Fujino: ‘Koshu has long ageing potential’

Koshu, the indigenous white grape variety in Japan, which is generally known for its mild flavours and low alcohol, has the potential for long ageing, according to the winemaker at one of Japan’s largest producers Château Mercian.

Katsuhisa Fujino, senior winemaker at Château Mercian

Speaking to dbHK during a visit to Hong Kong, Château Mercian’s senior winemaker, Katsuhisa Fujino, said the pink-skinned table grape has high potential for ageing either with its sweet wine or the ‘new style’ of dry Koshu such as the winery’s Merician Koshu ‘Kiiroka’, a joint research project between the winery and the late Takatoshu Tominaga of Bordeaux University to develop Koshu wines with higher acidity and more complex flavours.

The indigenous grape variety, which is mostly planted in the Yamanashi region near Mount Fuji, was described by Jancis Robinson MW at a recent ProWine Asia masterclass as pure but Koshu wines, “really challenge you to get the flavours out of it,” she commented.

Addressing the general perception of Koshu, Fujino said: “As one comment people would say, the old style of semi dry Koshu is mild, neutral and lacks good acidity and doesn’t have the possibility to be aged for a long time.

“But the new style of dry Koshu,which has a clean and good aroma of citrus, good acidity and well balanced taste, has the possibility to age for a long time.”

The winery, considered one of the largest in Japan, started to develop Koshu wines in 1975, and since the 1990s the winery has begun to use the sur lie method for its dry Koshu wines to give extra body and flavours.

In 2003, the winery was able to identify a precursor of 3MH in the Koshu variety, which has resulted in the launch of its ‘Kiiroka’, a new style of Koshu with good acidity and citrus flavours, according to Fujino. Most of Château Mercian’s output, like other Japanese wineries, is consumed domestically. “We have a lot of possibility to export to various countries in the world and you will enjoy the paring some kind of elegant cuisines, especially seafood,” he elaborated. Starting from this month, the winery will begin to export its wines including Koshu to Hong Kong, he added.

The winemaker recently tasted back vintages of Kiiroka Koshu, from its release vintage of 2004 to the more recent 2012 vintage, and he said the wines held up well. “In fact, we enjoyed to taste Château Mercian Koshu ‘Kiiroka’ 2004 (first released in 2005), 2007 and 2012 in the wine cellar this May,” he stated.

The grape is believed to have been brought to Japan along the Silk Road through China more than 1,000 years ago. It is an oriental Vitis vinifera (a little mixed of Vitis Davidii from South Lake State in China) for white wine, Fujino explained. 

In addition to Koshu, the winery makes Chardonnay, Sauvignon Blanc, Pinot Gris, Syrah, Merlot, Cabernet Sauvignon as well as Japan’s own Muscat Bailey A.