The second strategy was to add S. cerevisiae ITV-01 and molasses “B” to the fermentation culture with S. stipitis NRRL Y-7124 (50% HBC enriched with molasses “B” 8% v/v) at 42 h when all the sugars present in the medium were completely consumed and ethanol concentration was near its critical ethanol tolerance. Results are presented in Fig. 4, where a significant increase in ethanol concentration after 50 h, 8 h after adding the molasses “B” and 1.4 gL−1 inoculum by S. cerevisiae ITV-01 can be observed. Maximum ethanol concentration was 53.80 gL−1 at 50 h. These results suggest that when S. stipitis NRRL Y-7124 is at its critical ethanol tolerance limit, it is completely inhibited, so it cannot interfere with S. cerevisiae ITV-01 fermentation activity.