Sourdough-the special type of bread

Sourdough is a type of bread produced by a long fermentation of dough using naturally occurring yeasts and lactobacilli. In comparison with breads made with cultivated yeast, it usually has a mildly sour taste because of the lactic acid produced by the lactobacilli. Sourdough breads are made with a sourdough starter (which differs from starters made with baker's yeast). The starter cultivates yeast and

lactobacilli in a mixture of flour and water, making use of the microorganisms already present on flour; it does not need any added yeast. A starter may be maintained indefinitely by regular additions of flour and water. Some bakers have starters several generations old, which are said to have a special taste or texture. It is possible to obtain existing starter cultures to begin a new one. At one time, all yeast-leavened breads were sourdoughs. The leavening process was not understood until the 19th century, when yeast was first identified. Since then, strains of Saccaromyces cerevisiae have been bred for their reliability and speed of leavening and sold as "baker's yeast". Baker's yeast was adopted for the simpicity and flexibility it introduced to bread making, obviating the lengthy cultivation of a sourdough starter. While sourdough breads survived in some parts of Europe, throughout most of the U.S., they were replaced by baker's yeast. Recently there has been a revival of sourdough bread in artisan bakeries. There are other ways of sourdough baking and culture maintenance. A more traditional one is the process that was followed by peasant families throughout Europe in past centuries. The family (usually the woman was in charge of breadmaking) would bake on a fixed schedule, perhaps once a week. The starter was saved from the previous week's dough. The starter was mixed with the new ingredients, the dough was left to rise, and then a piece of it was saved (to be the starter for next week's bread). The rest was formed into loaves that were marked with the family sign (this is where today's decorative slashing of bread loaves originates from) and taken to the communal oven to bake. These communal ovens over time evolved into what are known today as bakeries, when certain people specialized in bread baking, and with time enhanced the process so far as to be able to mass produce cheap bread for everyone in the world.