Surdegstart

Surdegstart, or surdegstart in Swedish, is a culture of wild yeast and lactic acid bacteria used to leaven bread. It is created by fermenting a mixture of flour and water, drawing microorganisms from flour and the surrounding environment. When active, it becomes bubbly and capable of energizing dough through fermentation.

The microorganisms in a surdegstart produce carbon dioxide, which leavens bread, and acids such as lactic and acetic acid, which contribute to a characteristic tang. The exact flavor and texture depend on the feeding routine, temperature, and flour type, which influence the balance between milder and sharper sour notes.

Getting started typically involves mixing equal parts by weight of flour and water and leaving the mixture at room temperature. After 24 hours, discard a portion and feed with fresh flour and water, repeating daily. Within three to seven days the starter should be bubbly, smell pleasantly sour, and rise in size between feedings.

Maintenance requires regular feeding to keep the culture healthy. At room temperature, feed daily or twice daily. In cooler conditions, the starter can be stored in the refrigerator and fed weekly, with a plan to refresh it before baking.

Readiness and use: A starter is ready when it reliably doubles in size within a few hours of feeding and shows a balanced sour aroma. It can replace commercial yeast in many bread recipes, often improving flavor and crumb, depending on the formulation.

Storage and safety: Store a starter in the refrigerator if not used often, and discard portions to manage acidity. Do not use if mold appears or if there is an off smell or discoloration. Regular feeding helps prevent deterioration.