213. While baking powder is universally used for biscuits and cake, it is seldom, if ever, used for bread, because it does not furnish sufficient gas to lighten the tough heavy mass of bread dough. Then, too, most people prefer the taste of yeast-raised bread. There is a reason for this widespread preference, but to understand it, we must go somewhat far afield, and must study not only the bread of to-day, but the bread of antiquity, and the wines as well. If grapes are crushed, they yield a liquid which tastes like the grapes; but if the liquid is allowed to stand in a warm place, it loses its original character, and begins to ferment, becoming, in the course of a few weeks, a strongly intoxicating drink. This is true not only of grape juice but also of the juice of all other sweet fruits; apple juice ferments to cider, currant juice to currant wine, etc. This phenomenon of fermentation is known to practically all races of men, and there is scarcely a savage tribe without some kind of fermented drink; in the tropics the fermented juice of the palm tree serves for wine; in the desert regions, the fermented juice of the century plant; and in still other regions, the root of the ginger plant is pressed into service. The fermentation which occurs in bread making is similar to that which is responsible for the transformation of plant juices into intoxicating drinks. The former process is not so old, however, since the use of alcoholic beverages dates back to the very dawn of history, and the authentic record of raised or leavened bread is but little more than 3000 years old. 214. The Bread of Antiquity. The original method of bread making and the method employed by savage tribes of to-day is to mix crushed grain and water until a paste is formed, and then to bake this over a camp fire. The result is a hard compact substance known as unleavened bread. A considerable improvement over this tasteless mass is self-raised bread. If dough is left standing in a warm place a number of hours, it swells up with gas and becomes porous, and when baked, is less compact and hard than the savage bread. Exposure to air and warmth brings about changes in dough as well as in fruit juices, and alters the character of the dough and the bread made from it. Bread made in this way would not seem palatable to civilized man of the present day, accustomed, as he is, to delicious bread made light and porous by yeast; but to the ancients, the least softening and lightening was welcome, and self-fermented bread, therefore, supplanted the original unleavened bread.