 is energized at full power and the time, tl, to reach Tl( generally 210°F) is logged by controller 430. The time, t2, to hold at maximum power (during which T_max is reached) and expel air is calculated as described above and the heater is then de-energized to allow cooling to a first pre-determined cooking temperature T2. T2 is maintained using any of the process control schemes described above for time t2'. In the case of large poultry or whole fish of 3-4 lbs, or frozen seafood, T2 is about 150 to 180 °F and the holding time t3 about 10-30 minutes. Then after t2' is reached the heater is again de-energized to allow cooling to T3, during which T3 is maintained using any of the process control schemes described above for time t3. T3 is generally the final cooking temperature that corresponds to the level of doneness of protein, such as circa 128 -135 °F for fish or seafood, and 130 -165 °F for meat or poultry, in which t3 is dependent on the food thickness or weight. In this example, T3 is the optimal temperature to avoid over cooking and dehydrating proteins, keeping the cooked foodstuff satisfyingly moist and flavorful. More stages, between T and T3, can be deployed to accelerate cooking, while a progress lowering of temperature to avoid overheating the food exterior in the earlier stages.

[001 52] After t3, the heater controller 430 can be operative to hold the food at a lower temperature, say T4, until serving is desired. In this case a manual instruction can be entered to heat the interior of the vessel 110 to T4', which is a final serving temperature, generally 150 to 170°F, to just warm the food exterior to this serving temperature, which takes only about for 1-4 minutes. The staged heating illustrated in FIG. 20 allows large poultry and whole fish, which are not amendable to Sous Vide cooking, to be finished in less than 1 to 1.5 hours. Frozen fish and shellfish are also amenable to this cooking method, and will not be overheated in the initial stage of creating steam to expel air. This staged cooking is possible because the air excluded state in which low pressure steam fills the vessel interior allows a rapid and accurate transition between temperature stages without overshooting the desired control limits.

[001 53] In addition after cooking is complete, the foods can be held at the final

cooking or a lower temperature until the cook is ready to server, in which case the controller 430 can be manually instructed to increase the temperature to a fourth or serving temperature for a limited time that will still avoid overheating the interior, but give a warmer flavor and mouth feel to food from a slightly warmer exterior of about 160 to 170 °F. The ability to rapidly heat food to a slight higher temperature (T4 in FIG. 3) than the cooking temperature (T3 or T3') just before serving to enhance the mouth feel of warmer food and increase flavor release without over cooking. This is not practical using a water bath as a cooking medium because of the relatively long time it takes to increase the bath temperature, where the water vapor temperature will increase almost immediately when the vessel 110 is heated internally by the induction coils. Alternative Means for Vacuum Formation

[001 54] In additional embodiments, described below with respect to FIG. 21 to FIG.

24, there are alternative means to form the vacuum than initially heating the vessel to generate a sufficient volume of water vapor to displace the air therein. These embodiments are fully compatible with and can incorporate any previously described features relating to the heating means, thermal control and thermal measurements means, as well as the lid and lid sealing means.

[001 55] In one such embodiment, now illustrated with respect to FIG. 21, the vessel is optionally manually or automatically evacuated via a port 2130 in the lid 200. The evacuation can be with a mechanic pump 2210 in fluid communication with the port 230 in the lid 200. The mechanic pump 2110 can be integrated into the unit base 400 and housing 401, in signal communication with the control system 430, and powered from the mains power supply, as is also illustrated in FIG. 21.

[001 56] The fluid communication between the mechanical pump 2110 can be with a detachable hose or flexible conduit 2120 with an end portal that connects with any penetration in the lid 200, such as portal 2130 or optionally a penetration 2113 in the vessel sidewall 110. It is less desirable to penetrate the vessel sidewall, as the penetration 2130 of the specialized lid 200 a suitable gasket 250, enables the use of a wider range cooking vessels that are also suitable general purpose cooking. The fluid communication conduit 2120 for evacuating the vessel can be selectively closed manually, when a sufficient vacuum is reached, or optionally in response to a time period for evacuation being completed. The penetration 2113 or portal 2130 is preferably self sealing when the conduit 2120 to the pump 2110 is disconnected. This can be accomplished with a resilient mechanism that forces a sealing member to close an inner surface of the penetration when the inserted nozzle from the end of the conduit 2120 is removed. However, insertion of the conduit end would also urge the resilient mechanism open. The resilient member would be closed after the vessel is evacuated. Alternatively, the pump 2120 can be separate from the base housing, such as a hand held electric air pump, or a hand held manual pump. Manual pumps include hand held wine vacuum pumps.

[001 57] The mechanical pump 2110 can also incorporated in housing 2200 that is attached to the lid 200 and is powered by an integrated power supply, as illustrated in FIG. 22. The same housing can incorporate the thermal measurement means 300. As the pump 2110 is not powered by the base unit, it would deploy an internal power supply, such as a battery 2211

[001 58] The housing 2200 can rest on the lid 200, but be removable for cleaning, using the penetration in the lid illustrated with respect to the embodiments of FIG.

1,6, 12D, 13, 14F, 15A, 16A and 16B,

[001 59] It is particularly desirable to deploy a vacuum pump, rather than the steam expulsion method described with the embodiment of FIG. 1-20, when thin or delicate foods might be overheated in the initial stage of heating water to generate steam, or when it is desired to continue cooking with precision control after initially venting the vessel and discovering that the food is slightly underdone. This avoids the possible overheating in the preferred means of forming the at least partial vacuum via steam generation and subsequent cooling. [001 60] Prior art vacuum pumps suitable for incorporation in the housing 2200 or the heater hosing 401 included those that operate on the principles described in US Pat. No. 6,520,071 issued Feb. 18, 2003 (Lanza), as well as those disclosed in the published US Pat. Applications No.'s 2008/0308177A1, published Dec. 18, 2008 ( Thuat et al.) and 2008/0230144A, Sept. 25, 2008 (Anderson) all of which are incorporated herein by reference.

[001 61 ] Like the thermal sensor 300, the housing 2200 can be detachable and

preferably includes the previously described functions and features of the other embodiments of the thermal measurement means 300. As illustrated in FIG. 22 a programmable controller 310 within the housing 2200 can be in signal communication with the base unit programmable controller 430 by wireless connection as in other embodiment so that the controller 430 can energize the pump to form the vacuum before heating to the final cooking temperature.

[001 62] Alternatively, as shown in FIG. 23, the housing 2200 of the pump and

thermal sensor, both of which are in fluid and thermal communication with the vessel interior respectively, can be wired to the base unit for signal communication with the programmable controller 430 and power from the base unit, via cable 2300 that includes the signal wiring 2311 to the thermal sensor 300 and the power cable 2312 to the pump 2110.

[001 63] The thermal sensor housing 300 may also contains a pressure measurement means to that when any form of evacuation is complete, the controller 310 therein can send a signal to the base programmable controller 430 to initiate the heating process.

Charging External Power Sources

[001 64] To the extent that the thermal sensor 300 and/or pump 2110 are not powered by a direct connection to the heater base power supply, or another wired connection, they preferably powered by a replaceable or re-chargeable battery. It is desirable to be able to preserve battery life when the thermal sensor and/or pump is not used for cooking, and need not communicate with the base heating unit 400. A rechargeable battery for either a wireless sensor or pump can be charged from the base unit power supply with a separate extendable charging cord 2240 (FIG. 22), that connects to battery charging external socket 2212, either when removed from or in place on the lid 200. More preferably, the charging is by an induction circuit in place of a socket that makes an ohmic contact with the end of the charging cord 2240.

[001 65] Alternatively, as illustrated in FIG. 25A and 25B, the sensor 300 or pump and sensor combination 2200 can be stored in a slot or cradle 2501 in the heater unit base housing 401, proximal to the front control panel 2500. The cradle 2601 in the base unit housing 402 is preferably a mating depression that conforms to the lower surface contour of the sensor that fits in the vessel lid 200. [001 66] Hence, after removing the sensor 300 or pump and sensor combination 2200 the lid 200 it is disposed in cradle 2501. Cradle 2501 may provide various battery charging means, such an battery charging external socket 2212. More preferably the charging is by an induction circuit 2512 adjacent the cradles 2501. [001 67] An external light 2515 on the sensor, or control panel 2516 , can indicate the completeness of a charging process, as well as the establishment of a communication link with the base unit.

[001 68] The proximity sensor2514 can also activate the charging circuit that deploy s the induction circuit 2513 or ohmic contact to the battery at socket 2501. [001 69] It is also desirable to provide various means to preserve the charge and power in the battery of the sensor 300 or the pump 2200. Accordingly, the sensor 300 can have an external switch 2514 to open the electrical circuit to the battery. Alternatively, the controller can hibernate in a low power mode in which little power is used until a wireless signal is received from the base 400. In such a Low power sleeping mode, an external switch can be eliminated, in that the processor it only wakes up when it receives a signal from the base unit. The signal can be sent by the controller 430 when the sensor 330 or pump is removed from a cradle in the base unit 400. This switch can be released from the closed position simply by lifting the sensor, or by a magnetic proximity switch 2513, or by detecting an interruption in the charging circuit.

Alternative Thermal Measurement Means

[001 70] In additional embodiments, described below with respect to FIG. 26 and FIG.

27A and 27B illustrate there are alternative means to measure temperature of either the vessel interior or the foodstuff therein. A thermal probe may have an extendable portion that is optionally inserted directly in food, or placed in contact with food. As a non-limiting example, the thermal probe 26322a is made of joined linked segments 26322' which can be articulated to make food contact or insertion which terminate in the thermal sensor bearing end portion 26322 intended for food contact or insertion. In contrast, thermal probe 26322b has a rigid end shaft 2722, but a flexible portion 2622 between the penetration in the lid and the rigid end. Either probe can enter the vessel interior through a separate penetration in the lid or via an attachment to the housing 27301. The compressing articulation of the jointed lined segments 26322a, or the re-coiling of portion 26322b permits setting the probe ends 2722 in the foodstuff 1 before sealing the vessel 110 with lid 200. Either thermal probe can have a wired or wireless connection to controller 430..

[001 71 ] A thermal probe can use the main portal in the lid, or an auxiliary portal.

Alternatively, such a thermal probe can extend from the terminal end of a coiled or articulating portion, as well as be at least partially rigid and optionally having a coiled or articulating portion that collapses to store the probe just under the lid and away from food stuffs when it's use is not desired.

[001 72] A shown in FIG. 26, the probe may extend in the wall of the vessel and

connect directly to the base unit 400 via a cable 2300. The left side of FIG. 26 shows such a coiled internal probe, when extended (broken line) the thermal probe is inserted directly in the food stuff 1.

[001 73] It is more preferred that an extending or expanding internal probe also deploy a thermal sensor that is separately able to communicate with the controller 430 to signal the vapor temperature just below the highest point, or otherwise proximal to the penetration in the lid.

[001 74] An internal food probe 26322a or 26322b should be protect from steam to the extent it would cause deterioration in electrical function. The tip of the probe containing a thermo-couple metallic junction or thermistor can be covered with a heat shrinkable cover to make a seal with the insulating wire jacket, with Parylene TM coating. Such a wire jacket on the other end can pass through a sealing gasket in the lid, or be in sealed connection to a portion of the sensor mean 300 that is internal to the penetration in the lid. It should be appreciated that while the end of a thermal probe has a needle shape to penetrate foodstuff 1, it may also deploy a hook, anchor or external stop plate. Such a hook or anchor prevents movement when lid 200 is attached the vessel rim. Sealing of the internal thermal measurement wires can be via a pluggable opening in the lid, so that excess wire comes out of the opening when the lid is set in place. Such excess wire can be slid outside of the vessel via the annular seal. Alternatively, a thermal probe can be built into a food supporting rack. When food is placed on the rack, the probe penetrates the foodstuff 1. The instant inventions ability to rapidly change the cooking temperature environment, and in some embodiment, measure core food temperature , provide for better control of temperature expose gradient within the food stuff. While fixed temperature environments, i.e. convention Sous Vide water bath cooking can be accelerated by cooking at a little bit higher than the desired core temperature, this will produce a gradient in doneness. The gradient will be steeper the higher the bath temperature is raised to reduce cooking time. The instant invention provides a means to accelerate cooking times and considerable flatten such a gradients by and decrease cooking time by a gradual reduction of the temperature difference via the controller 430.

To the extent an internal probe is used, the cooking method can be accelerated by cooking at a higher temperature than the target for a short period. This period can be shortened depending on the consumer willingness to have the outer layers of the food overcooked, which is a rare interior but a well done outside. For examples if the food core temperature is being measured internally, the device controller 430 can calculate a minimum cook time and the associated temperature profile, based on the limitation that a percentage of the surface will not exceed a given temperature; as may be specified by the user via interface 2500, or a wireless transmission to the controller 430 that specifies the same, or a cooking time and temperature profile pre-determined to produce the desired result.

[001 76] In the case of a pre-seared steak, the surface will be well done, so a very high temperature can be used initially, with downward steps in temperature as portion reach the desired core temperature. In such a mode, all control calculation are performed by the base unit controller 430, subject to cooking conditions and recipes entered with the user interface 2500.

[001 77] The thermal measurement means 300 and thermal probe 322 in FIG. 27A and

B has a means to limit penetration in the food and detect such penetration. The penetration is limited by an annular disc 2701 that can be translated and secured in position on the rigid thermal sensor shaft 2722. The translation and setting can be via engaging helical threaded on the disc bore and the shaft, or with a set screw on the side of the disk. The penetration depth is set by the disc 2701, and indicated by the protrusion of an indicating button 2702 from the top of the housing 2730. The button 2702 is connecting via an axial extension to the top of the thermal sensor shaft 2722, but separated from the housing 27301. The top of the thermal sensor shaft 2722 is however coupled to the housing 2730 lby a spring 2703. Hence, once the shaft 2722 is arrested from further penetration by the disc 2701 contacting the foodstuff surface, further downward force (as shown on FIG. 27B) by the user on housing

27301 will deform the spring 2703 causing the housing 27301 to move below the top of the indicating button 2702. The spring 203 can be a leaf spring or coil spring and the like, and the button 2702 can have any position in or adjacent to the housing 27301, but is preferably co-axial with shaft 2722. Alternative Vessels and Vessel Heating

Configurations

[001 78] FIG. 28 through FIG. 32 illustrate alternative embodiments of the vessel and heating sources particularly adapted for low pressure cooking having further inventive characteristics. [001 79] In FIG. 28, the vessel 28110 has an egg like shape with a curvilinear bottom 28111 adapted to be received in the base heating unit 400 with a conforming heater element 28160. This embodiment requires only a small volume of water to fill the lower portion of the vessel 28110 spanned by the heating element 28160. The heater element 28160 is optionally an induction coil or resistance heater, but is preferably curved to match the vessel shape to stabilize the vessel and to provide a large thermal contact area. It has been discovered that the use of a small quantity of water allows the heated vessel to cool quickly from the higher temperature reached to form sufficient water vapor to expel air so that a sufficient vacuum forms on cooling to the cooking temperature. Accordingly, the heater element 28160 preferably has a height along the vessel sidewall that is matched to the vessel volume and curvature. The fill level before use is preferably slightly above this volume to ensure some liquid water remains, should it be desired to obtain a vacuum again after testing or removing cooked foodstuffs. The measurement and transmission of the vessel internal temperature can be via the thermal measurement means described in alternative embodiments.

[001 80] In FIG. 29 illustrates an alternative embodiment of a low pressure cooking vessel 29110 that has a side handle 29150 that provides a means for connecting the thermal probe 29322 to the base unit 400 and controller thereof 430, via cable or wiring 2300. The cable or wiring 2300 is connected to the base unit 400 via a plug and socket connector 2915 that is at the bottom of the handle 29150. When the vessel is placed on the heating element 29160, the plug and socket connector 2915 engages a mating connector 2915' on an upper surface of the base unit 400. An aspect of the vessel and base unit 400 shape preferably aids in the aligned of the plug and socket connector 2915 and 2195' when the handle 29150 is used to dispose the vessel 29100 on the base 400. The heater element 26160 is optionally an induction coil or resistance heater. This embodiment, via the inventive vertical extent of the handle and housing avoids exposed wiring and a wireless transmission of the thermal measurements used by the controller 430 to modulate the power to the heater 26160.

[001 81 ] Alternatively, a thermal sensor 29322' can extends into the vessel via the side wall adjacent to the handle 29150. Lid 29220 is vented at the top with the valve 29301, which can optionally replace the thermal sensor and transmitter

29300, describes with respect to other embodiments, when it is not essential to measure the temperature of the vapor just below lid 29200.

[001 82] In the case of thermal probe 29322 that enters from a sealed penetration in the lid 29200, the signal wire 2300 can connect with the thermal probe 29322 via a hinge 29160 connecting the lid 29200 to the vessel 29100. The signal wiring

2300 from the sensor can be protected by a portion of the lid and hinge elements that is coupled to the side handle 29150. When the thermal probe 29322 is fixed in location on the vessel sidewall or the lid, then thermal sensing means 29300 can be replaced with an ordinary vent member 29201 that seals the penetration in the center of the lid of central lid handle.

[001 83] FIG. 30 illustrates another alternative embodiment of a low pressure cooking vessel 30110 associated with a particular base unit 400 having a de -mating electrical connection via mating plug and socket 3015 and 3015' to a heater element 30160 connected to the bottom of the vessel 30110. A skirt 30165 extends around the bottom of the vessel 30110 to cover the heater 30160 and the socket or plug 3015, as well as the signal wire plug or socket 2915. The heater power and signal connection can also be made with a single co-axial device with 3 or 4 separate connection, or multiple connectors as shown, of which each can be co-axial. When the vessel 31100 is lifted from the base 400 power is disconnected to the heater 29160.

[001 84] FIG. 31 illustrates an alternative embodiment of a low pressure cooking of

FIG. 30 that also deploys a pump means 2200 in the lid. The pump means 2200 is in power and signal connection with the heater base 400 via wiring 2300 that extends through a hinge 29160 connecting the lid 200 to the handle 29150 of the vessel 3110. The wiring path above the lid 200 can be in a housing 31250 that is connects the lid 200 to the hinge 29160. Alternatively, the pump means 2200 can be integrated with the handle 21150 and be in fluid communication with the interior of the vessel 31110 via a penetration in the sidewall adjacent to the handle 21150.

[001 85] As an alternative thermal sensor to those illustrated for the embodiments of

FIG. 28 and 29, the temperature of the external lid and vessel wall surfaces can be measured externally, with the suitability depending on the thermal conductivity of these surfaces.

[001 86] The heating vessel and heater system of FIG. 21-24 and 30 and 31 have the general advantage that the evacuation can occur before the heating stage and thus avoid overheating delicate foodstuffs that might overcook before the steam displaces air in the vessel.

[001 87] It should be appreciated that the embodiments of FIG. 29-31 that include a handle 29150 may also deploy an external pouring spout 29170 for hot water preparation for use in brewing tea and other beverage. The pouring spout 29170 wraps around an exterior portion of the vessel 110 sidewall opposite the handle 2550 but below the rim of the vessel to avoid interference with the gasket 214 sealing the lid at the vessel rim. After removing the lid, tilting the vessel via the handle causes water to pour over the rim into the exterior pouring spout region, and then pour over the lower apex of the spout. A thermal sensor is preferably disposed in either the lid or handle portion, penetrating the vessel sidewall, so that a thermal probe reaches the water level. As in the examples of thermal control for the purposes of cooking food, the water can be boiled and returned to a constant temperature below the boiling point, or alternatively just heated to the desired temperature. Such temperature control of water is useful in different beverage brewing processes in which boiling water is too hot, and detrimental to flavor profile development. Alternative Vessel Shapes

[001 88] To the extent that the vacuum in an embodiment of the vessel is formed by generating and then condensing water vapor, addition embodiment include a means for reducing, measuring and segregating the water from the foodstuffs. [001 89] The vacuum capable vessel may have a water holding pocket in the side or center of the pan, and the foodstuff can be located away from the pocket, or above the pocket being supported by the pocket walls that retain the water, or a removable rack. The top of the walls, or marks thereon, can indicate the quantity of water to be used for cooking. The pan can be configured to heat only this pocket, as for example a limited portion of the bottom of the vessel below the pocket can have a ferromagnetic outer layer for inductive coupling . Foodstuff can be supported above water by ribs in the bottom of the pan. The ribbons can be in different portion of the pan, for examples, the interior bottom edges of the pan could be ribbed and center could be flat. A convention gas or electric range can initially be used to heat the pan or vessel and produce sear marks on meat from the ribs or evenly cook the on the center, with the food placed on the ribs when water is added and the lid is closed to produce steam and expel air.

[001 90] FIG. 32 illustrates an alternative embodiment of the invention in which the vessel 32110 is intended for use in a microwave oven with insertion of the thermal probe 32322 through the lid 32200 via a vacuum sealable gasket 32201. The outer vessel body 32110 is transparent to microwave energy so that the transmitted microwaves heat water 2 at the bottom thereof, creating steam. The vessel has a microwave opaque inner food containing vessel 32111. Water outside this inner vessel 32111 is heated to form steam 3 which expels air. The steam will displace air in the container 32100, so that on slight cooling the lid 32200 will seal to the rim of the container 32100 via the gasket member 214. The food stuff 1 is held in an inner container 3211 having alternative channels 32115 to admit steam and water vapor at the sides, as well as via an at least partially open top 32211. The inner container 3211 is generally opaque to microwaves, that is reflective and/or microwave absorbing, so that the foodstuff 1 is only heated indirectly by water vapor. The temperature of the water vapor is measured by the thermal probe 32322 that penetrates the lid 32200, and connects to the control system of the microwave oven via cable 32240. Accordingly, the microwave oven provides a process controller that in response to the thermal probe 32322 output first heats the water for a sufficient time to create steam 3 and displace the air, and then allow the vessel interior to cool to the cooking temperature. The microwave oven power controller would integrate or be under the control of the process control, which as in other embodiments would a PID or similar control scheme to provide a desired time-temperature profile for cooking. Thermal probes for microwave ovens used to control, display and/or set alarms for reaching a specific temperature are well known. However, they are currently subject to the limitation that the food may cook too fast or unevenly with direct microwave exposure. Vessel configurations that allow for steaming of food, without direct microwave exposure are also known, and disclosed in US Pat.'s 5,558,798, 6,803,551 and 8,772,685, which are incorporated herein by reference. However, these vessels lack a means for vacuum sealing or sealed insertion of a thermal probe, the former being considered as undesirable, such as in the '685 patent.

The use of sub-headings in the Description is not intended to limit features of one embodiment from being combined with features of other embodiments. While the invention has been described in connection with a preferred embodiment, it is not intended to limit the scope of the invention to the particular form set forth, but on the contrary, it is intended to cover such alternatives, modifications, and equivalents as may be within the spirit and scope of the invention as defined by the appended claims.

Claims

We claim:

1) A cooking assembly comprising: a. a heating base having an upper surface for supporting a cookware vessel, in contact with a heater element, and a controller that is responsive to energize the heater element, b. a cookware vessel having a bottom portion adapted to be supported by the upper surface of the heating base, substantially upright sidewalls extending upward there from to terminate at a rim, the sidewalls encircling said bottom portion to form an interior portion capable of retaining a fluid, c. a lid adapted with a gasket to engage said cookware vessel at the rim

thereof to form a vacuum seal therewith, d. a thermal probe that enters an interior portion of the vessel and is in signal communication with the programmable controller, e. a pump in fluid communication with the vessel to reduce the partial

pressure of air in the cookware vessel to 0.3 Bar and less, f. wherein the programmable controller is operative first energize the pump to reduce the partial pressure of air in the vessel to 0.3 Bar and less and then to energize and de-energize the heater to maintain a pre-determined temperature entered into the programmable controller in response to the temperature measured by the thermal probe.

2) The cooking assembly of claim 1 wherein the pump is disposed in the heating base.

3) The cooking assembly of claim 1 wherein the lid has at least one sealable

penetration formed in the surface thereof and wherein the gasket and sealable penetration in the lid are adapted to maintain at least one of an at least partial vacuum and a pressure greater than atmospheric pressure in the interior portion of the vessel. 4) The cooking assembly of claim 1 wherein the thermal probe is in signal communication with the programmable controller via a wireless connection provided by a transmitter disposed in supported engagement with the lid.

5) The cooking assembly of claim 4 wherein the transmitter is powered by a battery and the heater base has a cradle for storing the transmitter with a means for recharging the battery thereof during storage.

6) The cooking assembly of claim 4 wherein the transmitter comprises a processor to calculate a time to transmit based on temperature variation with time.

7) The cooking assembly of claim 1 wherein the pump is co-housed with the thermal probe and is adapted for removable supported engagement with the lid.

8) The cooking assembly of claim 6 wherein the pump is energized via a wired

connection with the base.

9) The cooking assembly of claim 1 wherein the pump is adapted for removable supported engagement with the lid and is in signal communication with the controller and is in fluid communication with the interior portion of the vessel via a sealable penetration of the lid.

10) The cooking assembly of claim 9 wherein the pump is energized via wired

connected with the base.

11) The cooking assembly of claim 1 wherein the lid is connected to the vessel by a hinge and the vessel further comprises a side handle and the connection of the power from the base to the pump is via a wired connection that is disposed within the handle and the hinge.

12) A cooking assembly comprising: a. a heating base having an upper surface for supporting a cookware vessel, in contact with a heater element, and a controller that is responsive to energize the heater element, b. a cookware vessel having a bottom portion adapted to be supported by the upper surface of the heating base, substantially upright sidewalls extending upward there from to terminate at a rim, the sidewalls encircling said bottom portion to form an interior portion capable of retaining a fluid, c. a lid adapted with a gasket to engage said cookware vessel at the rim

thereof to form a vacuum seal therewith, d. a thermal probe that enters an interior portion of the vessel and is in signal communication with the programmable controller, e. a side handle connected to an exterior sidewall of the vessel wherein the side handle provides a means for routing a wired connection of the thermal probe to the programmable controller, f. wherein the programmable controller is operative to energize and de- energize the heater to maintain a pre-determined temperature entered into the programmable controller in response to the temperature measured by the thermal probe.

13) The cooking assembly of claim 12 wherein the lid has at least one sealable

penetration formed in the surface thereof and wherein the gasket and sealable penetration in the lid are adapted to maintain at least one of an at least partial vacuum and a pressure greater than atmospheric pressure in the interior portion of the vessel.

14) The cooking assembly of claim 12 further comprising a pump in fluid

communication with the interior of the vessel.

15) The cooking assembly of claim 14 wherein the pump is energized via a wired connection with the base that is at least partially within the handle. 16) The cooking assembly of claim 14 wherein the pump is adapted for removable supported engagement with the lid and is in signal communication with the controller and is in fluid communication with the interior portion of the vessel via a sealable penetration of the lid. 17) The cooking assembly of claim 12 wherein the programmable controller is

operative to heat the vessel to temperature and a time calculated by the controller to be sufficient to reduce the partial pressure of air in the vessel to 0.3 Bar and less upon further cooling and to energize and de-energize the heater to maintain a pre-determined temperature entered into the programmable controller in response to the temperature measured by the thermal probe.

18) The cooking assembly of claim 17 wherein the programmable controller is

operative to heat the vessel for a time calculated by the controller from a time dependent rise in temperature measured by the thermal probe.

19) The cooking assembly of claim 12 wherein the heating element is attached to an exterior bottom of the vessel and is connected to receive power from the heating base via a de-mating connection having a first connector on an upper surface of the heating base.

20) The cooking assembly of claim 12 wherein the means for routing a wired

connection of the thermal probe to the programmable controller is a de -mating connector having a first connector on a lower surface of the handle.

21) The cooking assembly of claim 20 wherein the de-mating connector of the

thermal probe further comprises a second connector on an upper surface of the heating base for making signal connection with the first connector.

22) The cooking assembly of claim 12 wherein the lid is connected to the vessel via a hinge and the side handle connected to an exterior sidewall of the vessel supports the hinge and the thermal probe that enters an interior portion of the vessel and is connected by a wired connection routed through the hinge and handle. 23) A cooking assembly comprising: a. a vessel having a curvilinear shaped exterior bottom, uprights sides that surround the bottom to extend upward to a rim, b. a lid adapted with a gasket to engage said cookware vessel at the rim

thereof to form a vacuum seal therewith, c. a thermal probe that enters the interior of the vessel, d. a heater base adapted to receive and support the curvilinear shaped

bottom, including; i. a heater element therein having a curvilinear shape that conform to the curvilinear shaped exterior bottom of the vessel, ii. a programmable controller to modulate power to the heater base to heat the vessel is accordance with an output of the thermal probe.

24) The cooking assembly of claim 23 wherein the programmable controller is

operative to heat the vessel to temperature and a time calculated by the controller to be sufficient to reduce the partial pressure of air in the vessel to 0.3 Bar and less upon further cooling, and is further operative to energize and de-energize the heater to maintain a pre-determined temperature entered into the programmable controller in response to the temperature measured by the thermal probe.

25) The cooking assembly according to claim 23 wherein the gasket is operative to be urged downward by the lid when the vessel is evacuated so that the visible portion thereof above the vessel rim is disposed below the vessel rim after evacuation.

26) The cooking assembly according to claim 25 wherein the gasket has an F shape and the sidewall portion of the vessel sidewall below the rim has a curvilinear portion that contacts multiple portions of the F shaped gasket when a vacuum is formed in the interior of the vessel. 27) A cooking assembly comprising: a. a heating base having an upper surface for supporting a cookware vessel, in contact with a heater element, and a controller that is responsive to energize the heater element, b. a cookware vessel having a bottom portion adapted to be supported by the upper surface of the heating base, substantially upright sidewalls extending upward there from to terminate at a rim, the sidewalls encircling said bottom portion to form an interior portion capable of retaining a fluid, c. a lid adapted with a gasket to engage said cookware vessel at the rim

thereof to form a vacuum seal therewith, d. a thermal probe having a means to variably extend into the interior of the vessel for penetration into foodstuffs therein that is in signal

communication with the heater base.

28) The cooking assembly of claim 27 wherein the thermal probe further comprises an external means to display foodstuff penetration.

29) A cooking vessel assembly having: a. an outer cookware vessel that is microware transparent having a bottom portion, substantially upright sidewalls extending upward there from to terminate at an outer rim, the sidewalls encircling said bottom portion to form an interior portion capable of retaining a fluid, b. a lid adapted with a gasket to engage said outer cookware vessel at the outer rim thereof to form a vacuum seal therewith, c. An inner cookware vessel that is at least one of microwave absorbing and microwave reflective, having a bottom portion, substantially upright sidewalls extending upward there from to terminate at an inner rim, wherein the inner cookware vessel is adapted for being seated within the interior portion of the outer cookware vessel and not interfering with the sealed engagement of the lid with the outer rim to form a vacuum. d. at least one of the lid and the outer vessel having a sealable penetration for receiving a thermal probe sealed connection therewith.

30) The cooking vessel assembly according to claim 29 wherein the gasket is

operative to be urged downward by the lid when the vessel is evacuated so that the visible portion thereof above the vessel rim is disposed below the vessel rim after evacuation.

31) The cooking vessel assembly according to claim 30 wherein the gasket has an F shape and the sidewall portion of the vessel sidewall below the rim has a curvilinear portion that contacts multiple portions of the F shaped gasket when a vacuum is formed in the interior of the vessel.

32) The cooking assembly of claim 12 wherein the vessel further comprises a pouring spout that wraps around an exterior portion of the vessel sidewall opposite the handle but below the rim of the vessel to avoid interference with the gasket sealing the lid at the vessel rim. 33) A cooking assembly comprising: a. a heating base having an upper surface for supporting a cookware vessel, in contact with a heater element, and a controller that is responsive to energize the heater element, b. a cookware vessel having a bottom portion adapted to be supported by the upper surface of the heating base, substantially upright sidewalls extending upward there from to terminate at a rim, the sidewalls encircling said bottom portion to form an interior portion capable of retaining a fluid, c. a lid adapted with a gasket to engage said cookware vessel at the rim

thereof to form a vacuum seal therewith, d. a thermal probe that enters an interior portion of the vessel and is in signal communication with the programmable controller via a transmitter, e. wherein the programmable controller is operative to energize and de- energize the heater to maintain a pre-determined temperature entered into the programmable controller in response to the temperature measured by the thermal probe after the pressure is reduced to 0.3 Bar or less.

34) The cooking assembly of claim 33 wherein a battery powers the transmitter.

35) The cooking assembly of claim 33 wherein the heater base has a cradle for storing the transmitter.

36) The cooking assembly of claim 35 wherein a battery powers the transmitter and the cradle for storing the transmitter is a means for recharging the battery thereof during storage.

37) The cooking assembly of claim 34 further comprising a means for recharging the battery connected to the heater base.

38) The cooking assembly of claim 33 wherein the programmable controller is

operative to maintain the pre-determined temperature by applying a series of spaced apart power pulses to the heating element and wherein the maximum temperature rise from each pulse is measured with a thermal probe, and the programmable controller is further operative to modulate the power in each subsequent pulse is response to the variance in temperature associated with prior pulse from the pre-determined temperature.