Sourdough Starter

Sourdough starter is a cultured mixture of flour and water that harbors wild yeast and lactic acid bacteria. It smells gently tangy and yeasty, ferments dough, and builds complex flavor and open crumb in breads and other baked goods; bakers maintain it with regular feedings and it is available as hydrated paste or dehydrated flakes.

Sourdough practice traces to ancient Egypt and spread through Europe, the Middle East, and later North America, with notable regional styles such as San Francisco. Traditional bakeries kept house cultures, and modern home bakers commonly propagate starters from local flour and water.