Kumamotoken Shuzo Kenkyujo was founded in 1909 as a collaborative effort among Kumamoto's sake brewers to elevate regional quality, led by Chief Engineer Dr. Kinichi Nojiro, whose mastery earned him the title 'a genius in sake making.' The brewery developed and continues to maintain Kumamoto Yeast, the original strain of Kyokai No. 9 Yeast, which is now used by breweries across Japan and is regarded as one of the most significant contributions to modern sake production. Koro sake is brewed using this proprietary yeast alongside underground water from Mount Aso and locally grown Kumamoto rice, producing sake with a gentle ginjo aroma and deep, rich finish.
