Open Access

Elif Ezgi Zabun

• For several millennia, yeasts are involved in the production of alcoholic beverages via the fermentation process. Yeast metabolism is responsible for the aromatic compounds produced during fermentation. Different yeasts create different aromatic compounds, or different concentrations of compounds during fermentation because of the metabolic differences between yeasts. In this bachelor thesis, the effect of utilizing native yeasts on the sensory properties of the produced alcoholic beverage is evaluated. A total of 83 isolates were obtained from the surface, juice, and 7-days-rested juice of fresh pears of Conference variety. Among these isolates, 19 of them were identified as yeast samples. For native yeast sample used in sensory analysis, among known species in the sample, Saccharomyces cerevisiae has the highest relative abundance, followed by Saccharomyces eubayanus. The odor scores were significantly higher for native yeast sample points than the odor scores of LT8 points. The difference between the total sensory analysis scores was not significant. The results showed that the native yeast performed as good as the commercial yeast in terms of sensory properties, with a significantly better odor perception and higher production of ethanol.