(2) To select a variety of desserts so that a different one may be served each time.
DIVISION FIVE
ENERGY-GIVING OR FUEL FOODS,—RICH IN FATS AND OILS
LESSON XXXIV
FAT AS A FRYING MEDIUM
COMPARISON OF FATS AND CARBOHYDRATES.—Fat is a foodstuff. Fat and oil [Footnote 38: Fat and oil are very similar, oil being fat that is liquid at ordinary temperature.] form another great class of energy-giving or fuel foods. In the body, these foods, like carbohydrates, give energy; in fact weight for weight they furnish more than twice as much energy as carbohydrates. There is, for example, about as much fat by weight in one pound of butter as there are carbohydrates in one pound of tapioca. By measurement it has been found that one pound of butter gives to the body almost two and one fourth times as much energy as does one pound of tapioca.
Fats and oils are not only used as food (butter for example) and as constituents of foods (fat in pastry), but as a medium for cooking. The use of fat as a cooking medium follows:
EXPERIMENT 31: TEMPERATURE AT WHICH FATS AND OILS DECOMPOSE OR "BURN."— Into each of 6 test tubes put 2 teaspoonfuls of butter, cottonseed oil, corn oil, beef drippings, lard, and Crisco. Gently heat each one of the fats or oils until fumes first arise from them. Then insert a thermometer [Footnote 39: Care should be taken in using a thermometer in hot fat. It should be allowed to cool before washing.] in each tube and note the temperatures. These are the temperatures at which the various fats decompose. Record these temperatures in your notebook.
How do the decomposing temperatures of fat compare with that of boiling water? Which would be the hotter medium for cooking—hot fat or boiling water?
Which fat reaches the highest temperature before it begins to decompose? If fat is used as a medium of cooking, which of these fats, as far as temperature is concerned, would be the most desirable? Give a reason for your answer.