NEW YORK » The restaurant looks like so many others in the roiling heart of Manhattan’s Chinatown: a garish sign in Chinese and English, slapdash photos of featured dishes taped to the windows, and extended Chinese families crowding around tables, digging into communal plates of steamed fish, fried tofu and sauteed watercress.

But ask a waitress the right question and she will disappear into the back, returning with shot glasses and something not on the menu: a suspiciously unmarked plastic container containing a reddish liquid.

It is homemade rice wine — "Chinatown’s best," the restaurant owner asserts. It is also illegal.

In the city’s Chinese enclaves, there is a booming black market for homemade rice wine, representing one of the more curious outbreaks of bootlegging in the city since Prohibition. The growth reflects a stark change in the longstanding pattern of immigration from China.

In recent years, as immigration from the coastal province of Fujian has surged, the Fujianese population has come to dominate the Chinatowns of Lower Manhattan and parts of Brooklyn and Queens.

These newcomers have brought with them a robust tradition of making — and hawking — homemade rice wine. In these Fujianese neighborhoods, right under the noses of the authorities, restaurateurs brew rice wine in their kitchens and sell it proudly to customers. Vendors openly sell it on street corners, and quart-size containers of it are stacked in plain view in grocery store refrigerators, alongside other Chinese delicacies like jellyfish and duck eggs.

The sale of homemade rice wine — which is typically between 10 and 18 percent alcohol, about the same as wine from grapes — violates a host of local, state and federal laws that govern the commercial production and sale of alcohol, but the authorities have apparently not cracked down on it.

A spokesman for the New York State Liquor Authority said the agency had recently received complaints about illegal Chinese rice wine and was looking into them, though he offered no further details.

New York police officials said the department had never investigated the trade.

The Fujianese wine sellers are reminiscent of an earlier group of immigrant entrepreneurs: During Prohibition, Jewish and Italian immigrants were among New York City’s most active bootleggers.

But several ethnologists and sociologists said that these days, there did not seem to be an equivalent illegal brew — made and sold in New York — among any other immigrant population.

The rice wine, which is almost always a shade of red, is the result of a fairly simple fermentation process involving glutinous rice, red yeast rice and water. Its taste varies from producer to producer and, of course, from drinker to drinker. The best versions recall sherry or Japanese sake. The worst, vinegar.

"Don’t underestimate this alcohol," cautioned a winemaker in Chinatown, who would give only his surname, Zhu. "You’ll get drunk."

In Fujian Province, people make rice wine in their houses, drinking it themselves, serving it to guests or using it in cooking. In New York City, many Fujianese immigrants do the same — a legal practice as long as the product does not enter the stream of commerce.

There are about 317,000 Chinese immigrants in New York City, according to census data, but that figure is widely regarded as an undercount. Zai Liang, a sociology professor at the University at Albany who has studied the tightly knit Fujianese population in New York, estimated that as many as 40 percent of the Chinese who immigrated to New York in the past two decades were from Fujian Province.

The underground trade in rice wine is foreign even to many Chinese from other provinces.

Since rice wine can go bad after excessive exposure to heat, it is widely regarded as a winter beverage, and vendors flourish in Fujianese neighborhoods during the colder months. But even in the depth of summer, a glass of it is never hard to find.

Indeed, many Fujianese are more than happy to talk about rice wine, explaining how it is made, describing its delights and extolling its virtues as an all-around elixir.

"If you drink this, you’ll stay young," explained Chen Dandan, a retired garment factory worker from Fujian Province. "It helps you with your circulation."

"If you drink this, you’ll live to an old age," said Lin Yong, a long-distance bus driver who lives in Queens. He said his grandfather, who died several years ago at the age of 99, lived by a simple dictum: It is all right to forgo a meal, but it is not all right to forgo a glass of rice wine.

Many said that even though legal rice wine is commercially available, they prefer homemade brews because they are said to have fewer additives.

But finding consumers is one thing. Tracking down moonshiners is another.

Over the past several weeks, interviews with dozens of Chinese store owners, restaurateurs and street vendors yielded prevarications, obfuscations and otherwise fraught conversations.

Nearly all said they were simply selling a product that others had made. Some spoke mysteriously of unnamed wholesalers who materialized once a week with supplies. Others seemed less concerned about the legality of the product and more concerned about the competition.

"What if you were to learn how to make it and set up shop across the street?" asked one restaurateur in Queens.

In some places, it appears, anyone can buy bootlegged rice wine, as long as you know what to ask for and hand over your money, usually between $3 and $5 a quart. But in other places, a non-Chinese person, even one who speaks fluent Chinese, might not get far.

When the manager was asked for rice wine at a store on Market Street in Manhattan’s Chinatown, fear swept over her face, and she said she did not have any. What about those unmarked containers sitting in a soft-drink refrigerator next to the Coca-Cola and Gatorade? "Not for sale!" she blurted.

At a store on Allen Street, a cashier first said she did not stock rice wine and went back to watching a video on a laptop. But when it was pointed out to her that several quarts of rice wine were stacked on the counter next to the cash register, she looked flustered and exclaimed: "It’s for cooking, for sauteeing!" Then: "It’s only for the Fujianese!"

A vendor below the overpass of the Manhattan Bridge on East Broadway said he did not know who had supplied him with the rice wine stacked on metal shelves on the sidewalk. But several containers were affixed with a small label for a Fujianese food supplier on Catherine Street.

At that address, a Fujianese man wearing an apron came to the unmarked door. Shown the label, he said it was the wrong address. Then he said that it was the right address, but that the business on the label had moved.

Finally, he admitted that the business on the label was his, but he insisted that he did not make rice wine. With that, he said he had to get back to work, and shut the door.