Sourdough Starter

right|thumb|250px|Sourdough starter

Sourdough is generally considered wild yeast, though it is actually a mixture of yeast and lacto-bacteria that together form the flavor of sourdough. The yeast however is the leavening, and thus more important for cooking.

The flavor and nature of a given sourdough depends strongly on the location. The famous San Francisco sourdough grows only in (and near) the city of San Francisco; if taken elsewhere the local yeasts and bacteria