In Search of Perfect Growth Media for Baker's Yeast Production: Mapping Patents

Baker's yeast is a key ingredient for bread and, on the long term, changes in its manufacturing process had a major impact on the baking industry. As shown by a review of 236 patents filed between 1900 and 2009, the development of suitable growth media for baker's yeast was critical to improve its acceptability by the baking industry mainly through reduced cost and improved appearance (pale color). Based on the abandon of patenting activity on artisan yeast production in dough, acceptable commercial baker's yeast appeared on the North American market around 1920, but probably 5 to 15 y earlier in Europe partly because German inventors were the most active to develop growth media for baker's yeast. During the same period, grain-based media were replaced by diluted molasses that was cheaper. In the following 20 y, inventors put much energy on molasses clarification and miscellaneous sources of nitrogen to supplement it. Although molasses remains the basic raw material for baker's yeast manufacturing, alternatives are still sought for this application. In the early patent literature, cases were found where several inventors claimed intellectual property rights for the same invention described in patents filed in different countries and languages, which suggests that only thorough reading of patent specifications may distinguish inventorship from licenses and thus truly estimate patenting activity.