Koshu is a Japanese white wine grape variety belonging to Vitis Vinifera species. The cool climate regions near Mount Fuji give the perfect condition for Koshu to grow.
Japanese have been using this variety of grape from very early times as table grapes. Recently, Koshu has made its own place among world’s best wine making grapes.
Yamanashi Prefecture, located in Main Island of Honshu Japan, is considered as the traditional home of koshu. Grace, Haramo, Lumiere and Marufuji are other major Koshu producers.
Unfortunately, Koshu made wines are not very popular among Japanese locals. They prefer western wines over Koshu. In the recent years, Koshu growers like Misawa have experimented with Koshu grape variety to make it more popular in Japan.
The grape variety Koshu or the plantation region Yamanashi is not registered with the EU authority officially until 2010. Koshu wines are low in sugar and acidic content, so to increase the alcohol amount in the wine, wineries in Japan add extra sugar and acid to the wines which is not permitted by EU authority.
The good news is that many winemakers from Tokyo like Mr. Singer; a wine exporter himself is using the local grape Koshu and expertise from France to make Koshu a potential wine grape variety. 480 hectares of cultivated land in Japan is dedicated to planting Koshu grapes.
History of Koshu grape
The history of Koshu in Japan is traced back to 1000 years ago, when this variety reached Japan through Asia Minor from west. Koshu was brought to Asia through Silk-Route. Previously Koshu was eaten by Japanese as table grapes. In the year 1874, koshu was used for the first time for making wine.
Wine making from Koshu not only commercialized the grape, but also made it popular in Japan. A DNA research on Koshu grape shows that it belongs to Vitis Vinifera family from Europe by 17th century the fruits Koshu became very popular and in the early 19th century Koshu was grown for export.80 wineries which are 95% of Koshu grape wineries in Japan are located in the Yamanashi, a wine producing region near Mount Fuji.
In the year 1997, total production of Koshu grapes in Japan was about 250,900 metric tons.
Viticulture and winemaking of Koshu grapes
Some of the important factors for planting koshu in Japanese Vineyards are; land should have gradient less than 4 degrees, prolonged solar radiation, annual rainfall of 1000 on average and prevention from soil erosion.
Koshu is prone to diseases and soil erosion conditions, so a proper care should be taken to protect the Koshu in the initial periods. The berries of Koshu grapes are pinkish in color. The uneven rainfall is yet another challenge to planters.
The wines made from Koshu grapes are naturally very acidic. some of the popular wines made from Koshu grapes are; Grace Winery Kayagatake 2008, Lumiere Koshu Sur Lie 2008, Alps Koshu 2008, Yamanashi Sol Lucet Koshu 2009, Sadoya Koshu 2009 and Diamond Winery Chanter Y, A Amarillo 2008.
Koshu is a late ripening between Octobers to November. In the recent years the western countries have started taking notice in Koshu wines.
Characteristics of Koshu grape wines
Since koshu grapes are less sweet and less acidic, it is chaptalized (adding extra sugar) before the fermentation process. The alcohol content in these wines is about 10% by volume, which is very less in compare to other standard wines.
Now more dry and sparkling wines are produced from the Koshu grapes. The color of these wines is pale. The aroma of Koshu wines are of citrus and peach.
Keeping Japanese cuisine in mind the wineries make more dry and subtle wines for the local market. The wines made from Koshu grape variety have lemon and fresh flavor.
But with time Koshu wines are blended with different varieties of wines that give flavor of mineral and herb along with lemon.
Food pairing with Koshu grape wines
The Japanese and European cuisine is preferred with koshu grape wines. Mochi, Tempura and beans are some of the Japanese cuisine to go with koshu wines.
In Japan, these wines are paired with pickles too. Pasta, salads, chocolates and fried rice can be other options that can go well with this variety of wines.
Editor-in-Chief and Wine Writer
Michael is an online enthusiast, with a lot of knowledge about online marketing. Traveling around the world to hunt for the perfect wine. Latest on Sicily, where Etna has a huge impact on the taste, which is strong with a bitter aftertaste for the youngest wines, but older wines are fantastic. Drinking wine, and writing about them, are one the passions. Remember to drink responsibly 🙂