Yeasts selected in the previous stage were used to formulate mixtures for fermenting agave juice. A simplex centroid design was used for mixture formulation. Fermentations were carried out in duplicate in 50-mL tubes containing 45 mL of agave juice, with the initial sugar concentration and C/N ratio being adjusted to 120 g/L and 73, respectively. Incubations were conducted at 28 C for 72 h, with sampling every 12 h. Biomass concentration was determined by direct counting in a Neubauer chamber. Samples were filtered through a 0.45-mm nylonfilter and stored at 80 C until analysis.