sourdough bread is a type of bread made through a natural fermentation process. It uses a mixture of flour and water to create a starter, which contains wild yeast and bacteria. This starter is what gives sourdough its unique tangy flavor and chewy texture. The fermentation process not only enhances the taste but also improves the bread's digestibility and nutritional value. Sourdough can be made with various types of flour, including whole wheat or rye, and is often characterized by its crusty exterior and soft, airy interior.