Koshu (‘甲州’) is a white grape variety, with a name originating from the ancient name of Yamanashi prefecture in the central south of Honshu island. It is the most-produced wine grape in Japan, and 96% of Koshu wines are produced in the Yamanashi prefecture, where plantings are estimated at about 450ha. Production in 2018 reached almost 3,300 tonnes in Yamanashi, according to Japan’s national tax agency (though not all used for wine production), followed by 78t in Shimane and 27t in Yamagata.
The story of the origin of the Koshu grape has two versions. One is that in the early 8th century, a well-respected Buddhist monk Gyoki brought this grape to Yamanashi from Nara (the nation’s capital at that time) and planted the first Koshu vines. Another explanation is that in the late 12th century, local resident Amemiya Kageyu found some wild grapes on the way home and planted the seeds.
A recent DNA study revealed the truth of its origin; Koshu sits within the family of Vitis vinifera. Its European parent was first brought to China via the Silk Road and naturally crossed with
