This section is from the book "A Manual Of Home-Making", by Martha Van Rensselaer. Also available from Amazon: A Manual of Home-Making.
A discussion of the essential materials used in cakes is given on pages 474 to 477. Following are suggestions on certain accessory materials.*
* Mills, Katherine H. Making Cake. Part I. Cornell Reading-Course for the Farm Home, Bull. 73.
Several types of fruit are commonly used in making cake; first, dried fruits and candied fruits, such as currants, raisins, citron, cherries, pineapple; second, fresh raw fruits, such as blueberries, and cherries; third, cooked fruit pulp, such as applesauce and blackberry jam. As a general rule it may be said that when fruit is used in making cake, the batter will need to be stiffer than for ordinary cake, the stiffness depending on the weight of the pieces of the fruit to be held in place. A cake dough containing raisins will need to be stiffer than one containing blueberries, and a cake dough containing blueberries will need to be stiffer than one made with apple-sauce or jam. The presence of particles of dried fruit increases the difficulties in baking cake, as fruit scorches easily and some of the fruit will be at the surface of the cake. Rich fruit cakes should, therefore, be baked in a very slow oven. This not only prevents scorching, but also improves the flavor, since the fruit flavor blends with that of the other ingredients.
Chocolate contains a hard fat which adds richness to cake, but which tends to make it stiff as it dries out or if the cake is kept in a very cold place. Chocolate cake that is made with sour milk and soda is usually softer and darker in color than that made with sweet milk and baking powder. Chocolate contains starch which thickens the batter, so that less flour is needed for chocolate cake than for white cake. Alkali darkens a chocolate mixture, and a little soda added to the melted chocolate before putting it into the batter will not only darken the cake, but also neutralize any free fatty acid in the chocolate and help to make the cake light. The large amount of soda in some recipes for chocolate cake serves the same purpose.
Cocoa should be substituted for chocolate by weight instead of by measure. In manufacturing cocoa nearly all of the fat has been removed from it, so that cakes made by substituting cocoa in a recipe calling for chocolate are likely to be bready unless a small quantity of additional fat is added (the equivalent of about 1/2 tablespoonful of butter for each ounce, or 1/4 cupful, of cocoa used).
Nuts are lighter than fruit and are not likely to settle to the bottom of the tin; therefore they do not need to be floured. They contain fat, and, when added to rich cake, the amount of fat in the recipe should be decreased in proportion to the richness added by the nuts. From 1 to 1 1/2 tablespoonfuls less of fat to each cupful of nuts is usually sufficient. A good method of preparing nuts for cake is to grind them through the coarse knife of the food chopper. When English walnuts or other nut meats are bought already shelled, they should be washed and dried in the oven before being used.
Cakes made of good materials require no additional flavoring. If flavoring is desired, fresh fruit juices or other fresh flavors are preferable to commercial extracts.
 
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