Abstract: On the basis of the kinetic model of beer fermentation process, ant colony system algorithm is applied to optimize the process. During a fixed period of fermentation time, a series of different temperature profiles of the mixture are constructed, and an optimal one is chosen at last. The optimal temperature profile maximizes the final ethanol production and minimizes the byproducts concentration and spoilage risk. Simulation results show that using ant colony system algorithm to optimize the process, we can get satisfactory results without much computation effort.