Effects of different yeasts on the quality of highland barley whiskey

Using highland barley and malt (1∶1) as raw materials, three different whiskey yeasts (M-1, USW-6 and D-53) were selected to brew highland barley whiskey. The fermentation performance, physicochemical indexes of fermentation liquor, and liquor yield per unit raw material of different yeasts were compared, sensory evaluation was conducted for the prepared highland barley whiskey samples before storage, and the volatile aroma compounds were qualitatively and quantitatively analyzed by GC-MS. The results showed that the optimal scarification condition was 65 ℃ for 70 min. The yeast M-1 exhibited the optimal fermentation performance, the alcohol content of fermentation liquid reached 7.29%vol after fermentation 72 h, and the liquor yield per unit of raw material was the highest, reaching up to 194.91 ml/kg. The types of flavor substances detected in the highland barley whiskey produced by 3 kinds of yeast from high to low were M-1 (19 kinds), USW-6 (17 kinds) and D-53 (13 kinds). The flavor compounds content in whiskey samples prepared by strain M-1 was higher than that of samples prepared by strain USW-6 and D-53, and the content of other ester compounds except 3-methylbutyl acetate and ethyl hexanoate was higher than that of samples prepared by strain USW-6 and D-53, which provided more fruit and floral aroma to the highland barley whiskey. The whiskey sample prepared by strain M-1 contained the least 3-methyl-1-butanol and was less prone to headaches after drinking. The sensory score of the whiskey prepared by 3 kinds of yeast in order was M-1 (81.8 points)>USW-6 (72.7 points)>D-53 (63.3 points). It was proved that yeast M-1 was more suitable for brewing highland barley whiskey.