Researchers bring wine grapes to cold climes

It was not until last June, on a visit to wineries in Vermont https://suruchimohan.com/2017/07/26/wandering-the-vineyards-in-vermont/ that I learned about cold-hardy grapes. That the Finger Lakes region of New York State was churning out great Riesling didn’t make me wonder about the cold. I hadn’t tasted the wine, although a friend kept singing its praise. But why would I go for a New York Riesling when German and Californian are easily available, and delectable to boot.

But then in Vermont I tasted La Crescent and Marquette and heard of Elmer and Louise Swenson, seyval and vidal blanc and leon millot. What a treasure trove of grapes and the personal experiences of those who cultivate and work with them.

Minnesota.

Ken and Gail Albert of Shelburne Vineyards http://www.shelburnevineyard.com/ mentioned the research conducted at the University of Minnesota, when I went to visit their winery. A whole new world opened up.

A couple of weeks ago, while researching Wisconsin wines (who’d have thought!), I decided to finally get in touch with a horticulturist at the University of Minnesota. Ken had said that they hybridized vitis riparia with French varietals to create cold-hardy grapes. His Marquette and La Crescent were fruits of that labor. I called Matthew Clark, assistant professor of grape breeding and enology (aren’t the titles cool?!), at UMinn in St. Paul, Minn.

An aside: For those Californians who complain when the sun is not blazing down, there was nothing spring-like in Minnesota in early and mid April: both times Matthew told me it was snowing and the forecast was for six to eight inches.

Hybridizing.

The program at the university started about 40 years ago, so now there is a level of maturity in the varietals, as I had experienced in Vermont. Choosing parent vines that complement each other is key. Vitis riparia, explained Matthew, contributes high acid, which is not good, and high sugar, which is good.

Why is high acid not good, since that gives structure to the wine?

It is higher than the ‘high acid’ winemakers talk about. For example, Frontenac, also a varietal developed at the university has a Total Acidity (TA) of 13.05grams/liter before fermentation and 11.09g/l, post fermentation. By comparison, an Alsace Riesling, known for its high acidity, targets 6g/l post fermentation.

Vitis riparia, then, offers too much of a good thing – an embarrassment of acid, which has to be tempered. Malolactic fermentation that converts the acid to sugar, definitely for red wines and for some whites, in one technique that cuts the acid. Then there are yeasts that work better for high acid. Then Matthew said something that surprised me: Adding water to wine to reduce the acid. So obvious yet, who’d have thought!

Amazing volume of work.

For those of us who swim around in our pond, to bring up a metaphor from last week’s post, seeing the volume of research is a jolt to the system. Really, they do all that!? It is amazing to realize, as I do every day, how much I don’t know. It is not merely the science of winemaking that is its own world; I do not know the many worlds that are out there.

For instance, making parental decisions – not just about crossing Marquette and Frontenac with each other or another grape, but within the vineyard. Any new varietal has to survive the winter, insects, and disease. If there is fruit on the new vines, the first assessment takes place in the field. “It is a gestalt of the whole plant and how it performs,” Matthew said.

Then, when a varietal has passed all the tests, it goes to the lab. These have to be cool places that one day I hope to visit. There is at the university a research winery at the Horticultural Research Center. Here, 75 to 125 varieties of wines, including the better known ones that I’ve already mentioned, are tested.

New kid on the block.

This honor goes to Itasca, which already released, will find its ways into many wineries in the next few years. Matthew calls it a good everyday wine – not a strong aroma profile – that will also be used as a blending grape. It seems to meet the standard of Midwestern hardiness – resistant to powdery, down mildew, foliar phylloxera, and of course, cold hardiness.

Phylloxera itself has its own fascinating trans-Atlantic journey. One day I will delve into that. More will be coming on Midwestern wine grapes and others that grow in the 48

contiguous states. Stay with me on this exciting journey. Ask your friends to subscribe to my blog. I have no plans to sell anything to advertisers.

Image: Itasca® grape. Photo credit: “University of Minnesota, David L. Hansen. Photo taken at the U of MN Horticultural Research Center, Chanhassen. Minnesota Agricultural Experiment Station project #21-016, “Breeding and Genetics of Fruit Crops for Cold Climates,” principal investigator: James J. Luby. Matthew Clark, grape breeder.