LESSON CXIV
LEAVENING WITH BAKING SODA, SOUR MILK, AND CREAM OF TARTAR: STEAMED BROWN BREADS
ADDITIONAL LEAVENING FOR SOUR MILK MIXTURES.—Instead of using prepared baking powder as additional leavening for sour milk mixtures (see previous lesson) cream of tartar with sour milk and baking soda may be used. Enough baking soda must be used, however, to neutralize both the sour milk and the cream of tartar. This involves a double reaction:
(a) Baking soda + sour milk —> water + carbon dioxide gas + neutral substance.
(b) Baking soda + cream of tartar —> water + carbon dioxide gas + a neutral substance.
If molasses is used with the sour milk and baking soda, a third reaction occurs:
(c) Baking soda + molasses —> water + carbon dioxide gas + neutral substance.
It has been found that the following proportion of cream of tartar and baking soda is effective in leavening: 1 1/4 _teaspoonfuls of cream of tartar with 1/2 teaspoonful of baking soda._ These quantities of materials are sufficient to leaven 1 cupful of flour. 1 1/2 _teaspoonfuls of cream of tartar with 2/3 teaspoonful of baking soda are required to leaven 1 cupful coarse wheat flour or flour or meal other than wheat._
In determining the quantity of cream of tartar and baking soda to use with mixtures containing sour milk or other acid food, note the quantity of flour (or other cereal) in the recipe. Assuming that 1/2 teaspoonful of baking soda (with the necessary "acid" material) leavens 1 cupful of flour, determine the total quantity of baking soda, which (with the necessary "acid" material) will leaven the flour. Then determine how much of the baking soda will be neutralized by the sour milk or other "acid" food. Assuming that l-1/4 teaspoonfuls of cream of tartar are needed to neutralize 1/2 teaspoonful of baking soda, use enough cream of tartar to neutralize the remainder of the baking soda. For example, if a recipe calls for (among other ingredients) 2 cupfuls flour and 1 cupful of sour milk, 1 teaspoonful of baking soda (with the necessary "acid" material) will be needed to leaven the flour. Since 1 cupful of sour milk will neutralize only 1/2 teaspoonful of baking soda, enough cream of tartar (i.e. 1 1/4 teaspoonfuls) will be needed to neutralize the remainder of the baking soda.
GENERAL SUGGESTIONS FOR STEAMED QUICK BREAD MIXTURES.—A quick bread mixture that is to be steamed should be placed in a covered utensil. If the mold or the can used for steaming has no cover, an oiled paper should be tied over the top. As with all quick breads, the molds for steamed mixtures should be oiled. If the quick bread is a pour batter, the mold should be oiled and then sprinkled with flour. It should never be filled more than two thirds full.