Cold Hardy Grapes: University of Minnesota Releases the Itasca Grape

                            Itasca grape

Chardonnay, Pinot Noir, Riesling and Gewürztraminer- what do they all have in common? They’re grapes that thrive in cooler climates and survive sometimes long and arduous winters. Now you can add Frontenac, Frontenac Gris, La Crescent, Marquette and Itasca to the list of cold weather favorites. These five grapes have been developed by the University of Minnesota Grape Breeding and Enology Project. This program specializes in research and grapevine cultivar development. According to their mission statement, they also focus on understanding the mechanisms of disease and pest resistance so that they incorporate these traits as a way to improve sustainability for Minnesota and other cold climate viticulture areas. Lastly they focus on developing and teaching enology best practices for cold-hardy grapes.


University of Minnesota, Grape Breeding and Enology Project

Matthew Clark, Ph,D., Project Leader of the University of Minnesota Grape Breeding and Enology Project said. “The University maintains about eleven acres of grapes, roughly 10,000 vines that are in all stages of ‘product development’. We evaluate new seedling vines in the nursery setting and in recent years have planted approximately 5,000 vines alone in the nursery. We are using DNA testing to screen plants for some traits, including disease resistance. After a year in the nursery, the vines that are top performers are moved to the vineyard where they are evaluated for cold hardiness, fruit quality, vine habit, disease and pest resistance, and eventually wine quality. It can take 3-5 years after planting before we can taste the fruit for the first time.  Dr. Clark continued, “We are using traditional plant genetic approaches to identify pest and disease resistance in the UMN breeding program. This involves making a cross pollination of two parents of interest, one that shows the trait such as phylloxera resistance and one that is susceptible. We grow out all of the seedling offspring from that pollination and then evaluate the progeny for the trait of interest. Preferably for multiple years, and in the field, greenhouse, or lab setting. We are then able to use genetic markers and statistics to help link regions of the genome with the trait. We have recently identified a new region of the grape genome that is associated with resistance to the foliar form of the insect pest phylloxera. Knowing where this resistance is, means that moving forward we can develop a DNA test to screen seedlings in the greenhouse rather than waiting 3-5 years for a field assessment to derive the same answer.”

In 2016 the Itasca grape was released and licensed nurseries began selling it in 2017.  The Itasca grape is one success out of 3-4,000 hybridization projects per year! It took fifteen years from the original cross pollination and testing to complete propagation and offering for sale in the marketplace.


Drew Horton, Enology Specialist, has been an active participant in the winemaking world for over 24 years. Starting his winemaking career in Santa Barbara CA, in 2010 he moved to Minnesota and began his current passion with cold-hardy hybrid grapes. Currently he focuses on outreach to the wine industry as well as making wine with new grapes that are created through the Enology project. In his work he makes wine from newly created grapes. He’ll analyze the taste, smell, mouth-feel of hundreds of test batches per year. He is one of the very first to make wine from the newly released Itasca grape.

Drew has made eighteen gallons of wine from the Itasca grape that he plans on sharing at the Minnesota Grape Growers Cold Climate Conference in March 2018.

But just what is the Itasca grape and how will the wine taste? “It has the flavor profile similar to a Pinot Grigio, Chenin Blanc, Sauvignon Blanc and some people say a Gewürztraminer,” Horton said. “It is an aromatic white wine with the aroma of pear as the predominant flavor. Also noted are hints of quince, violet and melon, lemon, apple and sweet herbs such as tarragon, basil and mint. It’s a complex white wine lower in acid than most other cold hardy grapes.”

It is a hardy grape that has been bred to be almost resistant to common diseases like powdery mildew and phylloxera. This should allow vineyard managers to reduce their spray inputs. Most importantly this grape is very tolerant to cold. In the 2013-14 Polar Vortex they only lost 4-5% of their primary buds due to freeze damage.

Winemaking tips

One area of focus is reducing the overall acidity of the juice. This is why they see such an improvement in Itasca over the other University of Minnesota varieties. It has about one-third the total acidity compared to its parents ‘Frontenac Gris’. Some winemakers have mentioned a frustration with is the higher acids of cold-hardy grapes of many varieties. Drew offers seven techniques to assist in making a balanced wine.

  • Let the grapes ripen as long as possible. This can be difficult in regions where the weather is an issue. You never know when a frost might happen or when a hail storm threatens to decimate a crop. “Higher sugar levels results in lower acidity. Let the grapevine work for you.” Drew instructed.
  • Use a strain of yeast that metabolizes and lowers malic acid content.
  • Malolactic (or secondary) fermentation this bacterial fermentation converts malic acid to lactic acid lowering total acidity and bringing a creamy component to the mouth-feel of the wine.
  • Add water. Yes, this is legal. Add water before the fermentation begins.
  • Cold Stabilization of wine. This process of cooling the wine that causes tartaric acid crystals to form. These crystals referred to as “wine diamonds” drop off in the bottom of wine containers. There is nothing wrong with these crystals, it is just that they are unsettling t some consumers to find crystals in the bottom of a glass.
  • Blend the wine with a lower acid wine. Federal regulations allow for up to 25% of another wine to be added to a wine and not have to be disclosed on the label.
  • Sweeten the wine with a little sugar. Food scientists have a term called “Bliss point” meaning that there is a point of perfect balance of feeling on your tongue. Balance the flavors and you balance the integrated whole.

“Like a sculptor uses many tools to create the perfect piece of art, I encourage all winemakers to do just the same. Don’t just use one of these techniques, use them all in moderation to achieve balance,” Drew said.

Indian Island Winery Winemaker Notes

“The Itasca wine is definitely one to be very excited about,” Winemaker Angie Netzke said. “The grape itself has lower acidity to start with than the other University of Minnesota varieties, which is a real advantage when it comes to making a drier white wine. I didn’t need to do any adjusting of the chemistry when it came in from the vineyard.” They picked at 24 brix with 3.31 pH and 11.4 g/L.

“Not knowing exactly what to expect from the wine, I used SVG to ferment with and used a simple nutrition plan throughout fermentation. I let it ferment dry, and will be back sweetening slightly before we bottle it. Flavors that stand out the most from this wine are citrus (lots of lemon) and grapefruit. There were also very subtle notes of honey.”

Notes from the Vineyard

Indian Island Winery in Janesville, Minnesota originated from the Winterhaven Vineyard and Nursery. The vineyard currently has over 6000 vines with seventeen different varieties and focuses on the newest cold hardy grapes. They’re one of three certified grape nurseries licensed to propagate Itasca. Plus they’re thrilled to be the first wineries to release an Itasca wine on the market.

Vineyard manager and co-owner Ray Winter currently has twelve acres planted with the Itasca grape and had this to say about how it behaves in the vineyard. “It grows very nice in the vineyard. It has real nice vigor with very little disease issues. The Itasca has nice upward growth habits. We planted it four years ago. We didn’t crop it until the fourth year but we could have cropped it in the third year. Production seems like it will be 5,000-8,000 pounds per acre. We have planted at 6 feet between plants and 8 feet between rows. It has been very hardy with little to no bud damage in the spring, almost every bud shots in the spring.”

“It is still too early to know how successful it is going to be. These vines may produce a small crop in 2018, but should be up to production in 2019-20 as the vines mature,” said Matthew Clark. “The University of Minnesota varieties are grown across the US and Canada in cold climate areas and have resulted in new industries in many states, allowing grapes to be grown and wine to be made in regions where before it wasn’t thought possible. Even in Minnesota, we have an economic impact of over $80 million. Our goal is to produce wine grapes with improved disease resistance that are cold hardy and make superb wines.”

For more information, if you wish to purchase any of the University of Minnesota’s grapevines go to:



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