When using SousVideMagic, commercial rice cookers are always recommended for their better heat transfer characteristics.

To understand why, we need to a have a brief lesson in thermodynamics.

Cooking food is all about transfer of heat and there are three modes of heat transfer: Conduction, Convection and Radiation.

Conduction involves the transfer of heat by the interactions of atoms or
molecules of a material through which the heat is being transferred. In our case, it is the thermo transfer conducted from heated water to food pouches.

Convection involves the transfer of heat by the mixing and motion of macroscopic portions of a fluid.  In our case, the only natural convection we get from a rice cooker is its natural rising of heat from the bottom heater.

Radiation, or radiant heat transfer, involves the transfer of heat by electromagnetic radiation that arises due to the temperature of a body. In our case, the heated lid and side wall of the vessel  radiate heat throughout the vessel.

Take the 12L Tiger rice cooker for example.

Conduction- Tiger 12L cooker does a much better job than scientific water baths and baths heated by immersion  heater circulators. It is a very well insulated vessel and with surround heat technology, there is little heat loss, thus making rate of heat transfer (heat flux) very efficient.

Convection -  With the aid of artificial stirrers/agitators, scientific water baths and immersion heater circulators win on this mode of heat transfer. Rice cookers do get some natural convection due to bottom heating, that explains why we recommend rice cookers over slow cookers (side heating).

Radiation - Since rice cooker's heat is being delivered surrounding the vessel, there are helpful amount of heat radiation to make heat transfer better. The other baths get little marks for this form of heat transfer.

What matters is the end result of the cooking and rice cookers give you better overall heat transfer characteristics. In due time, laws of thermodunamics and nature of sous-vide's long cooking are on our side, heat will reach homogeneousness throughout the whole vessel  including the food whether you have the water being agitated constantly or not.

For short time (less than 30 minutes) cooking, baths with agitator can reach homogeneousness temperature faster and keep it that way as long as it is stirring. But for long term cooking and if you cook at core-temperature, your food will always get cooked properly with even doneness throughout the whole volume of the food item with or without artificial agitating..

That's why we always recommend cooking at core temperature using the SousVideMagic approach. Even heat is not distributed homogeneously initially, but cooking at core temperature you can never over-cook the food, so different parts of the food item will all reach the same desired core temperature eventually. Cooking at core temperature is very foolproof for even doneness.

Stirring the water will undoubtedly make bath temperature reaches homogeneousness sooner. It is very useful for short term sous-vide cooking like cooking seafood dishes for less than 20 minutes. But if you are cooking beef ribs for 36 hours you are wasting lot of energy by stirring the bath when you don't really need it.

If you look at sous-vide equipment companies around the world, most of them are basically off-shoots  from their scientific water bath and heater circulator business. This way they can market their offerings to food service market better.

The Fresh Meals Solutions Company is a solution oriented company, created from ground up to serve the food service industry. If you buy from us, you will become clients of FMS with privileges like enjoying our lifetime support and sharing our expertise and experience in innovative cooking technologies. We have in house cuisine production, testing and training facilities. We sleep and breath food. In short, we understand your language, needs and problems, so unique culinary solutions can be found and implemented.

We OEM the best products from all over the world meeting our exact specifications and quality requirements.

For local Toronto market, we sell freshly cooked  gourmet dishes packed for the home and restaurant markets.

We recommend commercial rice cookers for sous-vide cooking, because

Slow cookers, although they can be controlled by SousVideMagic and cooked many good sous-vide dishes, their performance are not as good as rice cookers, because their baths are small, heaters are side wall mounted, thick ceramic pots make stable  temperature control very hard to achieve, and not well insulated for efficient heat transfer. But they are cheap and readily available and very good for long term (over four hours) cooking.

The rice cookers we sell  are fully tested with SousVideMagic and tuned (PID settings) together for optimal performance.

Most of our rice cookers are of commercial quality and not readily available in some North America regions. They are all priced competitively.

Yes, we sell freshly cooked gourmet food for the local Toronto market. We are well-situated at the famed Kesington Market where we can buy fresh seasonal ingredients just stone-throw away 365 days a year.

Soon, we will launch "Fresh Meals Pak Solutions" program. Stay tuned for our official annoucement on February 22, 2008.

We practice what we preach and we love to cook, just like you.

Question:  Sous-vide cooking is about low temperature cooking, are you concerned about food safety issues related to sous-vide style cooking?

Answer: Yes, we are always concerned about food safety issues and hygiene practices when we cook food for other people to eat. Not just for sous-vide style cooking, but cooking in general.  There are a few misconceptions regarding sous-vide cooking:

Yes, we are very concerned about one thing- if sous-vide cooking becomes popular and wide-spread usage made possible by cheaper sous-vide technologies like SousVideMagic, and is moving into consumer arena, potential food safety abuses of sous-vide practices are more likely to occur. That's why we started wikisousvide.com aka sousvide.wikia.com aka freedomcookery.com, a community portal to focus on safety issues and definitive sous-vide settings, so all sous-vide practitioners can share their concerns, experiences and expertises.

The word "Freedomcookery" was coined by Pierre de Serres, a French Canadian food scientist, who in 1983 started The Freedomcookery Company in Toronto to sell Smartpot and preach the Freedomcookery Principle. Smartpot concept is very similar to our SousVideMagic approach. Unfortunately, Pierre was 25 year ahead of its time.

Pierre's basic message was:

"Time is the essence of conventional cooking. Temperature is the essence of Freedomcookery. When one cooks with precise temperature control, his/her can achieve freedom from time constraints. Furthermore, each type of food has its optimal cooked temperature zone for best culinary values (texture, taste and nutrition) and if held at cooked  temperature after cooking, food can not overcook from a temperature perspective, but only make safer and tenderer."

One important assumption on the above principle is that from a food safety point of view the temperature you are cooking and subsequently holding at is within safety temperature zone for that specific food item.

It was a profound concept and even today it is hardly understood. 

I first came across this article published in Gremolata.com on  Paula Wolfert's Search of Pierre de Serres.

Paula Wolfert is the famed cook book writer who came across Pierre de Serres' work in the 80s and wanted to write an article on Pierre.

The ending is that Pierre de Selles passed away in the late 90s without realizing his dream.

Like Paula I was looking for Pierre too,  and  I asked David to help to locate him. David Kingsmill was the Toronto Star's food writer who wrote a series of articles on Pierre's works in the early 80s. David then asked  Malcolm of Gremolata to help out and this is what Malcolm said:

Freedomcookery is really sous-vide cooking.

Our main product right now is SousVideMagic(SVM), which is a microprocessor based electronic enabling device for controlling temperature of off-the-shelf rice cookers/slow cookers to cook sous-vide; it is so affordable that any sous-vide practitioners who want to cook sous-vide can now find a practical and economical way to do so.

Now, because of SVM's low cost entry point, we see there are many market opportunities::

Yes, SousVideMagic (SVM) is safe to use if you follow the equipment usage instructions & safety warnings in the User Manual. Pay special attention to your cooker's heater size your SVM model can handle.

From a food safety's point of view, SVM is just as safe as your regular oven. You must aware and understand food temperature danger zones and cook food to core temperature recommended by your local food safety regulators.

SousVideMagic is like driving an automobile, you are in total control and must obey government regulated food safety rules, equipment safety rules and high hygience standards. If you do it right, the results will be amazing and at the same time safe.

Q: I understand that most professional chefs use scientific water baths and immersion heater circulators to cook sous-vide, are they the right kind of cooking appliances to cook sous-vide?

A: The most important requirement to cook sous-vide is precise temperature control over the the water bath's temperature and even distribution of heat throughout the whole bath. Yes, the equipments you just mentioned can do a very good job. The only problem is the costs of those equipments. They are originally designed for the scientific lab market where high costs are more tolerated and justified. In some cases, they often over-killed for their unintended applications.

A word of caution on old scientific baths and immersion heater circulators: most of these equiptments were deposed for good reasons, either they are not performing to specifications or they were just plain too old and their life spans are numbered.