Junmai Ginjo Kuro Black (300 ml)

In 1946, Masumi's brewers isolated a yeast strain from their own fermentation tanks in Suwa, Nagano — a discovery that became Kyokai Yeast No. 7, now deployed by over 60% of Japan's sake breweries. That same proprietary yeast drives every bottle in the range, including this Junmai Ginjo.

The brewery sits at the junction of the ancient Koshu Kaido road and the Kirigamine Highlands approach, in a district long called Shimizu-machi — 'Clear Water Village' — where water drawn from the Yatsugatake (Eight Peaks) Range snowmelt delivers softness and mineral clarity to the fermentation.

Primary rice is Miyama Nishiki, a Nagano-bred cold-climate variety polished to Ginjo grade (≤60% remaining), milled in-house at the brewery's own polishing plant. Fermentation proceeds via the yamahai yeast-starter method: natural lactic-acid bacteria are

cultivated over approximately two weeks in the shubo tank before yeast is introduced — no commercially added lactic acid — yielding higher natural acidity and deeper lactic complexity than the modern sokujo norm.

What sets Masumi apart categorically is the house-wide application of yamahai across the entire range, not merely reserved for prestige tiers, making this 300 ml format a rare entry point into a genuinely labour-intensive tradition. The result is structured, umami-forward, and built for the table — the founding Miyasaka philosophy of sake so balanced it disappears with the meal.