Saccharomyces cerevisiae was grown in a chemostat under high glucose conditions (up to 300 g l(-1)). The results support the view that higher glucose feed favors higher ethanol production regardless of the existence of osmotic stress. A low glucose utilization and yield coefficient provides an opportunity to improve continuous fermentation performance in the fuel alcohol industry. The possibility exists of reusing yeast cells and subsequently lower operating costs, and by using an optimal glucose feeding concentration between 100 and 200 g l(-1).