Influence of the fermentation pH on the final quality of Blanquilla pear spirits

摘要

Blanquilla pear concentrate was diluted, fermented and distilled to produce the pear spirits. The fermentations were held at the native pH and at an acidified pH of 3.2. Two sets of experiments were performed using a different fermentation yeast and a different distillation equipment. The heart fractions from each distillation (which form the pear spirits) were analysed by gas chromatography. The results showed, in both experimental sets, that reducing the fermentation pH significantly increased the concentration of most of the higher alcohols and decreased the concentration of ethyl acetate in the spirits. Moreover, pear distillates obtained in the first experimental set showed significantly higher concentrations of most of the long-chain ethyl esters (C_6-C_(12)) compared to those obtained in the second experimental set.