Masumi has been brewed by Miyasaka Jozo in Suwa, Nagano, since 1662, when the Miyasaka family set aside their samurai swords to pursue sake making in the Japan Alps. The brewery's place in sake history was cemented in 1946, when brewmaster Chisato Kubota identified a distinctive yeast in one of its fermentation tanks; that strain, now known as Association Yeast No. 7, went on to be used in roughly 60 percent of all sake breweries in Japan. The brand name means transparency or truth, referencing an ancient bronze mirror treasured by the local Suwa shrine, and the brewery's guiding philosophy is to craft sake so well-balanced that it is noticed most when the bottle is empty.
