May 2013 Issue of Wines & Vines

Northern Grapes Project Sees Results

Grant enables scientists to work together on projects benefiting cold-climate regions

by Linda Jones McKee
With the growth of the cold-climate grape and wine industry since the 1990s, it became apparent that the new cold-hardy varieties had unique characteristics that called for different growing, production and winemaking practices, and that the wines made from them would require marketing and promotion to increase sales. A planning grant from the Specialty Crops Research Initiative allowed a group of regional grower organizations and university researchers to hold workshops in Vermont and Minnesota to learn about the cold-climate industry’s needs and how they could be addressed.

With support from 19 producer groups from Nebraska to New Hampshire, and under the leadership of Tim Martinson of Cornell University, a group of 12 universities applied for a five-year Coordinated Agriculture Project (CAP) grant. In 2011 the grant was awarded to the project (called Northern Grapes: Integrating viticulture, winemaking and marketing of new cold-hardy cultivars supporting new and growing rural wineries) to cover three broad areas: crop production, processing (winemaking) and consumers/markets.

The goal of the project is to support and enhance the growth and development of wineries and vineyards in the northern regions of the Midwest and New England. The project is working toward the following outcomes:

• Double the production and sales of wines made from cold-climate cultivars.

• Improve quality through better growing and winemaking practices, which will improve customer retention and drive repeat sales.

• Establish unique regional marketing identities for areas that grow cold-climate cultivars.

• Apply business and tasting room management practices that drive sales.

• Transition from “startup” status to “sustained profitability.”

A major component of the project is education, both to communicate what is learned and to get feedback from producers about how the information has influenced their practices in the vineyard and the cellar. To reach parties in all 12 states that are involved, the Northern Grapes Project publishes a quarterly electronic newsletter and conducts webinars to provide an in-depth look at specific topics in grapegrowing, winemaking and marketing of cold-climate wines over the Internet. The project holds enterprise workshops and field days in each of the participating states to provide hands-on demonstrations and presents an annual Northern Grape Symposium to provide yearly summaries of the project’s progress. The first symposium was held at the Cold Climate Conference in Minnesota in 2012; the second took place in February during the Viticulture 2013 conference in Rochester, N.Y.

Although designed as a five-year program, the Northern Grapes Project was funded with a $2.5 million grant through September 2013. The project team plans to submit a renewal for the remaining three years of the project, which is dependent on Congress’ passage of a new U.S. Farm Bill.

What’s a ‘northern grape?’
Thirty years ago there were two wineries in Minnesota and eight in Wisconsin, primarily because winter temperatures in the northern Midwest were too cold to grow Vitis vinifera varieties. However, some of the French and American hybrids would survive, especially if the vines were dropped off the trellis wire, laid on the ground and covered with straw or dirt to insulate them from the cold. Then, in the spring, the process had to be reversed—the vines uncovered and tied back onto the trellis.

For most growers, this process was a huge amount of work. For a few, it became a challenge: Could grapes be bred to survive the cold, harsh winters and also produce wines that tasted good? Native grapes such as Vitis riparia had the cold tolerance but definitely not the appropriate wine aromas and flavors. The first riparia wine I ever tasted was a well-made wine, but it had the aroma of a freshly mown hayfield followed by grassy, herbaceous flavors. The grapes might get ripe enough, with sugar levels of 25° Brix, but the acids often reached as high as 2.4 grams per liter. As one winemaker put it, “Riparia grapes have a flavor level that will burn a hole in your mouth.”

The search for grapes that would survive cold temperatures and also make a palatable wine goes back to the late 19th century. One of the early breeders was Louis Suelter, whose variety Beta was a cross of riparia and Concord. The grapes were good for jam and tolerated cold winters but made inferior wine. However, Beta was used by Maxwell Dorsey as the hardy parent for some of the first crosses at the University of Minnesota around the time of World War I.

One of Dorsey’s crosses, known as Minnesota 78, became an important element in the breeding project of Elmer Swenson, who in some ways was the “father” of the northern grape varieties. Swenson was a farmer in Wisconsin whose passion was breeding grapevines for cold climates. He made his first cross in 1943, and after World War II he acquired about 20 different French hybrids to use in his grape-breeding crosses along with Minnesota 78.

In 1969, Swenson retired from farming and went to work for the Horticulture Department at the University of Minnesota as a gardener. For the first time, Swenson had access to greenhouse facilities and received exposure for his projects. In 1975 his grape E.S. No. 439 was named Swenson Red by a committee within the university’s Horticulture Department. Two more of his grapes were named in 1980: Kay Gray and St. Croix. Kay Gray is a second-generation grape whose parentage includes Minnesota 78, Golden Muscat and Onaka, a hybrid with Beta parentage that was developed in South Dakota. St. Croix is a fourth-generation cross by Swenson that includes Minnesota 78, Seibel 1000, Seyval and Seneca among its parents.

David Bailly, a Minneapolis attorney who started Minnesota’s second winery in 1977, recognized the significance of Swenson’s work, and according to an interview from the 1980s Swenson was the first breeder to make crosses using riparia that did not contain labrusca as one of the parents. Under the leadership of grape breeder Peter Hemstad, the University of Minnesota has continued the program initiated by Swenson. Four additional varieties have been released since 1978 including Frontenac, Frontenac Gris, La Crescent and Marquette.

Grapevine nurseries gradually increased the availability of the new cold-hardy varieties, and the number of small vineyards and wineries in the northern states in the Midwest and New England began to expand. In the 12 states that are part of the Northern Grapes Project the number of wineries has increased to more than 300, and 1,300 growers farm 3,300 acres planted with grapes.

Studies of viticulture practices have been initiated across six states. In Connecticut, Iowa, Michigan, New York and Wisconsin, spring frosts affected both yields and fruit quality. With above-normal temperatures during the growing season, berry quality indices were similar between training systems, canopy-management practices and cropping levels. Mid-season removal of axillary (lateral) shoots in the fruiting zone had the greatest influence on improving the light distribution in the canopies of Frontenac and La Crescent grapevines trained on a high-wire cordon system.

In cultivar trials of Frontenac, Frontenac Gris, La Crescent, Marquette and St. Croix, yield varied across eight trial blocks from Vermont and Massachusetts to North and South Dakota. Early bud break and subsequent frost injury reduced production but also accelerated development, and harvests were as much as one month earlier than average. Fruit composition at harvest was the best we could hope for from these cultivars, as they had ample time to ripen and came in with lower acidity than what is typical. At sites without frost injury, Frontenac vines were able to ripen up to 27 pounds of fruit per vine with no reduction in sugars or increased acidity.

A project to investigate the nutrient levels in soil and plant tissue has been started at 16 sites in five states. The first year of sampling found a wide range of soil types and nutrient levels. Tissue samples collected at three times during the growing season also showed that a wide range in nutrient concentrations will allow the determination of relationships between tissue nutrient concentrations, soil characteristics and grape quality for cold-climate varieties.

One of the challenges in growing grapes in the northern Midwest and the Northeast is the large amount of disease pressure and the need to protect vines from diseases starting at bud break and continuing through harvest. One of the objectives of the project is to evaluate the response of several cold-climate cultivars to copper and sulfur fungicides. Preliminary studies of copper and sulfur phytotoxicity in Wisconsin and New York showed variable results. In Wisconsin, Brianna was sensitive to copper, while Maréchal Foch and Léon Millot were sensitive to sulfur. In New York, all cultivars that were tested showed sensitivity to sulfur but not copper. As crop injury is highly dependent on environment, these studies must be repeated for years and at various locations before conclusions can be made.
—Tim Martinson

The cold-climate grape and wine industry accounts for more than $342 million in economic impact across 12 states, according to the year one baseline study conducted by the Northern Grapes Project. That economic impact includes growing grapes, making wine from cold-tolerant varieties and spending by tourists at the wineries. The cold-climate grape industry has experienced rapid growth, with 43% of wineries specializing in the production of cold-climate wines established after 2007 and 45% of the northern grape cultivar acreage planted within the past four years.

During a five-month study of more than 1,500 tasting room visitors, 49% indicated that visiting wineries was either the “only reason” or a “very important reason” for visiting the regions sampled. The research also showed that the primary reasons people visit wineries are to have relaxing and unique experiences. Such experiences are apparently highly valued by wine tourists, as average tasting room visitors spend a total of $780 during their trips to wine tourism destinations, further demonstrating the importance of wineries to those regions.

Research in customer satisfaction showed that converting tasting room customers from “satisfied” to “extremely satisfied” through excellent customer service sells more wine. A highly satisfied customer buys four bottles and spends $60 during a visit, research shows, whereas a satisfied customer buys three bottles and spends $40. Tasting room managers, therefore, should focus on friendliness and sharing knowledge to enhance customer experiences.
—Tim Martinson

In 1996 the University of Minnesota released the wine grape cultivar Frontenac, a cross between Landot Noir (an early hybrid developed in France and introduced to the United States during the 1960s) and V. riparia (MN 89). The advantages of using V. riparia in breeding are its cold hardiness and disease resistance. Indeed, Frontenac is a vigorous vine that is extremely hardy—it can survive winters that drop below -20°F. It is also a vine that doesn’t require much treatment against grape diseases, so it’s perfect for organic and backyard growers. It’s also fairly high yielding, with 10-15 pounds per vine easily obtained.

Nonetheless, its wild ancestor produces grapes that are very acidic and highly pigmented. These traits passed down to Frontenac, along with high sugar production, can yield grapes with fruit chemistry that is challenging to work with in the winery. The Brix ranges from 24° to 28°, and total acidity ranges from 10 to 15 grams per liter. However, its aroma profile of intense cherry, black currants and chocolate can make for a pleasing wine when there is a good balance between sugar, acid and alcohol. In some cases, herbaceous notes of green beans, cut grass and evergreen can emerge in Frontenac wines. Many winemakers are finding success in using the wine to make a fruit-forward, off-dry rosé and dessert-style wines. Fortified dessert wines are also a very popular style for Frontenac grapes.

Although breeding with V. riparia can produce offspring with challenging fruit chemistry for a winemaker, the advantage in breeding is that it has none of the “foxy” or “grapey” aromas that are sometimes associated with hybrid grapes. Although wines have been produced from Concord and Catawba for generations, they have not caught on with the general wine-drinking public who are more accustomed to drinking European wines or wines made from European grapes. Nonetheless, a table grape named Edelweiss, developed at the University of Minnesota by grape breeder Elmer Swenson, has shown much success in the Upper Midwest as a wine grape, and it is popular in tasting rooms. Wine grapes made with V. labrusca-based hybrids are typically harvested early in order to minimize the impact of the foxy aroma on the overall bouquet of the wine.

Since the release of Frontenac, there have been two single-bud mutations within the vine that have yielded less-pigmented fruit. The Frontenac family of grapes now includes Frontenac Gris and Frontenac Blanc. Both of these grapes tend to yield fruit with similarly high sugar and high acid chemistry to the original “noir” vine, though this fruit chemistry works well to make crisp white wines. It also makes them rather versatile in the winery, and often they are used to make off-dry white wines and intense dessert wines. The acidity works particularly well to balance sweet wines and prevent them from being too cloying. The aromatic profile of Frontenac Gris is very fruit forward, with notes of apricot and peach dominating. Frontenac Blanc also tends to have some tropical fruit characteristics along the lines of pineapple and peach, with some grassy herbaceous notes that are reminiscent
of a Sauvignon Blanc.

The first white grape cultivar released by the University of Minnesota, La Crescent, is a complex hybrid containing 45% V. vinifera in its heritage (which includes Muscat Hamburg) and 28% V. riparia along with four other species of grapes including V. labrusca. The important attribute of La Crescent is its floral Muscat flavor.

La Crescent vines are more susceptible to downy mildew than Frontenac and have a procumbent growth habit that makes those vines suitable for high-cordon trellising in the vineyard. Also a high-acid cultivar (average total acidity is 11.9 grams per liter), it is well suited as an off-dry aperitif wine. It also has shown well as a dessert wine, though the grapes are susceptible to shelling, so late-harvest styles are not typically seen.

The latest release from the University of Minnesota, Marquette, has raised the bar for quality wine production in the upper Midwest and Eastern states. A high-sugar, moderate-acid grape, it produces a light-bodied red wine with good dark berry fruit and black pepper characteristics in certain wines. It is low in tannin yet retains a garnet color that ranges in intensity depending on the vintage and vineyard site.

The flavor profile of some wines can be reminiscent of Pinot Noir, with the cherry and spice characters, while other wines can gain deep, concentrated berry and spice aromas reminiscent of a Zinfandel. Marquette was released in 2006, so the first true vintage that growers had to work with the vine was in 2009. As growers and wineries learn more about best vineyard and winery practices with this new cultivar, it has the potential to produce excellent light-bodied reds.

The University of Minnesota is not alone in the development of new grape cultivars for the Upper Midwest, as private breeders and other universities such as Cornell also are developing new cultivars. As breeding for cold-hardy grape cultivars continues, the limits to where grapes can be planted and grown continue to expand. While it may take some time for consumers to become accustomed to drinking wines made from new cultivars, the variety of flavors seen in these new grapes is exciting to those of us who are looking to explore new wine varieties and regions around the world.
—Katie Cook 

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