(StarTribune) - As the Minnesota Grape Growers Association gathers in St. Paul this weekend, a new report shows how far northern winemakers have come.

The University of Minnesota-Extension report says cold-hardy grapes developed by the school and private breeders have generated a vibrant farm winery industry, pumping $401 million into the U.S. economy in 2011. And it says the industry has created 12,600 jobs in northern states.

The key was the release of four new varieties since the late 1990s —Frontenac, Frontenac Gris (gree), La Crescent and especially Marquette. They're all products of Minnesota's grape-breeding program and can survive winter temperatures well below minus-20.

Cold-hardy varieties make up 90 percent of the grapes grown in Minnesota, and are allowing other states like New York to expand their wine industries into new regions.