Junmai Daiginjo Sanka (720 ml)

In 1946, a single yeast strain isolated from Masumi's fermentation tanks in Suwa changed the entire industry: Kyokai Yeast No. 7 now drives fermentation in over 60% of Japan's sake breweries — yet Masumi alone brews every expression, including this Junmai Daiginjo, using the yamahai yeast-starter method, a labour-intensive two-week natural lactic cultivation that most producers reserve for prestige tiers or abandon entirely. The brewery sits at the junction of the ancient Koshu Kaido road and the Kirigamine Highlands approach in Suwa Basin — a site historically called Shimizu-machi, 'Clear Water Village' — drawing snowmelt water from the Yatsugatake (Eight Peaks) Range. That cold alpine hydrology and the basin's frigid winters create the slow, controlled fermentation environment that yamahai demands. Rice is milled in-house to Daiginjo grade (≤50% remaining), with Nagano-grown Miyama Nishiki as the primary variety, fermented in three-stage sandan-jikomi with data-logged temperature control. The yamahai starter builds natural lactic acidity without commercial acid addition, producing a structural backbone and umami depth that sokujo-method Daiginjo at this price point rarely achieves. Sanka drinks with a clean, food-oriented tension — the founding Miyasaka philosophy of sake so balanced 'you hardly notice it until the bottle's empty' expressed at Daiginjo polish.