Quality characteristics of beer made using yeasts isolated from makgeolli or nuruk

The purpose of this study was to find brewing yeast suitable for beer from the native. This study was conducted to investigate the brewing properties of beer made using different yeasts isolated from makgeolli or nuruk. Five strains (Saccharomyces cerevisiae N9, N4, YM55, YM53, and YM22) were selected based on the ability to produce alcohol in maltose-containing media. These were then fermented in wort (11 °Brix) at different temperatures (15, 20, and 25°C) for approximately 7 days and then subjected to comparative analysis. The contents of alcohol and soluble solids were within 3.2-4.6 v/v% and 6.5-7.2 °Brix, respectively. S. cerevisiae YM22 produced more alcohol (4.0%) at 15°C while N4 produced more alcohol (4.6%) at 25°C. The pH was the lowest with N4 at 25°C (pH 3.74). Glycerol content was the highest with N9 at 25°C. Among organic acids, citric acid content was the highest in all treatments. In conclusion, yeast strains isolated from makgeolli or nuruk showed potential for beer making and optimal fermentation temperature varied depending on the yeast used.