Two different control methods are applied to the technical scale (25 m3) fed-batch baker's yeast fermentation. Feedback linearizing control design is used to manipulate the substrate feeding rate in order to maximize the biomass yield and minimizing the production of ethanol. Firstly, the specific growth rate controller is developed and applied to maintain the specific growth rate at specified trajectory. Secondly, the minimal ethanol controller is developed to maximize biomass productivity, by controlling specific growth rate just above the maximum oxidative growth rate by controlling ethanol concentration. The both controllers worked successfully and can be combined to follow required specific growth rate trajectory and respond successfully to disturbances in overflow fermentations such as Saccharomyces cerevisiae.