Sourdough starter for your pizza crust relies on a process of long fermentation using lactobacilli and naturally occurring yeasts as the leavening agent. Airborne yeasts and friendly bacteria versus cultivated dry yeast causes the crust to have a slightly sour flavor, and a pleasing taste.

Sourdough starter may have originated in Egypt around 1500 BCE, and served as the primary way to leaven bread into the European Middle Ages. During the California Gold Rush, sourdough was the principal bread made in California and remains an icon of San Francisco culture today.

Science, legend and personal experience all confirm the benefits of baking bread and its many related products (pizza, rolls, baguettes, etc.) using a sourdough starter. Check the Knowledge Base link above for more information on the science.