(TwinCities) - Not so long ago, Minnesota had no wine-making industry. It sure does now, with 40 wineries in the state -- double the number from 2007 -- along with scores of picturesque vineyards, and more opening each year. The rapid growth of Minnesota's wine-making was clear this week at the Cold Climate Conference in St. Paul. About 400 people who grow grapes and make wine -- or dream of doing so -- came to learn, rub elbows and do some sampling.