Korean traditional rice wines yakju and takju are generally
brewed with nuruk as the source of the saccharogenic
enzymes by natural fermentation. To improve the quality of
Korean rice wine, the microorganisms in the nuruk need to
be studied. The objective of this research was to improve
the quality of Korean wine with the wild-type yeast strains
isolated from the fermentation starter, nuruk. Only strain
YA-6 showed high activity in 20% ethanol. Precipitation
of Y89-5-3 was similar to that of very flocculent yeast
(>80%) at 75.95%. Using 18S rRNA sequencing, all 10
strains were identified as Saccharomyces cerevisiae. Volatile
compounds present in yakju were analyzed by gas
chromatography-mass selective detector. The principal
component analysis (PCA) of the volatile compounds
grouped long-chain esters on the right side of the first
principal component, PC1; these compounds were found
in yakju that was made with strains YA-6, Y89-5-3, Y89-5-
2, Y90-9, and Y89-1-1. On the other side of PC1 were
short-chain esters; these compounds were found in wines
that were brewed with strains Y183-2, Y268-3, Y54-3,
Y98-4, and Y88-4. Overall, the results indicated that using
different wild-type yeast strains in the fermentation
process significantly affects the chemical characteristics of
the glutinous rice wine.