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.

We analyzed the physicochemical properties of commercially available top-fermented beer (ale) and bottom-fermented beer (lager) marketed in Korea to compare the quality characteristics. The following characteristics of beer were analyzed for their soluble solid content, pH, total acid content, alcohol content, volatile acid content, reducing sugar content, amino acidity, and color. As results, the pH ranged from 4.01 to 4.77, 0.10-0.23 (%) for total acid and 0.25-1.47 (mL/10 mL) for amino acidity. The alcohol content was in the range of 3.10-5.70 (%) for ale and 3.80-5.20 (%) for lager. The volatile acid content was in the range of 28.67-97.93 (mg/L) for ale and 32.80-78.87 (mg/L) for lager. Regarding the color, the EBC value of the ale beers was in the 4.78-93.98 range, and that of lager beers were in the 5.48-11.98 range. Comparison of the quality characteristics of the two types of beer, revealed differences in pH, amino acidity, total acid content, reducing sugar content, and color. In particular, total acid content (t=−3.782, p⟨0.05), reducing sugar content (t=−11.744, p⟨0.05), and color (t=−2.882, p⟨0.05) of ale beer showed significantly higher than those of lager beer.