Elements of the theory and practice of cookery

194. Batter made light by carbon dioxide produced by union of an acid with a carbonate. — The car- bon dioxide formed in the batter from the union of the baking- soda and the acid in the sour milk expands when heated, mak- ing the griddle cakes light and porous. Moreover, although made with sour milk, the cakes are not sour ; by an experiment we can find out if the soda has anything to do with this. 195. Experiments with acids and alkalies. — A. Add a little sal- soda solution to water in which red cabbage has been boiled.^ What change in color takes place ? Try adding ammonia, a drop of soapsuds, and baking-powder solution to the cabbage water. What effect do they have ? In general, substances that turn cabbage water green are termed alkalies. Baking-soda is an alkaline car- bonate. Taste it. Its slightly soapy taste indicates its similarity to the alkalies used in cleaning. ^ 1 Or use red and blue litmus paper for testing. Alkalies turn red litmus blue ; acids turn blue litmus red. 2 Chemists call washing-soda sodium carbonate^ and baking-soda mono-sodium carbonate. 106 THEORY AND PRACTICE OF COOKERY 196. Experiment B. — Try the effect of vinegar and of sour milk upon cabbage water. Substances that turn cabbage water violet are (or contain) acids. 197. Neutralization. — Acids and alkalies have the power of neutralizing each other (i.e. of destroying each other's characteristic i)roperties). If exactly the right amounts of soda and of sour milk are used, the batter will be neutral ; that is, it will not turn cabbage water either green or violet, and will taste of neither acid, nor soda. (Test some of the batter left in the bowl.) To one pint of thick, recently soured milk use one tea- spoonful of baking-soda. The more acid the milk is, the more soda it requires. Bitter or mouldy sour milk is unfit to be used. Batters and Doughs 198. Quick-bread mixtures are either batters or doughs. Dough means " that which is moistened " ; batter means "that which is beaten." One measure of liquid with one to one and a half measures of flour makes a thin or pour-batter. One measure of liquid to two measures or a little more of flour makes a thick or drop-batter. A mixture stiff enough to be handled on a board is a dough. One measure of liquid to two and two-thirds meas- ures of flour makes a soft dough. One measure of liquid to three or more measures of flour makes a stiff dough. BREAD 107 What kind of a batter is the popover mixture? What kind of a mixture will the recipe for biscuit make ? 199. Ingredients; means of lightening; shortening. — A mixture of flour and water or flour and milk alone would be, when cooked, hard and indigestible. We have found that the introduction of carbon dioxide makes it light and porous, and that, in a watery batter cooked by intense heat, the steam produced puffs the batter up. Eggs are used to stiffen batters. Either the eggs, or the batter after the eggs are mixed with it, is in most cases well beaten, in order to fill the mixture with air, which, expanding, makes it light. (See Muffin Recipes.) With very glutinous flour (§§ 205 and 214) eggs are unnecessary except to make the bread richer. Fat shortens bread, i.e. makes it more tender by sepa- rating the starch-grains of the flour.