Junmai Kaya Brown (720 ml)

In 1946, Masumi's brewers isolated a yeast strain from their own fermentation tanks in Suwa, Nagano — that culture became Kyokai Yeast No. 7, now deployed by over 60% of Japan's sake breweries. Kaya Brown is built on that same proprietary yeast, brewed at the original Suwa Moto-machi kura where snowmelt from the Yatsugatake (Eight Peaks) Range via the Kirigamine Highlands has fed fermentation since 1662. The cold Suwa Basin climate slows fermentation, preserving aromatic precision while the mineral-rich alpine water drives a clean, structured finish.

The yamahai yeast-starter method is the technical signature: natural lactic-acid bacteria are cultivated in the shubo tank over approximately two weeks before yeast fermentation begins — no commercially added lactic acid. Where most breweries reserve yamahai for premium tiers, Masumi applies it across the entire range, including this entry. The result is a sake of measurably higher natural acidity and deeper lactic complexity than sokujo-method peers at the same grade. Rice is Miyama Nishiki, grown in Nagano, milled in-house at the brewery's own polishing plant to Junmai specification (≤70% remaining).

The special feature here is category-wide commitment: yamahai at volume is a deliberate rejection of the industry's efficiency norm, producing umami-driven structure that rewards food rather than standalone sipping — the founding philosophy unchanged since the Miyasaka family's samurai-era origins.