Originally Posted by foodpump
Look, there a finite amount of ways heat is applied to food--in other words, cooking methods.
You have dry heat cooking methods--radient, convection, etc, and you have moist heat cooking methods, where heat is transferred to the food item through steam, oil, or water.
There are however infinite methods of combining cooking methods.
Thus, s.v. 's method of how heat is applied is poaching--a cooking method; or boiling, another cooking method, in the rare cases of when s.v. Items are cooked at temps above 100c.
Does this clarify things?
There are only two major different ways food can be heated up.
1. By microwave - There is no heat applied in this method. The heat is generated by the food. The food cooks itself.
2. By external thermal energy - It makes no difference what is the heat source, boil, broil, bake, fry, steam, grill, BBQ, poach, braise, sautee, sous vide ------------------------------ Makes no difference to food, call the cooking methods any name, any fancy name.
Temperature is temperature, food is not very smart. It can't tell if the heat is from hot water or from hot charcoal.
Depending on the BTU content (thermal mass, specific heat) of the heat source, air has little BTUs, moving air (convection cooking) has more BTUs, water has more than air.
Depending on the temperature of the heat source, the hotter it is, the more BTUs. However, water and steam cannot be hotter than 212F. And each oil has a different smoking and boiling point. If the oil, air, or water is at say 60F, your food can never get hotter than 60F (essence of SV).
The reason why it make no difference what the heat source is because there is a physical limitation that can not be changed, regardless of the heat source, it is the thermal conductivity of the food. Depending on the food, each has a conductivity index which is a constant. Hot oil, fire, air, water ----- cannot change conductivity . Once the surface of food is heated up, conductivity takes over, heat travels at a specific rate, regardless. Food has no way to tell the identity of the heat source.
Food only knows temperature and how long the temperature is applied, nothing else. Control both exactly and you'll have sous vide.
It is that simple.
Edited by dcarch - 7/23/15 at 5:11am