_Cake._--There are other methods of making food "light" besides putting yeast into it. Two of these are commonly used in making cake and fancy breads. Sponge cakes are made light by beating air into the eggs used. Cakes which contain butter, and breads which contain no yeast are made light with baking powder, which is a mixture of soda and cream of tartar, or with soda and cream of tartar put in separately. Soda is an alkali; cream of tarter is an acid. A combination of the two liberates carbonic acid gas to raise the cake and also counteracts the poisonous properties of the soda. Three rounded teaspoonfuls of baking powder produce the same effect as one level teaspoonful of soda and two rounded teaspoonfuls of cream of tartar. Therefore, if a receipt calls for soda and cream of tartar and we have only baking powder, or vice versa, we may use one for the other if we remember this equality.
One frequently finds soda and not cream of tartar called for in receipts in which sour milk or molasses is required. In such cases the acid in the milk or in the molasses will take the place of that usually furnished by cream of tartar. Soda and cream of tartar, or baking powder, should be put into the flour before it is sifted, they are thus thoroughly mixed with it and also sifted.
The ingredients of fancy breads and cake must be mixed in ways which will not interfere with the means by which they are made light.
It is usually a good plan when mixing muffins, gems, Sally Lunn or anything of the kind which does not require kneading, to put all the dry ingredients together in one bowl, all the wet ones together in another bowl, then to stir the wet ones into the dry ones and if there are eggs in the mixture fold in the beaten whites last.
Whites of eggs are nearly always the last thing to be put into any mixture, because if they are moved about more than is necessary to get them in, much of the air in them will be lost.
The ingredients of cake are usually mixed in the following order: butter and sugar beaten together to a creamy consistency; beaten yolks of eggs; milk or water and flavouring; flour and baking powder; whites of eggs.
The order for mixing a sponge cake is the same except that some of the ingredients mentioned in this list will be omitted.