The Koshu Grape and Vineyards

The Koshu grape is the only indigenous vitis vinifera grape in Japan and has been documented since the 8th Century. The fruit has thick pink skins with a bitter component and does not produce high sugar levels like other traditional European varietals. The grapes are typically grown in the Yamanashi and Nagano prefectures west of Tokyo and were considered a delicacy to the historical leaders in Japan. Koshu grapes were originally grown as table grapes which emphasized appearance, high sugar concentration and mass production. In order for this to be achieved, table grapes are grown in canopies (pergola) where each vine yields over 200 grapes. Contrastingly, wine grapes are grown for low yields to maximize concentration of flavor and appearance is less significant.

Top viticulture expert, Glen Creasy from Lincoln University in New Zealand, was brought to Japan to help us establish Koshu grape vineyards. With his experience in New Zealand’s climates and terrains, he was able to introduce new viticultural techniques to efficiently produce quality wines in Japan.

Technology and research discovered the most efficient methods to growing grapes for wine. The result is VSP (vertical shoot positioning) where grapes are grown in trellises to allow for maximum sun exposure to promote grape ripening and prevent disease. All European and internationally recognized wine grapes are grown in this fashion. Since Koshu grapes were originally grown for making food, at first we struggled to find high quality fruit to produce our wine. Over the years, we worked closely with farmers to plant new vines and improve their current vineyards to produce grapes suitable for making a world-class wine.

We currently produce and manage Koshu grapes at ten different vineyards located around Japan and continue to research the best conditions for the Koshu grape.