ABSTRACT
Sourdough is used as an essential ingredient in the production of wheat and rye bread and mixtures thereof. Sourdough has been used for leavening of bread dough for several hundreds of years, and sourdough bread was made in Egypt as early as 3000 B.C. (1). The sourdough was a piece of dough from the previous baking that was kept until the next baking, when it was mixed with flour, salt, and water to make the bread dough. The intervals between baking could be from 1 day, in bakeries, to 1 month, in home baking. If the time between baking was long, salt could be added to the surface of the sourdough to avoid wrong fermentation. While this piece of dough was saved, lactic acid fermentation took place due to multiplication and metabolic activity of lactic acid bacteria (LAB) originally present in the flour. During this fermentation, selection and multiplication of yeasts from the flour also occurred. The natural content of LAB and yeasts from the sourdough was responsible for the leavening capacity of the bread dough primarily due to their production of carbon dioxide. Yeast from beer or wine production could also be added to the dough to increase the leavening capacity until production of commercial baker’s yeast began during the nineteenth century (2). The sourdough still holds a place of honor in many households throughout the world, and small portions are passed on to the daughters at marriage (2).
