Principles of cooking

Whites of eggs are beaten with an egg beater to entangle or inclose air. To estimate the amount of air inclosed by beating, note the amount of space occupied in the bowl by one egg white before you start to beat it, and then note the change in volume after the white has been beaten until stiff and dry. Unlike water, air does not require a great amount of heat for expansion. Albumin does not require a strong | heat for coagulation, — about 170° F., — and it is toughened _ by too high a temperature. When air, inclosed in eggs, is used as a leavening agent, the food should be cooked at a low temperature. LEAVENING AGENTS — Eccs AND AIR Omelet.— Three eggs, three tablespoons of water, one fourth teaspoon of salt. Separate yolks from whites. ae EE Beat yolks until thick. Beat whites until stiff and dry. Add water and salt to yolks, and fold in the whites. Put one tablespoon of butter in the omelet pan, turn in the egg mixture, and cook slowly. When well puffed out, place in the oven to finish cooking. Whites and yolks of eggs are beaten separately, and the whites are beaten stiff so as to inclose as much air as possible. The omelet is cooked with slow heat to expand the air and coagulate the albumin at as low a temperature as possible (170° F). Intense heat toughens the albumin and coagulates it too soon, there is no expansion of air, and the omelet is tough and flat. - LEAVENING AGENTS — SODA AND Sour MILK When two substances like sodium bicarbonate (soda) and sour milk are mixed together, a chemical change takes place and new substances unlike either of them are formed. One of these substances formed is’a gas, carbon dioxide (CO;), which expands when heated and. makes, food light and porous. When an acid and an’ alkali brought together, one tends. to neutralize ‘Or destroy the characteristic properties of the other. ‘The acid, sour milk, neutralizes the alkali, soda, and no taste of either is left in the food. They are used to form the gas CO: so as to make the food light. This gas is formed as soon as the substances are brought together. It expands when heated, and enough heat must be applied to set the walls of gluten so that the bubbles will not collapse. .When hot water is added to soda (NaHCOs), the gas CO, is given off, but the soda is not neutralized, and the food to which it is added has a bitter taste. It is better to sift the soda into the flour, rather than add it to the sour milk, because when the gas forms so quickly, some is lost before the mixture is put in the oven. Just enough alkali and acid are used to neutralize each other. This can be determined by the use of litmus paper. One half teaspoon of soda neutralizes one cup of sour milk. Other acid substances may be used in place of sour milk, as buttermilk, molasses, and lemon juice. BATTERS AND DoUGHS A mixture of flour and liquid is called either a batter or a dough, depending on the proportion of liquid to flour. Batters consist of from one to two measures of flour to one measure of liquid, and are named either pour or drop batters according to the amount of flour used. Doughs_ consist of from two and one half to three and one half measures of flour to one of liquid, and they are classed as soft and sti pougie. «- Biscuit is a Sus dough; bread is a stiff dough. -