Emulsion. — When fat is divided into minute globules which are held in suspension in a liquid, it is said to be in emulsion. This is a physical state and is readily broken down. The most perfect example of an emulsion is the suspension of the fat globules in fresh milk. The emulsion is but temporary and the fat rises to the surface in the form of cream. FATS — FRYING, AND PASTRY 145 Saponification. — When fat is heated with a strong alkali, it is split up into fatty acid and glycerine, the alkali uniting with the acid and forming a soap, and the glycerine being set free. This reaction is called saponification and may be expressed by the following formula : sodium sodium palmatin + hydrate = palmitate + glycerine 3i02)3 + 3NaOH = 3NaCi6H3i02 + C3H5(OH)3 The soap is soluble in water. This reaction is made use of in household cleaning when a strong alkali as soda, lye, borax, etc., is added to " cut the grease." An excellent soap may be made in the household from fats left in cooking combined with a strong alkali, such as concentrated lye. All fats or drippings left from cooking should, therefore, be saved for soap making. Full directions for making soap are given with the lye purchased for soap making. FRYING Frying is cooking by rmmersion in hot fat at a tempera- ture of from 350° to 400° F. Lard, olive oil, beef suet, beef drippings, or some commercial forms of fat may be used. The fat should be so hot that it will instantly coagulate the albumen on the outside of the article, forming a coating to keep the fat from soaking in. All articles which do not contain egg in sufficient quantity must be rolled in fat-proof coating. Lard boils at 585° F., so for cooking purposes fat does not boil. The ebullition which takes place is due to water in the article fried being converted into steam. Too many articles should not be placed in the fat at one time, as they will cool the fat. The articles should not be too cold, as that will also cool the fat. All fried food should be perfectly drained by holding over the kettle of fat and 146 DOMESTIC SCIENCE shaking gently, and then laid on brown paper. Raw potato absorbs the unpleasant odors or gases of fat, and collects some of the sediment, so a few slices should be put in both before and after frying. After using fat, allow it to cool slightly, then pour it through a cheesecloth put over a strainer. It may thus be used several times. When several articles are to be fried, fry them in the follow- ing order : potatoes, batter mixtures, breaded articles, fish. Objections to Frying as a Method of Cooking. 1. Articles may be grease-soaked. 2. High temperature necessary for frying splits fat up into fatty acid and glycerine. Fatty acid is irritating to organs of digestion. Glycerine is farther split up by heat into acrolein, which gives the disagreeable odor to hot fat and which is also very irritating to the mucous membranes of the digestive organs. Burning Point. — The higher the burning point of a fat, the more valuable is the fat for frying purposes, as it will retain a greater amount of heat before it carbonizes. Butter has a low burning point, hence carbonizes easily and is a poor fat to use for frying.

AI-modernized reading of the original text

Emulsion. — When fat is divided into minute globules which are held in suspension in a liquid, it is said to be in emulsion. This is a physical state and is readily broken down. The most perfect example of an emulsion is the suspension of the fat globules in fresh milk. The emulsion is but temporary and the fat rises to the surface in the form of cream. Saponification. — When fat is heated with a strong alkali, it is split up into fatty acid and glycerine, the alkali uniting with the acid and forming a soap, and the glycerine being set free. This reaction is called saponification and may be expressed by the following formula : sodium sodium palmatin + hydrate = palmitate + glycerine 3i02)3 + 3NaOH = 3NaCi6H3i02 + C3H5(OH)3 The soap is soluble in water. This reaction is made use of in household cleaning when a strong alkali as soda, lye, borax, etc., is added to " cut the grease." An excellent soap may be made in the household from fats left in cooking combined with a strong alkali, such as concentrated lye. All fats or drippings left from cooking should, therefore, be saved for soap making. Full directions for making soap are given with the lye purchased for soap making. FRYING Frying is cooking by immersion in hot fat at a temperature of from 350° to 400° F. Lard, olive oil, beef suet, beef drippings, or some commercial forms of fat may be used. The fat should be so hot that it will instantly coagulate the albumen on the outside of the article, forming a coating to keep the fat from soaking in. All articles which do not contain egg in sufficient quantity must be rolled in fat-proof coating. Lard boils at 585° F., so for cooking purposes fat does not boil. The ebullition which takes place is due to water in the article fried being converted into steam. Too many articles should not be placed in the fat at one time, as they will cool the fat. The articles should not be too cold, as that will also cool the fat. All fried food should be perfectly drained by holding over the kettle of fat and shaking gently, and then laid on brown paper. Raw potato absorbs the unpleasant odors or gases of fat, and collects some of the sediment, so a few slices should be put in both before and after frying. After using fat, allow it to cool slightly, then pour it through a cheesecloth put over a strainer. It may thus be used several times. When several articles are to be fried, fry them in the following order : potatoes, batter mixtures, breaded articles, fish. Objections to Frying as a Method of Cooking. 1. Articles may be grease-soaked. 2. High temperature necessary for frying splits fat up into fatty acid and glycerine. Fatty acid is irritating to organs of digestion. Glycerine is further split up by heat into acrolein, which gives the disagreeable odor to hot fat and which is also very irritating to the mucous membranes of the digestive organs. Burning Point. — The higher the burning point of a fat, the more valuable is the fat for frying purposes, as it will retain a greater amount of heat before it carbonizes. Butter has a low burning point, hence carbonizes easily and is a poor fat to use for frying.

A textbook of domestic science for high schools