Interest revived in California in the late 1960s, when a few winemakers attempted to show that the state could make a quality product. But only in the last decade or so have other states begun to regain their grape groove.

Each region is trying to find its own wine identity. While European classics such as cabernet sauvignon and merlot thrive in California’s long, warm growing season and have shown promise in Texas and Virginia, they don’t do as well in places prone to meteorologic extremes. In the humid South, for instance, many vintners have adopted the indigenous muscadine grape, which produces distinctive, perfumed wine in sweet or off-dry styles. In Minnesota, Frontenac, a cold-hardy red cultivar developed by the University of Minnesota, is flourishing. Today, Michigan makes some of the finest riesling in the country, while Virginia has made a name for itself with outstanding viogniers, notes Adam Dial, co-founder of Appellation America, a San Francisco-based wine website.

“We’re still figuring out what to do,” says Cameron Stark, a winemaker for Unionville Vineyards, which grows European varieties as well as native grapes in Ringoes, New Jersey.

To recognize the country’s varied winemaking regions, American Viticultural Areas, modeled on the French and Italian system, were created in the 1980s by the U.S. Alcohol and Tobacco Tax and Trade Bureau. Today there are 188 A.V.A.’s stretching from Altus, Alabama, to Walla Walla, Washington.

Newcomers stress that their wines should be judged in the context of their various regions. “We’re never going to out-California California,” says Jennifer McCloud, proprietor of 10-year-old Chrysalis Vineyards, in Middleburg, Virginia. She also acknowledges that Virginia will never match the quality of the first-growth Bordeaux she collects on the side.

She does, however, make a lush viognier, blockbuster reds from the native Norton grape, and some fine examples of lesser-known wines such as petit manseng, fer servadou, and albariño. “I want to grow world-class wines that can stand on their own,” she says. “I’d rather make the world’s best Norton than the world’s 400th-best merlot.”

That sort of ambition seems to be catching on among the country’s newest vintners. Where they were once content to make something merely quaffable, many are beginning to draw on the latest viticultural science and the expertise of trained winemakers.

Ste. Chappelle, founded in 1976 in Caldwell, Idaho, now makes 160,000 cases of wine a year. In 2000, it lured winemaker Chuck Devlin from California, where he had a small winery and acted as a consultant. “I’m sure they thought I was nuts,” he said of his West Coast colleagues.

Devlin has just finished his seventh harvest at Ste. Chappelle—now owned by giant Constellation Brands—where he makes luscious riesling, gewürztraminer, and ice wine high above the Snake River. “When I go back West, I bring wine, and they just about fall out of their chairs when they taste it,” Devlin says.

Similarly, when Cameron Stark left an enviable career in California—where he had worked with renowned winemakers such as Robert Sinskey, of Robert Sinskey Vineyards, and Bob Levy, of Harlan Estates—he took a lot of ribbing. “I still do,” he says. “Maybe that’s a private motivation for me, to be the first [in New Jersey] to break 95 in Wine Spectator.”

That’s a lofty goal, given that the big critics and publications typically ignore these winemakers, at least according to them. And when they are reviewed, their scores don’t exactly start a stampede (just as well, given their volume). They’ve had better luck at competitions such as the Tasters Guild International. In 2007, wineries from states including Michigan, Colorado, and Missouri took home dozens of medals.

“I don’t care if nobody knows about us,” says Ed O’Keefe, owner of Chateau Grand Traverse, known for its excellent rieslings, on Michigan’s scenic Old Mission Peninsula. “We’re seeing 20 percent growth annually.”