Linked from
The 27 pages that link to Sourdough, each with the reason it gives.
WheatRelated: Wheat flour is a common base for sourdough bread.
FlatbreadRelated: Sourdough fermentation can leaven flatbreads and add acidity.
Rye breadRelated: Rye sourdough acidifies dough and contributes leavening and flavor.
BliniRelated: Some blini recipes rely on sourdough cultures instead of commercial yeast.
EmmerRelated: Sourdough fermentation is one way to make bread from emmer flour.