sourdough

Sourdough is bread leavened with a culture of wild yeast and lactic acid bacteria maintained in a sourdough starter made from flour and water. The starter feeds the dough and creates a tangy flavor from lactic and acetic acids produced during fermentation.

Maintenance involves feeding the starter regularly with fresh flour and water to keep the microbial culture active. It can be kept at room temperature for daily use or refrigerated for longer intervals.

History wise, sourdough was common in many cultures before commercial yeast and remains popular in artisanal baking. The flavor and texture vary by region and flour, with San Francisco sourdough associated with particular lactic bacteria.

Process basics include mixing flour, water, and starter to form dough; allowing bulk fermentation, then shaping and proofing before baking, often with steam. Hydration, or the water-to-flour ratio, commonly ranges from 65% to 80%, affecting crumb and crust.

Flour choice and fermentation influence texture and aroma. Whole-grain and rye can add depth. Fermentation can improve digestibility and flavor, and longer ferments can extend shelf life.

Safety and storage considerations: use a healthy starter; discard if mold or off odors appear. Store starter in a jar, refrigerate for less frequent feedings, and refresh before baking.