Isolation of a High Malic Acid-Producing Yeast Strain from Sake-Mash Obtained from Sake Breweriesand Low Alcohol Sake Brewing Tests Using This Strain.

Abstract

From a total of 314 yeast strains that have beenisolated from sake-mash made at sake breweries in Fukuoka Prefecture, 24-2 was isolated as the mostmalic acid-producing yeast strains and produced 1.7 times more malic acid than K-9, using a fermentationtest in YM-10 broth and koji-extract. K-9 and 24-2 were tested for CO₂ evolution, alcoholproductivity, acidity, amino acidity, organic acidproductivityinvolving malic acid, and flavor-productivityusing a small scale sake fermentation test. Strain 24-2 produced 2.2 times more malic acidthan K-9 and is suitable for sake brewing. Moreover, 24-2 also produced 2.5 times malic acid than K-9 using a small scale low alcohol sake fermentationtest. Low alcohol sake brewed with 24-2 results in agood taste balanced between sweetness and acidity.