Junmai Ginjo Kuro Black (1.8 L)

In 1946, Masumi's brewers isolated a yeast strain from their own fermentation tanks in Suwa, Nagano — a strain now designated Kyokai Yeast No. 7 and deployed by over 60% of Japan's sake breweries. The Kuro Black Junmai Ginjo is brewed on that same house yeast,

at the original Suwa Moto-machi kura where snowmelt from the Yatsugatake (Eight Peaks) Range via the Kirigamine Highlands supplies very soft, mineral-clean water — a critical variable in the lactic fermentation that defines this brewery's character.

Masumi applies the yamahai yeast-starter method across its entire range: natural lactic-acid bacteria are cultivated in the shubo tank over approximately two weeks before yeast fermentation begins, generating a more complex lactic backbone, higher natural acidity, and a cleaner finish than the sokujo norm — without any commercially added lactic acid.

Rice is milled in-house to Ginjo grade (≤60% seimaibuai), primarily from Nagano-grown Miyama Nishiki, a variety selected for the cold-climate alpine terroir of the Suwa Basin. The 1.8 L format is the traditional isshobin — the working vessel of the Japanese table — and in this volume the yamahai's umami-driven structure and food-centric balance are fully expressed.

Drink now through medium term; the lactic complexity rewards gentle cellaring.