Any premodern bread that wasn’t made like sourdough was made with beer barm. Bakeries and breweries were typical colocated. I’m not sure what was done in predom

Any premodern bread that wasn’t made like sourdough was made with beer barm. Bakeries and breweries were typical colocated. I’m not sure what was done in predominantly Muslim areas for yeast though, since they wouldn’t have had breweries.