Helpers that have stayed here at Ironbark Grange would know that we have always had a passion for good food. Australian Masterchef (the TV show) has been watched enthusiastically here and has inspired our family and helpers to create food that is beyond our usual experience to our great enjoyment.
In MasterChef, cooking “Sous Vide” is a regular feature, but the equipment is expensive. So we built our own. The PID Controller is described in a separate post in this blog. In addition to the controller, I purchased a two bin (gastranome) bain marie for the water bath.
This particular bain marie has the element under the water tank so hot spots inside the tank (which is insulated) are minimised. To further separate the cryovac bags from the element at the bottom of the tank, we placed a plastic mat on the floor of the tank. Together with the PID controller the system works very well.
In most Sous Vide systems, a water pump is used to keep the water temperature profile very even. In this system, the water temperature profile appears to be about one degree, which is good enough for our use.
Sous Vide is French for under vacuum. The following is an edited version from Wikipedia.
The food to be cooked is sealed (usually under vacuum) in a cryovac bag or equivalent and then immersed into a precisely controller bath of water. While not suitable for everything, there are definite advantages to this cooking method.
The use of temperatures much lower than for conventional cooking is an equally essential feature of sous-vide, resulting in much higher succulence: at these lower temperatures, cell walls in the food do not burst.In the case of meat cooking, tough collagen in connective tissue can be hydrolyzed into gelatin, without heating the meat’s proteins high enough that they denature to a degree that the texture toughens and moisture is forced out of the meat.
In contrast, the sous-vide technique to cook vegetables at a temperature below the boiling point of water allows vegetables to be thoroughly cooked (and Pasteurized, if necessary) while maintaining a firm or somewhat crisp texture.
By placing the food in a water bath whose temperature is set at the desired final cooking temperature of the food, overcooking can be avoided, because the food cannot get hotter than the bath it is in. In conventional high-heat cooking, such as oven roasting or grilling, the food is exposed to heat levels that are much higher than the desired internal cooking temperature; the food must be removed from the high heat prior to its reaching the desired cooking temperature. If the food is removed from the heat too late, overshoot occurs, and if it is removed too early, undercooking results. As a result of precise temperature control of the bath and the fact that the bath temperature is the same as the target cooking temperature, very precise control of cooking can be achieved. Additionally, temperature, and thus cooking, can be very even throughout the food in sous-vide cooking, even with irregularly shaped or very thick items, given enough time.
One limitation of sous-vide cooking is the fact that browning (Maillard reactions) happens at much higher temperatures (above the boiling point of water). The flavors and “crust” texture developed by browning are generally seen as very desirable in the cooking of certain types of meat, such as a steak. The flavors and texture produced by browning cannot be obtained with only the sous-vide technique. In some cases, meats and other foods cooked with the sous-vide technique will be browned either before or after being placed in the water bath. This secondary browning is done briefly, and sometimes at higher heat than normally used, so as to affect only the surface of the food and to avoid overcooking the interior.