Science in the Kitchen / A Scientific Treatise On Food Substances and Their Dietetic Properties, Together with a Practical Explanation of the Principles of Healthful Cookery, and a Large Number of Original, Palatable, and Wholesome Recipes

by E. E. Kellogg

Stone Metate.

What is usually termed unfermented bread, however, is prepared with flour and liquid, to which shortening—of some kind is added, and the whole made light by the liberation of gas generated within the dough during the process of baking. This is brought about either by mixing with the flour certain chemical substances, which, when wet and brought into contact, act upon each other so as to set free carbonic acid gas, which expands and puffs up the loaf; or by introducing into the dough some volatile substance as carbonate of ammonia, which the heat during baking will, cause to vaporize, and which in rising produces the same result.

Carbonic acid gas maybe for this purpose developed by the chemical decomposition of bicarbonate of potassa (saleratus), or bicarbonate of soda, by some acid such as sour milk, hydrochloric acid, tartaric acid, nitrate of potassa, or the acid phosphate of lime.

The chemical process of bread-raising originally consisted in adding to the dough definite proportions of muriatic acid and carbonate of soda, by the union of which carbonic acid gas and common salt were produced. This process was soon abandoned, however, on account of the propensity exhibited by the acid for eating holes in the fingers of the baker as well as in his bread pans; and a more convenient one for hands and pans, that of using soda or salaratus with cream of tartar or sour milk, was substituted. When there is an excess of soda, a portion of it remains in the loaf uncombined, giving to the bread a yellow color and an alkaline taste, and doing mischief to the delicate coating of the stomach. Alkalies, the class of chemicals to which soda and salaratus belong, when pure and strong, are powerful corrosive poisons. The acid used with the alkali to liberate the carbonic-acid gas in the process of bread-making, if rightly proportioned, destroys this poisonous property, and unites with it to form a new compound, which, although not a poison, is yet unwholesome.

We can hardly speak too strongly in condemnation of the use of chemicals in bread-making, when we reflect that the majority of housewives who combine sour milk and salaratus, or cream of tartar and soda, more frequently than otherwise guess at the proportions, or measure them by some "rule of thumb," without stopping to consider that although two cups of sour milk may at one time be sufficiently acid to neutralize a teaspoonful of saleratus, milk may vary in degree of acidity to such an extent that the same quantity will be quite insufficient for the purpose at another time; or that though a teaspoonful of some brand of cream of tartar will neutralize a half teaspoonful of one kind of soda, similar measures will not always bring about the same result. Very seldom, indeed, will the proportions be sufficiently exact to perfectly neutralise the alkali, since chemicals are subject to variations in degree of strength, both on account of the method by which they are manufactured and the length of time they have been kept, to say nothing of adulterations to which they may have been subjected, and which are so common that it is almost impossible to find unadulterated cream of tartar in the market.

Baking powders are essentially composed of bicarbonate of soda and cream of tartar, mixed in the proper proportions to exactly neutralize each other, and if they were always pure, would certainly be as good as soda and cream of tartar in any form, and possess the added advantage of perfect proportions; but as was demonstrated not long ago by the government chemist, nearly every variety of baking powder in the market is largely adulterated with cheaper and harmful substances. Alum, a most frequent constituent of such baking powders, is exceedingly injurious to the stomach. Out of several hundred brands of baking powder examined, only one was found pure.

Even when in their purest state, these chemicals are not harmless, as is so generally believed. It is a very prevalent idea that when soda is neutralized by an acid, both chemical compounds are in some way destroyed or vaporized in the process, and in some occult manner escape from the bread during the process of baking. This is altogether an error. The alkali and acid neutralize each other chemically, but they do not destroy each other. Their union forms a salt, exactly the same as the Rochelle salts of medicine, a mild purgative, and if we could collected from the bread and weigh or measure it, we would find nearly as much of it as there was of the baking powder in the first place. If two teaspoonfuls of baking powder to the quart of flour be used, we have remaining in the bread made with that amount of flour 165 grains of crystallized Rochelle salts, or 45 grains more than this to be found in a Seidlitz powder. It may be sometimes useful to take a dose of salts, but the daily consumption of such chemical substances in bread can hardly be considered compatible with the conditions necessary for the maintenance of health. These chemical substances are unusable by the system, and must all be removed by the liver and excretory organs, thus imposing upon them an extra and unnecessary burden. It has also been determined by scientific experimentation that the chemicals found in baking powders in bread retard digestion.

Gem Irons.