Masumi Junmai Ginjo Shiro White (1.8 L)

In 1946, Masumi's brewers isolated a yeast strain from their Suwa fermentation tanks that would go on to define modern sake: Kyokai Yeast No. 7, now deployed by over 60% of Japan's breweries — yet Masumi remains one of the only large-volume producers to pair it exclusively with the labour-intensive yamahai yeast-starter method across every expression in the range. That two-week natural lactic-acid cultivation in the shubo tank, without any commercially added lactic acid, is what separates this brewery's profile from the sokujo mainstream.

The Suwa Moto-machi kura sits where the ancient Koshu Kaido road meets the Kirigamine Highlands approach, in a district historically called Shimizu-machi — 'Clear Water Village' — drawing snowmelt from the Yatsugatake (Eight Peaks) Range. That cold alpine water, combined with Suwa Basin's frigid winters, slows fermentation and sharpens the natural acidity the yamahai method already amplifies.

Shiro White is brewed at Junmai Ginjo grade (rice polished to ≤60% remaining), using Miyama Nishiki rice grown in Nagano — a variety bred specifically for the prefecture's high-altitude, short-season conditions. The yamahai starter delivers a lactic backbone that lifts the ginjo's characteristic fruit register without softening it into sweetness, producing a sake structured for food rather than standalone sipping. The 1.8 L magnum format is the brewery's traditional izakaya-table size, designed for extended, unhurried meals.

Expect white peach, rice koji, and a clean lactic edge; the drinking window is open now and suited to the next 12–18 months.