Questions regarding baking and working with wild yeasts and starters (also known as levains or chefs).

Sourdough is generally used to refer to baked goods made using a culture of wild yeasts and symbiotic bacteria (usually Saccharomyces and Lactobacillus, respectively). This culture may be referred to as a starter, chef, levain, or mother. These cultures are usually maintained by adding a mixture of carbohydrates (such as flour, starchy vegetable matter, and/or sugar) and water to the existing culture and allowing it to rest in a warm environment while the microorganisms reproduce. A portion of this culture is then added when making a dough to leaven it.

For questions regarding other biological leavening agents see , and for questions regarding chemical leavening see or .