Not surprisingly, much of the talk at this month's Cold Climate Grape Conference in Minneapolis was about … cold climates and grapes.

Especially how last winter's polar vortex (with 53 days below zero in Minnesota) affected grapes in these climes and the vines they grow on. Turns out it was quite a bit, but only temporarily and with lessons learned.

"We all suffered a lot, as did our grapevines," added Peter Hemstad, viticulturist at the University of Minnesota and co-owner/winemaker at St. Croix Vineyards in Stillwater. "When we harvested the crop," Hemstad said, "the output was pathetic."

Hemstad surveyed nine Minnesota wineries, all of which said injury to vines was very severe (44) or severe (56).

The bad news: Yields for the 2014 vintage were way down, by 50 percent or more, as vines lost many of their "primary buds" and produced a lot fewer clusters of grape. The good news: The vines by and large survived and should ease back into a groove this year, assuming our subzero nights don't extend well into March. The best news: Growers and vintners learned a lot about which grapes to grow and where.

"If you're going to have a sustainable industry," said John Maloney, owner of Cannon River Winery in Cannon Falls, "it has to be built around what we actually can grow here. I can't grow bananas in Sogn County [western Norway]."

Hemstad hammered home the way that, basically, growing good grapes is a lot like real estate: location, location, location. Last winter, he said, "is why we've been saying site selection is the No. 1 thing to worry about. We're a marginal place to grow grapes, so the sites are crucial." Places to avoid: low-lying areas (where the coldest air goes), damp and/or super-fertile soil (that whole "vines like to suffer" deal) and north-facing slopes (not enough sunshine).

Other takeaways from the conference, which 550 growers, winery owners and others attended:

• New wineries and vineyards are popping up throughout colder regions, many of them backed by some major money, said conference director Steve Unverzagt. "We're seeing new people coming into the business with deeper pockets, sometimes with an immediate million-dollar investment. We're not just mom-and-pop operations anymore."

• Northern vineyards still derive their revenues primarily from their tasting rooms, and should embrace that. "The trend is moving so much toward the experience and away from the product," said Lorri Hathaway, head of Michigan's Leelanau Peninsula Wine Trail, which includes 33 wineries.

• Wineries hereabout also should embrace wines that are on the sweeter side. Most grapes that do well in this area are high in sugar and acids and low in tannins. "Sweet sells," said Mark Wenzel, winemaker at August Hill in northern Illinois. "I don't know that the varietal matters so long as it's sweet." Bradley Beam, enologist for the Illinois Grape Growers and Vintners Association, noted that "the more rural your winery is, the more popular sweet wines are."

• Blending should be more prevalent. For starters, said Keith Bown, who oversees winemaking at six Constellation Brands wineries in Canada, "Consumers' acceptance of a varietal name is very hard to achieve." More important, as much is learned about the attributes and flaws of cold-climate grapes, vintners should look at ways that one grape might fill in the gaps of another. "We need to look at blending a lot more," Beam said, citing the Prairie Star' grapes ability to leaven the acidity of other white grapes.

• A newer red grape called Petite Pearl, developed by Minnesotan Tom Plocher, has a lot of potential. "It's got nice soft fruit, very nice tannins," said Irv Geary, owner/winemaker at Wild Mountain in Taylors Falls. He and others touted its blending compatibility with another promising red grape, Marquette.

• Marquette is a rising star. At the Winter Wine Fest tasting, most of the Marquettes I tried were very good to excellent, with the lesser ones perhaps owing to my aversion toward seriously oaky wines. Another grape developed by the University of Minnesota, the white La Crescent, also showed very well.

Overall, the nascent industry is making nice strides. "The chemical properties of grapes are better understood now," Unverzagt said. "We're really excited about the direction winemakers are taking now and the additional care and concern that grape growers are giving."

Follow Bill Ward on Twitter: @billward4.