Flour

A good grade of flour should be used for all doughs and batters (p. 495). Pastry flour is better than bread flour for quick-bread mixtures and cake, since it gives a more tender product than does bread flour. Pastry flour may be made at home according to the suggestions on page 490. When other flours are substituted for wheat flour in a recipe, it should be on the basis of weight, since there is much variation in measure.

Liquid

Sweet or sour milk, sweet or sour buttermilk, sweet or sour cream, whey, molasses, water, potato water, rice water, and various other liquids may be used in doughs and batters. Sour milk, sour cream, sour buttermilk, whey, and molasses require soda to neutralize their acid (p. 475). Sour milk gives a texture that is slightly more tender than that produced with sweet milk. Both eggs and fat serve as part of the liquid. An average-sized egg may be regarded as supplying two tablespoons of liquid; fat may be regarded as entirely liquid. This fact must be taken into consideration if changes are made in a standard recipe. If cream is used, its fat-content must be considered (p. 477).

Soda

When baking soda comes in contact with an acid in the presence of moisture, it liberates a gas called carbon dioxide. The acid may be cream of tartar, or such acids as are contained in sour milk or molasses. The amount of soda to be used is determined by the amount of sour milk used and its degree of acidity, and not by the amount of flour as is the case when baking powder is used. Soda may be added in two ways: (1) It may be stirred into the milk, in which case it does not act so decidedly as a leavening agent, but serves to sweeten the milk. In the process some of the gas is liberated and the leavening power is lost to such an extent that it generally becomes necessary to use baking powder as additional leavening agent. (2) The soda may be sifted with the flour, in which case the gas is liberated chiefly during the baking process. When it is added in this way, no additional baking powder is used if the milk is sufficiently sour to require soda in such amount as to give a proportion of 1/2 teaspoon of soda to 1 cup of flour.

No absolute statement can be made, however, as to the correct amounts of soda to use, since sour milk and molasses differ greatly in their degree of acidity. In general it may be said that from 1/4 to 1/2 teaspoon of soda should be used for each cup of sour milk, and more nearly 1/2 teaspoon should be used for each cup of molasses. Experience in cooking with sour milk and soda will best teach correct amounts to use. If soda is added to the milk, the taste may serve as a guide for determining correct amounts, a brackish taste indicating that too much soda has been used, a sour taste indicating that too little has been used. Tests may be made with red and blue litmus paper: if, after the soda has been added, blue litmus paper turns red, the amount of soda has been insufficient to neutralize the acid; if red litmus paper turns blue, too much has been added. If neither red nor blue litmus paper changes color, the acid of the milk has been just neutralized.

Instead of using soda alone as a leavening agent when sour milk or molasses is used as the liquid, some persons choose to use baking powder also in the proportion of 1 teaspoon of baking powder to 1 cup of flour. This is advisable especially if the milk is only slightly sour, and the amount of soda required to neutralize the acid is not sufficient to furnish enough gas to make the mixture light. If eggs are used in the mixture, baking powder is not so necessary.

Baking Powder

Baking powder is a mixture of soda and an acid which will yield a gas when liquid is added. The acid constituent varies with the type of the baking powder. It may be an acid tartrate, a phosphate, or an aluminum salt. Most commercial baking powders contain a third ingredient, starch, which absorbs moisture and so prevents any premature reaction between the soda and the acid. All baking powders, whether homemade or commercial, should be kept in a closely covered jar.

Baking powder is generally used in a mixture in which sweet milk is used as the liquid. Two teaspoons of baking powder will leaven one cup of flour if no eggs are used. If eggs are used, 'the total amount of the baking powder may be decreased 1/2 teaspoon for each egg used.

It is possible to make baking powder at home by combining cream of tartar and soda in the correct proportions. It is not, however, entirely practicable, because of the difficulty in being accurate in measuring and thorough in mixing. The correct proportion, by measure, to combine is 2 1/2 parts of cream of tartar to 1 part of baking soda and 1/2 part of cornstarch; or by weight, 2 2/10 parts of cream of tartar, to 1 part of soda and 1/2 part of cornstarch. The ingredients should be very carefully measured and thoroughly mixed by sifting.

Yeast

Yeast is discussed under yeast breads, page 497.

Eggs

Eggs give firmness of texture, lightness, and richness to batters and doughs. Also they act as a leavening agent by entrapping air as they are beaten. When heated, the albumen, like the gluten of wheat flour, hardens and helps to form a framework to hold up the other ingredients. The tendency is opposite to that of fat, since eggs tend to bind together the ingredients, and fat tends to separate them. Preserved eggs that have a good flavor and odor may be used. One egg may be considered the equivalent of 1/2 teaspoon of baking powder in leavening power.

Shortening

Fats, such as butter, butter substitutes, lard, lard substitutes, tried-out meat fats, chicken fat, and olive and cottonseed oils, are used for shortening. Fat makes the texture of batters and doughs more close-grained and more tender than they would otherwise be. It also improves the flavor in most cases. Mutton fat may be used satisfactorily under certain conditions (page 521). Fat necessitates the use of more leavening, since it oils the particles of flour and makes it easy for the gas to escape. A cake made with a small amount of fat will be porous and will dry out quickly. Too much fat will make the cake heavy and cause it to crumble. If melted fat is added to a cake batter, it should not be hot, since hot fat is likely to make a cake tough, coarse-grained, and heavy.

Since fats vary in their water-content, proper substitution cannot be made by using equivalent amounts.

One cup of butter is equivalent to: 1 cup of lard or lard substitute minus 2 tablespoons; 1 cup of chicken fat; 1 cup of cottonseed or olive oil minus 2 tablespoons.

If cream is used in place of milk, the fat-content must be allowed for in measuring the shortening. One cup of 18 per cent cream is equivalent to 3/4 cup of milk plus 3 1/2 tablespoons of fat. One cup of 40 per cent cream is equivalent to 1/2 cup of milk plus 7 1/2 tablespoons of fat.

Sugar

Sugar gives flavor to a mixture. It also acts as a liquid. A fine granulated sugar gives a better texture than does a coarse sugar. Powdered sugar is sometimes used for a very close-grained cake. If either powdered or brown sugar is used in place of granulated, the substitution should be made by weight, not measure. Molasses is used in some recipes for part of the sugar as well as part of the liquid. Corn sirup may be used in the same way; however, to give sufficient sweetness it should generally be combined with some sugar or molasses. Too much sugar results in a heavy, coarse-grained texture, or a gummy product.