U's new grape can withstand cold winters — though maybe not Minnesota cold

The University of Minnesota has developed a new hardy grape that can withstand cold winters — though maybe not Minnesota cold.

The state's renowned agriculture researchers have spent 20 years breeding, cultivating and observing the new grape, called Clarion, that it is now ready to be sold to winemakers and commercial growers.

But getting the bright, white wine grape ready for prime time wouldn't have been possible without Ray Winter, a vineyard operator in rural Janesville.

He, along with growers in Vermont and Upstate New York, have carefully grown and nurtured the experimental grapevines.

"It does make very nice wine," said Winter, who has run Winterhaven Vineyard & Nursery for more than a decade on an old corn and bean farm.

"But," he added, "it's a Zone 5 wine."

That last part is important. He has worked the Sisyphean task of starting and restarting Clarion vines toppled by arctic air blasts for a decade.

When the U of M announced earlier this week that Clarion, a cold-hardy, white wine grape and first new variety since 2017's Itasca, was now for sale to vineyards from the Rockies eastward, officials noted the grape might be tested within the bold north.

But its growth would be happiest in Zone 5 on the U.S. Department of Agriculture's plant hardiness map. Zone 5 is a thin band stretching northeast from the Colorado Rockies through the Central Plains. It kisses Minnesota's southern border and cuts across southeastern Wisconsin before hopscotching to slices of Upstate New York and southern New England.

"We've been watching this plant for over 20 years because the wine quality has been so good," said Matthew Clark, a U of M horticulture professor. "It's going to be easier for growers in the right regions, a little bit south of here."

The grape was tested at Winterhaven outside Janesville and at a winery in Upstate New York and Vermont. And it'd be a shame not to release Clarion, the researchers said.

Since the 1970s, the university has been a recognized home for cold-weather grapes. Moreover, the U takes a cut for each sale of the patented breeds.

Just five years ago, the U of M's Grape Breeding and Enology program put forth what some termed the "Honeycrisp" of cold-hardy grapes in Itasca — named for the legendary northern Minnesota state park and lake from which the Mississippi River flows.

Since then, more than 100,000 vines of the Itasca grape have been sold to vineyards across the U.S. and Canada.

Itasca wowed with lower acidity scores than usual for cold-hardy grapes. But, most importantly, the grape also lived through the polar vortex of 2014.

"They've come up with fancy names for, 'it's a cold winter,'" said Winter. "Nothing new around here. But Itasca came through it."

Still, some growers lamented that Itasca choked off the fruit from sunlight and airflow.

Clarion, compared to Itasca, is a more obedient plant, staying on the trellis, says the U's grape experts.

But the skittishness of Clarion in the face of deep-polar systems — such as the one bearing down upon Minnesota right now — is why the name, unlike past varieties like "Itasca" and "La Crescent," doesn't invoke Minnesota geography.

"For the next wine grape, we might come back for Minnesota, when it's for [growing in] Minnesota," Clark said.

Clarion's flavor profile is closer to that of a European grape than the notoriously fruity midwestern wines.

"It grows nice," said Winter, of the new white-wine grape. "It's not one of these that is so vigorous that it covers all the fruit up."

"It's loud and clear," said Clark, noting the wine's parallels with its namesake, a long trumpet popular in the Renaissance.

It just might grumble at wind chills dipping close to 50-below-zero.