A joint research group of Associate Professor Misa Otoguro and Associate Professor Munekazu Kishimoto of the University of Yamanashi Wine Science Research Center and Marufuji Winery Co., Ltd., a wine brewing company in Yamanashi Prefecture, created a natural wine without using cultured yeast imported from France. He developed a new method of producing high-quality wine through fermentation.
According to the University of Yamanashi, the method, called the scale-up method, uses natural yeast that is attached to the grapes.Starting with small-scale spontaneous fermentation of pre-harvested grapes, the scale is gradually expanded to include 0.5-2% of the fermented liquid, which will eventually become the starter, to the grape juice.Wine made with this method can impart the complexity of flavor that can be said to be characteristic of naturally fermented wine, and is expected to be applied to organic wine aiming for high quality.
In recent years, new wineries have been established one after another in Hokkaido, Yamanashi Prefecture, and Nagano Prefecture.Until now, most wineries have used cultured yeast imported from France and other countries, but this has the disadvantage that the taste of wine is uniform.
Therefore, more and more wineries are adopting natural fermentation, but the problem is that incomplete fermentation can make the wine too sour and produce unpleasant aromas.In order to overcome this problem, the research group conducted continuous tests over a period of 5 years and confirmed that the scale-up method reduced unpleasant aromas and produced high-quality wine.
