That first vintage was produced with grapes grown on old-fashioned pergola trellises. The canopies of these vines can stretch 50 feet in all directions from a mother vine the size of a tree. Mr. Singer says that his new vineyards, which are planted with vines planted closely together in neat rows with new shoots trained up, a system common in Europe and America, are producing smaller grapes with more-concentrated flavors that will make even better wine.
In setting up the winemaking protocol for Mr. Singer’s koshu, Mr. Dubourdieu eliminated what was once the only thing that made koshu drinkable: sugar. The wine is bone dry with a very low alcohol content. He accomplished this by getting rid of the grape’s bitter skin early in the process.
“I tried to extract nothing from the skin,” he said. “The bitterness of the koshu skin is extreme.”
The wine is bottled in the spring to be sold fresh and young.
With such a simple wine, Mr. Dubourdieu said he was surprised that it pleased Mr. Parker, who is usually seen as a fan of full-bodied wines.
“I was afraid,” he said. “I was not sure he could like a wine with 10.5 percent alcohol. That’s not exactly the wine he ranks well. But he was enthusiastic.”
Still, Mr. Dubourdieu is skeptical that koshu will prove to be a valuable wine.
“It is simple, clean, fresh, nice,” he said. “That, and no more. It is a big mistake to think you can produce Montrachet in Japan. Koshu is more of a vinho verde.”
The Bordeaux producer Bernard Magrez is distributing a small amount of the Katsunuma Jyozo winery’s koshu in Europe and the United States. But the executive director of the winery, Youki Hirayama, said that beyond that, his company is focusing on Asian markets.
“This is Asian wine for Asian food,” he said, noting that the subtle flavors do not overwhelm delicate dishes.
Mr. Parker remains upbeat about koshu. “Up until this year, it was the best one I’ve tasted,” he wrote in an e-mail response to questions about Mr. Singer’s wine. “Now Bernard Magrez has one that is dry, crisp and very tasty, and much in the style of the Dubourdieu koshu. I think the wine, if made in these styles, has a quasi-Muscadet character — light-bodied and very refreshing.”
But there are wide variations in the new koshus, with some vintners experimenting with oak-barrel aging and each winery relying on a different level of chapitalization — adding sugar before fermentation — to increase alcohol levels along with adding weight and body to the wine. It is impossible, however, to be certain what Japanese wineries add to their wines. The country’s wine labeling regulations require that only 5 percent of the wine in a bottle be from Japanese grapes. The rest can be from anywhere.
Mr. Singer, Katsunuma Jyozo and the wineries of Koshu of Japan insist that their wines are 100 percent koshu.
But jaded Japanese wine drinkers have been slow to believe that they are worth their price tags of $20 and up.
After their first shipment to Europe this summer, the Japanese vintners involved in Koshu of Japan are hoping to gain international appreciation that would give koshu cachet in Asia.
On a recent trip to Japan, Michael Cimarusti, the chef and owner of Providence in Los Angeles, tasted a koshu produced by Katsunuma Jyozo and was so impressed that he added it to the wine pairings on his tasting menu.
But in New York, Mr. Singer’s importer, Robert Harmelin, said koshu had been a hard sell at $50 a bottle on restaurant wine lists. “No one knows the wine,” he said.
Mr. Singer asks for more time. “I’ve been in Japan for 50 years,” he said, “this movement is going to blossom.”