Koshu – a summary
- It is thought that Koshu’s origins in Japan can be traced back to 1186 when it was discovered growing wild at Katsunuma in Yamanashi prefecture.
- It is a hybrid grape, believed to have originated naturally by a crossing of the European Vitis vinifera and an Asian Vitis species.
- According to Wine Grapes (Robinson et al), Koshu’s DNA profile does not match any other known variety and its exact origin remains unknown.
- Koshu produces medium-sized bunches of large, thick-skinned, pink-tinged berries.
- The grape has been favoured for a long time in Japan’s humid climate because it is resistant to botrytis bunch rot. > Koshu is Japan’s most planted grape, and 95% of plantings are found in Yamanashi prefecture.
- Koshu produces delicate white wines that rarely exceed 12% ABV.
- The grape can also be used to produce richer versions when grown in low-yielding sites, or if cellar practices allow – with techniques including extended skin contact and/or lees contact, barrel fermentation and cryoextraction.
- The grape can also be used to make quality sparkling wine.
- Its range of styles, from the lightest to fullest, are particularly good complements to Japanese raw-fish cuisine, from subtle types to the salty, creamy sea urchin ‘uni’.
- In 2009, Koshu of Japan was founded to champion the grape, and in 2013, Koshu was recognised by the OIV.
