The objective of this work was to evaluate the influence of the process variables involved during the alcoholic fermentation of the whey permeate. The tests comprehended lactose hydrolysis followed by glucose-galactose anaerobic fermentation in a batch system. A fractional factorial design with triplicate at the central point was prepared to carry out the alcoholic fermentation of whey, where the system response was considered to be etanol produced. Five variables were evaluated: pH, temperature, agitation, initial concentration of yeast and supplementation with yeast extract and peptone. Quantification of ethanol was determined in ultra performance liquid chromatography. The experiments showed that the ethanol produced depends on temperature and agitation velocity. The best conditions for ethanol production occurred at 50 rpm agitation, temperature of 32˚C, initial concentration of yeast in OD600nm of 0.8 and suplementation of medium 3 g L-1 of yeast extract and 1.5 g L-1 of peptone resulting in 45.3 g L-1 of ethanol.