Saccharomyces cerevisiae is a promising organism for the production of organic acids.  It is well known and well accepted in the fermentation industry.  It is reasonably tolerant to low pH.  There is an exceptional tool box of genetic and genomic tools for manipulation of the yeast.  Tate & Lyle has over the last dozen years, with a number of collaborators, developed production of lactic acid in S. cerevisiae.  This work has been extended to the production of additional organic acids.  The model for collaboration, metabolic targets, and production cost drivers will be discussed.