Yamanashi

The National Tax Agency's specification says Yamanashi wine production is said to have begun around 1870, when surplus table grapes were made into wine, and that the national government, the prefecture and municipalities have supported the industry since the Meiji period. The prefecture names Hironori Yamada and Norihisa Takuma, who began winemaking in earnest in 1874, and the first private winery, at Katsunuma in 1877.

A fermentation research institute, now the Institute of Enology and Viticulture, was set up at the University of Yamanashi in 1947; the prefecture also runs a wine centre at its Industrial Technology Center and a grape department at its Fruit Tree Experiment Station. Koshu (2010) and Muscat Bailey A (2013) were registered with the OIV. The GI was designated on 16 July 2013, and the prefecture named itself Japan's 'Wine Prefecture' in August 2019.

The specification describes a mountainous prefecture enclosed by the Akaishi Mountains along its western border and the Mount Fuji range from its southern border to the north-east. Little influenced by the sea, it is less affected by the rainy season and typhoons, which limits humidity in the growing season and wind damage at ripening. The basin climate brings warm days and sharp drops in temperature in the mornings and evenings. Vineyards lie mainly in the basins of the Fuji River's tributaries, many on gentle slopes of granite and andesite colluvium with deep, fertile, well-drained soil.

The National Tax Agency's sake specification for Yamanashi adds that the Kofu basin averages about 300 m and that high mountains block moist sea winds, giving little rain and long sunshine. The prefecture places most vineyards in the Kofu basin, with new plantings in its north-west and at the foot of the Yatsugatake Mountains.

The specification attributes Yamanashi's well-balanced wines, which keep each variety's own aroma and taste, to the long-established Koshu and Muscat Bailey A and to vinifera varieties chosen and grown to suit the local environment. Koshu wines have a rich aroma and a gentle taste, and dry ones show citrus notes and crisp acidity. Muscat Bailey A gives a rich red-purple colour, a fragrance suggesting sweetness and mild tannin. Vinifera whites have mild acidity and a ripe-fruit aroma; vinifera reds have depth of colour and balance between tannin and roundness. The specification also notes that Yamanashi wines contain less total iron than wines made abroad, which it links to the local taste for seafood.

The GI requires grapes harvested only in Yamanashi, from listed varieties: Koshu, Muscat Bailey A, Black Queen, Bailey Alicante A, Delaware, six hybrids such as Kai Noir and Sun-Semillon, and 31 vinifera varieties from Chardonnay and Merlot to Petit Manseng. Must sugar must reach at least 14% for Koshu, 18% for vinifera and 16% for others, 1% less in a bad year. No water, alcohol or spirits may be added, except brandy in limited sparkling-wine cases, and the wine must be Japan wine made, stored and bottled in the prefecture.

The finished wine must have 8.5% to under 20% alcohol (from 4.5% for sweet wines with at least 45 g/L of sugar), at most 250 mg/L total sulphur dioxide (except sweet wines), volatile acidity of at most 1.2 g/L for reds and 1.08 g/L for whites and rosés, and at least 3.5 g/L total acidity. The control body is the GI Yamanashi management commission at the Yamanashi Prefecture Wine Manufacturers' Association in Kofu.