Fermentation Control in Baker's Yeast Production: Mapping Patents

Abstract During baker's yeast manufacturing, the fermentation process must be thoroughly controlled. This review of the patent literature provides new information on the early development of industrial fermentation processes. As shown by a review of 199 patents filed between 1900 and 2009, inventors in this field were mainly interested to improve yeast yields through the control of infection and sugar concentration in the growth media. Contrary to common belief, much attention was also given to continuous culture processes, involving addition and withdrawal of growth media. These technologies were mainly developed in about 30 y, between 1910 and 1939. In the recent years, inventors gave sustained attention to the fine tuning of fermentation control, mainly the rapid determination of yeast fermentation by‐products in the exhaust to get rapid feedback on the rate of sugar addition in the fermentation tank. Improved fermentation control benefited much the baking industry because baker's yeast had higher gassing power and was cheaper. However, some of these key patents on baker's yeast technology were later declared invalid in court because it had little intellectual property value. In the baker's yeast trade and other sectors, this situation might have encouraged trade secrets while reducing the credibility of innovative ideas disclosed in the patent literature.