Given that the literature on the biosynthesis of aroma from yeasts is scant, at best on the basis of our results, we could discern only few basic inferences. The data presented in Table 2 suggest that, with respect to the yeast strain D15, an alkaline pH is more favorable for the acetaldehyde biosynthesis as the culture medium had a TTA of 5.5 °SH. Such alkalinity is, however, not optimal for the synthesis of diacetyl, as the TTA of the medium fermented with D38 was 7 °SH, implying that a neutral pH favors diacetyl biosynthesis.