Roman bread

[Epictetus]

I suspect, and I would need to research this to be sure, that Roman bakers might have had a ready supply of yeasts in their equipment. I know that during the medieval and seventeenth century periods English bakers used wooden mixing troughs for their dough. These were not washed out and so built up colonies of wild yeasts. Does anybody know if there is a similar background in other European cultures or colonial America? Anybody know about Roman bakery equipment?

I did quite a bit of research about Roman bakeries for my novel, where one of the main characters is a baker. A lot of the bread the Romans made were unleavened, like Cato's libum. But when it comes to leavened bread they had many different varieties. Some bakers used sour dough continually, taking a bit away to make the loaves rise and feeding the 'root' or 'mother dough' to use the next day. They also had different leavening agents - in Gaul they used beer froth, according to Pliny. Other times they simply let each batch of dough rest for a long enough period of time for wild yeast to become established. Here was my experiment to make Pliny's grape juice bread in that manner.