Kouro is brewed by Kumamoto Prefecture Sake Research Institute, an organization founded in 1909 with the mission of elevating the quality of Kumamoto sake. The institute is the birthplace of Kumamoto Yeast, developed in 1952 and later registered as Brewing Society Yeast No. 9, which became one of the most widely used sake yeasts in Japan for its graceful aroma and gentle acidity. The flagship Daiginjo, made from Hyogo Yamada Nishiki polished to 38%, is considered a benchmark of the ginjo style and is sometimes called the phantom sake for its scarcity.
