Question

Some bakers of sourdough and a few other types of bread have what they call “starter dough.” This dough contains yeast from which they make all their bread. Some starter dough is more than 100 years old. The dough has to be “fed” more flour and water on a regular basis for it to remain usable. Why must the starter dough be “fed”?

Answer 1

Starter dough, often referred to as a sourdough starter, contains a mixture of wild yeasts and beneficial bacteria that ferment the sugars in the flour, producing carbon dioxide and organic acids, which contribute to the bread's flavor and texture. The reason it must be "fed" with more flour and water regularly is to:

1. Provide Nutrients: The yeast and bacteria consume the carbohydrates in the flour as food. Over time, they deplete the nutrients available in the starter. Feeding it fresh flour adds new sugars and nutrients, allowing the microorganisms to thrive and multiply.

2. Maintain Activity: Regular feeding keeps the yeast and bacteria active. If the starter is not fed, the yeast can become dormant or die off, reducing its leavening ability and potentially impacting the flavor profile of the bread.

3. Control Acidity: The fermentation process produces acids, which contribute to the sour flavor of sourdough bread. By feeding the starter, you can manage the acidity levels and avoid an overly sour or unbalanced flavor.

4. Prevent Spoilage: A neglected starter can become unbalanced or develop undesirable microorganisms (like harmful bacteria or mold) due to the breakdown of nutrients, leading to spoilage. Regular feeding helps sustain a healthy fermentation environment.

Through these feedings, bakers maintain a vibrant community of wild yeast and bacteria, ensuring that their bread rises properly and has the desired flavor and characteristics.