Steam is a highly efficient heat transfer medium. It carries a great deal of energy that is easily transfers directly to food in commercial cooking equipment like a steamers or as indirectly through a heat transfer surface like the wall of a steam jacketed kettle and then into the food you are preparing.
Steam is water, a liquid, that has been converted to its gaseous state by application of heat energy. Typically, heat energy is measured in BTU’s or British Thermal Units. A BTU is the amount of energy required to raise the temperature of one pound of water by a single degree Fahrenheit at sea level. It takes 180 BTUs to raise the temperature of one pound of water from 32 degrees Fahrenheit to 212 degrees Fahrenheit or to its boiling point. However, to evaporate the same pound of boiling water to the point that it will evaporate takes 970 BTUs. As a result, steam carries with it many times the energy of boiling water. Steam readily gives up that energy load when it condenses back into water as it does upon contact with food. This is why steam is such an efficient method of heating and cooking making it perfect for the busy commercial kitchen.
