A major food since prehistoric times, it has been made in various forms using a variety of ingredients and methods throughout the world. The first bread was made in Neolithic times, nearly 12,000 years ago, probably of coarsely crushed grain mixed with water, with the resulting dough probably laid on heated stones and baked by covering with hot ashes. The Egyptians apparently discovered that allowing wheat doughs to ferment, thus forming gases, produced a light, expanded loaf, and they also developed baking ovens. Flat breads, the earliest form of bread, are still eaten, especially in much of the Middle East, Asia, and Africa. Raised black bread, common in Germany, Russia, and Scandinavia, is made chiefly from rye.
Lighter rye loaves, with wheat flour added, are popular in the United States.
Other forms of raised breads include rolls and buns, chemically leavened quick breads, and yeast-leavened sweet goods that are rich in sugar and shortening. Although raised bread originally relied upon spontaneous fermentation, bakers learned to produce fermentation with yeast. Specific strains have been developed with useful bread-making qualities, including stability, rapid fermentation capacity, and the ability to withstand high temperatures, all permitting production of a uniform product. Only wheat and rye flours produce the necessary gluten to make raised loaves, and wheat gluten is more satisfactory for this purpose. Other ingredients include liquids, such as milk or water, shortenings of animal or vegetable origin, salt, and sugar.