Yes, however not in the way we do today. Prior to the later half of the 19th century bread was made with what was called a sponge. In fact it was not until the late1850s through the work of Louis Pasteur that we even knew the mechanism by which yeast allowed bread to rise,. Throughout much of human history yeast has been created as a byproduct of fermentation, mainly the fermentation of beer, which dates back likely at least to ancient Mesopotamia. This is of course why many yeasts we purchase today are called Brewer’s Yeast as historically yeast was created through the craft of brewing. Beer brewing creates an excess of yeast, which when mixed with a small amount of flour, will create a frothy sponge- like mixture. This would then be kneaded with more flour and any other ingredients to create a standard bread, the staple food of European diets, and an important part of most other regions diets. Another method of rising bread was to use a small amount of a previously risen dough into a new batch to cause a rise. The earliest uses of yeast likely began with dough which was exposed to naturally occurring environmental yeast. This yeast could then be reused by adding bits of the dough to new batches. The first packaged yeast was available in the early 19th century, but did not enter common use until later that century. Both using a sponge created with the dregs of beer and one from previous doughs would have been common in 14th century Europe.

https://blogs.scientificamerican.com/artful-amoeba/yeast-making-food-great-for-5000-years-but-what-exactly-is-it/ https://www.amazon.com/Rise-Yeast-Fungus-Shaped-Civilization/dp/0190270713 https://www.target.com/p/the-bread-bible-the-bread-bible-by-rose-levy-beranbaum-hardcover/-/A-11498148?ref=tgt_adv_XS000000&AFID=google_pla_df&fndsrc=tgtao&CPNG=PLA_Entertainment%2BShopping&adgroup=SC_Entertainment&LID=700000001170770pgs&network=g&device=m&location=9004778&gclsrc=aw.ds&ds_rl=1246978&ds_rl=1248099&ds_rl=1246978&gclid=CjwKCAiA_f3uBRAmEiwAzPuaMw9AUgT8hrRbiBt9PoIbz7vX6uRdp1Qd-O-uDiGzuu7ASLLgXe_RiBoCWysQAvD_BwE