To study the effect of nitrogen and phosphorus source addition on the agave juice fermentation by S. cerevisiae, S1 strain was used and fermentation medium was fed at D of 0.08 h−1, while the ammonium phosphate (AP) concentration was gradually increased, after the steady state was reached, as follows: 1 g/L (first addition), 2 g/L (sec- ond addition), 3 g/L (third addition) and 4 g/L (fourth addition).