(a) Compressed yeast contains active yeast plants, which grow quickly, but it spoils rapidly and must be kept in a cool i^lace or purchased fresh each time bread is made. (h) Dry yeast can be kept indefinitely, but the yeast plants are in a less active form and begin to grow only after they have been supplied with food and water. Bread made with this type of yeast does not rise so quickly unless the yeast is first mixed into a sponge and left a few hours until the yeast plants begin to grow rapidly. (c) Liquid yeast is an active form grown at home in a specially prepared mixture, which may or may not contain hops. It may be allowed to ferment spontaneously or may be inoculated with fresh or dried yeast. The latter is a safer method. It will keep for several weeks in a cool place. (3) Salt is added for flavor. Too much salt will retard the action of the yeast. (-I) Fat may be entirely omitted, if preferred. A small amount of lard or vegetable oil is usually added to the dough for tenderness. Fat rubbed over the crust after baking makes it more tender, (5) Sugar is used for flavor and to hasten the growth of the 3^east. Sirup may be used in place of sugar. . (6) Flour.— (a) Wheat flour is most desirable for making yeast bread because it alone of all cereals contains two proteins which form an elastic substance called gluten, when the flour is worked with water, as in the process of making dough. Gluten is the substance which enables the dough to stretch in rising and to hold its shape when baked. The amount and quality of the gluten vary with the kind of wheat and the method of milling. Hard or spring wheat usually is higher in gluten than soft or winter wheat, and is there- fore preferred for making yeast bread. Rye contains one of the proteins necessary to form gluten, but it will not make so large nor so light a loaf. (b) Other materials may be used in yeast bread if com- bined with enough wheat flour to furnish the necessary gluten. Such materials are : (1) Cereals. — Corn, barley, rice, feterita, rye, oats, Kafir, milo. USE AND PREPARATION OF FOOD. 141 (2) Fruits, vegetables, and legumes. — Peanuts, sweet potatoes, buckwheat, taro, potatoes, beans, tapioca, banana. (c) Forms in which other materials may be added: (1) As a flour or fine meal, mixed with the wheat flour. (2) Cooked or scalded and cooled. This method is used with coarse meals or whole grains. In making the bread, allowance must be made for the liquid ab- sorbed. (3) Cooked and mashed to a pulp. This metliod is used for vegetables and for legumes. Allowance must be made for water absorbed in cooking, as mentioned above. (d) Amount of other materials which may be added : (1) A substitution of 25 per cent or less of other ma- terials produces a loaf of standard lightness and only slightly smaller than an all-wheat loaf. (2) A substitution of as much as 50 per cent pro- duces a small heavy loaf, but with a good flavor. More than this amount of substitution is not satisfactory ex- cept in skilled hands. (3) If cooked cereal, vegetable, or legumes are added, no more than 25 per cent should be used, else the bread will be soggy.

AI-modernized reading of the original text

(a) Compressed yeast contains active yeast plants, which grow quickly, but it spoils rapidly and must be kept in a cool place or purchased fresh each time bread is made. (h) Dry yeast can be kept indefinitely, but the yeast plants are in a less active form and begin to grow only after they have been supplied with food and water. Bread made with this type of yeast does not rise so quickly unless the yeast is first mixed into a sponge and left a few hours until the yeast plants begin to grow rapidly. (c) Liquid yeast is an active form grown at home in a specially prepared mixture, which may or may not contain hops. It may be allowed to ferment spontaneously or may be inoculated with fresh or dried yeast. The latter is a safer method. It will keep for several weeks in a cool place. (3) Salt is added for flavor. Too much salt will retard the action of the yeast. (-I) Fat may be entirely omitted, if preferred. A small amount of lard or vegetable oil is usually added to the dough for tenderness. Fat rubbed over the crust after baking makes it more tender, (5) Sugar is used for flavor and to hasten the growth of the 3^east. Sirup may be used in place of sugar. . (6) Flour.— (a) Wheat flour is most desirable for making yeast bread because it alone of all cereals contains two proteins which form an elastic substance called gluten, when the flour is worked with water, as in the process of making dough. Gluten is the substance which enables the dough to stretch in rising and to hold its shape when baked. The amount and quality of the gluten vary with the kind of wheat and the method of milling. Hard or spring wheat usually is higher in gluten than soft or winter wheat, and is therefore preferred for making yeast bread. Rye contains one of the proteins necessary to form gluten, but it will not make so large nor so light a loaf. (b) Other materials may be used in yeast bread if combined with enough wheat flour to furnish the necessary gluten. Such materials are : (1) Cereals. — Corn, barley, rice, feterita, rye, oats, Kafir, milo. (2) Fruits, vegetables, and legumes. — Peanuts, sweet potatoes, buckwheat, taro, potatoes, beans, tapioca, banana. (c) Forms in which other materials may be added: (1) As a flour or fine meal, mixed with the wheat flour. (2) Cooked or scalded and cooled. This method is used with coarse meals or whole grains. In making the bread, allowance must be made for the liquid absorbed. (3) Cooked and mashed to a pulp. This method is used for vegetables and for legumes. Allowance must be made for water absorbed in cooking, as mentioned above. (d) Amount of other materials which may be added : (1) A substitution of 25 per cent or less of other materials produces a loaf of standard lightness and only slightly smaller than an all-wheat loaf. (2) A substitution of as much as 50 per cent produces a small heavy loaf, but with a good flavor. More than this amount of substitution is not satisfactory except in skilled hands. (3) If cooked cereal, vegetable, or legumes are added, no more than 25 per cent should be used, else the bread will be soggy.

Use and preparation of food