Wild Yeasts

The wild yeasts in sourdough starters are not the same organisms as commercial yeasts. Consequently, they act somewhat differently. Also, different wild yeasts are found in different regions and environments. For example, the wild yeast that gives San Francisco sourdough its distinctive flavor is not the same as wild yeasts found in other parts of the world. If a starter is brought from one region to another, the sour may gradually change character because the yeasts in the new location apparently take over.