(WRAL) - When Alexis Bailly Vineyard in Hastings and Northern Vineyards in Stillwater opened the first wineries in Minnesota in the mid-1970s, the concept was astounding.

Minnesota's harsh, unpredictable climate made it difficult to grow reliable wine-worthy grapes, and only a few followed the pioneering vineyards' lead, the St. Paul Pioneer Press reported.

Thanks to recent horticultural breakthroughs, however, wineries are popping up across the state, setting Minnesota on track to becoming a wine-making region. Today, the state is home to 60 wineries, compared with just six in 1999.

"It's been a learning curve. Once grapes were consistent and could survive from year to year, you started to see more vineyards," said Irv Geary, president of the Minnesota Grape Growers Association. "That's when the industry really started to take off. Today, we have a lot of high-quality wines."

Wine making in Minnesota is now a multimillion-dollar industry. The increasing number of wineries also has prompted local governments to grapple with licensing, zoning and other regulatory issues.

For decades, researchers worked on cold-hardy grapes that could withstand the Midwestern climate.

The late Elmer Swenson, considered one of the area's most famous grape-breeding pioneers, started intercrossing French hybrids with native grapes from his 120-acre Osceola, Wisconsin, farm as early as 1943, according to the Minnesota Farm Winery Association.

Swenson eventually joined forces with researchers at the University of Minnesota, and in 1978, they engineered two cold-hardy grapes, the Edelweiss and Swenson Red.

Swenson is credited with other grape varieties, including the St. Pepin, La Crosse and Prairie Star. The U also would introduce other grapes, including Frontenac varieties that are still widely used.

It was in the 2000s that more breakthroughs in commercial wine-making surfaced, Geary said.

The U started to focus not only on grape hardiness, but also on palate-friendly varieties for wine making. In 2002, the U rolled out the La Crescent white wine grape, which was soon followed by the widely used Marquette red wine grape.

"That really changed things. Grapes had been bred here before then, but they weren't really great wine grapes, and it was really hard to make good wine out of Minnesota," said Geary, noting that Minnesota wines now are winning awards in high-profile national competitions.

"They're not from California or New York. They're Minnesota wines. That's a testament to the quality of wines we're making today."

For wine makers, having more grape varieties that can survive a Midwestern climate has been a long time coming