Abstract:  In the 19th century, bread had a pronounced acidic taste and a nonuniform appearance, as shown by a review of 178 early patents families on baker's yeast manufacture. This was largely due to the unpredictable nature of baker's yeast, which was generally grown under empiric conditions in nonsterile dough or liquid prepared with saccharified cereals. Inventors were mainly interested in techniques to increase yields of pressed yeast through media formulation, infection control, and automation of biomass separation and packaging. Still in its infancy, baker's yeast technology was slow to develop and apply new ideas due to lack of awareness on information published in patents and the scientific literature. This review also gives background information on early patents.