Junmai Ginjo Shiro White (300 ml)

In 1946, Masumi's brewers isolated a yeast strain from their own fermentation tanks in Suwa, Nagano, and handed it to the Brewing Association — today, Kyokai Yeast No. 7 drives fermentation in over 60% of Japan's sake breweries. Shiro White is brewed at the source of that lineage. The Suwa Moto-machi kura sits at the junction of the ancient Koshu Kaido road and the Kirigamine Highlands approach, drawing water from the Yatsugatake (Eight Peaks) snowmelt — soft, iron-low alpine water that preserves delicate ginjo aromatics and keeps fermentation clean. Rice is polished in-house to Junmai Ginjo grade (≤60% seimaibuai), primarily from Miyama Nishiki, a Nagano-bred variety suited to the basin's cold climate. The defining technical commitment is yamahai yeast-starter: natural lactic-acid bacteria are cultivated in the shubo tank over approximately two weeks before yeast is introduced — no commercially added lactic acid — producing a sake with greater structural acidity and lactic depth than sokujo-method peers at the same grade. What is unusual here: Masumi applies yamahai across its entire range, not as a premium-tier distinction but as a house-wide standard, making Shiro White a rare entry point into full yamahai complexity. The 300 ml format delivers the same production philosophy as the flagship expressions, ready to drink now with no aging required.