Japanese tend to be quick to warm to a new fad and just as fast to abandon it.

But the recent boom in drinking vinegar is showing signs of hanging around, as firms put out a wider variety of fruit-flavored vinegar drinks.

"I feel refreshed when I drink vinegar, especially in summer. I've had apple vinegar for drinking purposes, but now I want to try other fruit vinegars, like litchi and cranberry," said a 36-year-old housewife shopping for vinegar at the Takashimaya department store in Tokyo's Chuo Ward.

Vinegar brewer Uchibori Vinegar Inc. has seen average monthly sales at each of its six shops rise 10-fold from two years ago, when it opened its first Oaks Heart vinegar shop in Nagoya, said the managing director, Mitsuyasu Uchibori. The Yaozu, Gifu Prefecture-based firm opened its sixth fruit vinegar shop last week.

The shops offer more than 40 kinds of vinegar, made from mango, pears, raspberries, strawberries and other fruit. He said the vinegars should be drunk with water or milk.

"Wine and blueberry vinegars have been used as seasonings or cooking sauces by chefs. We wanted to spread these other vinegars (not just rice vinegar) to ordinary homes," said Uchibori, who calls himself a "vinegar sommelier."

Vinegar dates back to 5,000 B.C., when the ancient Babylonians are believed to have made it using dried grapes and dates. By the fifth century, rice vinegar had been brought to Japan from China and gradually spread to the public in the Edo Period (1603-1868).

Vinegar is mainly used as a seasoning, including the rice used in sushi and dressings for salads, but the number of people drinking it has grown.

According to Mizkan Group Co., Japan's largest vinegar maker, the market for drinking vinegar nearly tripled to 21.46 billion yen between March and August 2004 from 7.57 billion yen in the same period in 2000.

Sales of cooking vinegar stood at 12.98 billion yen in the same period, compared with 13.14 billion yen in 2000, the company said.

One reason for the upswing is that people have become more health-conscious and learned about vinegar's benefits.

Takashi Tajiri, a professor of food administration at Kinki University's agriculture department, said vinegar promotes blood circulation and also contains citric acid, which aids recovery from fatigue, stimulates appetite and assists in digestion.

"I think people believe that drinking vinegar is more efficient than taking it by eating dishes in which it is used as a seasoning," he said. "When foods are heated, some of the (nutritional benefits) of vinegar are lost."

So as not to miss out on the bandwagon, vinegar brewers have begun producing ever more varieties, including black vinegar, according to Ai Nakata, a Mizkan spokeswoman.

Mizkan, which has been producing apple vinegar for drinking since 1985, started making black vinegar beverages, a grapefruit vinegar product and a mixed-vinegar beverage using acerola and lemon in 2004, as well as a grape vinegar last February.

Uchibori said producing fruit vinegars for drinking was difficult.

"When we opened our first shop, our fruit vinegars were too sour to drink. So we made the taste mild and sweet by adding fruit juice taken from fruits used for making vinegar," he said, admitting it took several months to attract novice vinegar drinkers.

"I believe vinegar's sourness and strong aroma help relieve stress and make people feel relaxed," he said.