Fermentation characteristics and industrial potential of <i>kuratsuki</i> sake yeasts isolated from Niigata Prefecture, Japan

The sake industry continues to evolve in response to consumer demand for novel flavor profiles and fermentation characteristics. However, the genetic and phenotypic diversities of kuratsuki sake yeasts (brewery-specific landraces), which are critical for regional uniqueness and flavor development, remain poorly understood because of limited research and the inherent difficulty of distinguishing these indigenous strains from industrial counterparts. Using molecular biology techniques developed in our laboratory, we successfully isolated indigenous yeast strains from sake breweries in Niigata Prefecture. Subsequent sake fermentation analysis demonstrated substantial phenotypic diversity among these isolates, revealing a wide range of fermentation performance and distinct flavor compound profiles. These findings confirm the continued presence of diverse kuratsuki sake yeasts with industrial potential and highlight their practical applicability in broadening the flavor profiles of sake products.