Grape Guide
Frontenac
RedFrontenac is a black-skinned, cold-hardy hybrid released by the University of Minnesota in 1996, and it became the most widely planted red variety in that state. It survives winters that kill European vines, resists downy mildew, and gives deeply coloured wines of cherry and plum fruit, though its acidity runs very high.
Key characteristics
- Interspecific hybrid of Landot noir and a wild Vitis riparia selection
- Reported hardy to about minus 35 F (minus 37 C)
- Highly resistant to downy mildew, resistant to powdery mildew and botrytis
- Vigorous and productive; the clusters are open and carry berries that run from small to medium in size
- Very high acidity and high sugar potential; susceptible to foliar phylloxera
Typical flavors
Major regions
Minnesota · Iowa · Wisconsin · Illinois · Quebec · Vermont · Nebraska
Also known as
MN 1047
Frontenac is the founding variety of the University of Minnesota's cold-climate wine grape programme, and it allowed commercial viticulture in places where winter lows had long ruled out European vines. The vine tolerates temperatures near minus 35 F, crops generously, and shows strong resistance to the fungal diseases that make wet continental summers difficult for vinifera.
In the glass it is a dark, intensely coloured red with a core of black cherry and blackcurrant, sometimes plum, and a savoury or chocolatey note as it ages. It lacks the pronounced foxy character of many native American hybrids. Its weakness is acid: levels in the berry can stay very high at harvest, so winemakers rely on late picking, malolactic conversion, residual sugar or fortification to bring balance. Two colour mutations, Frontenac Gris and Frontenac Blanc, extend the family into white and rosé styles.
Frontenac came out of the University of Minnesota, bred by a team made up of James Luby, Peter Hemstad and Patrick Pierquet. The cross dates to 1978 and joins Landot noir (also known as Landot 4511) with Vitis riparia selection number 89, a native riverbank vine reported to have been gathered in the wild close to Jordan, Minnesota. The resulting seedling, coded MN 1047, was chosen in 1983 and became the university's first named wine grape on its release in 1996.
Landot noir is itself a French hybrid, raised by Pierre Landot in the department of Ain from Landal noir crossed with Villard blanc (Seyve-Villard 12-375). Seibel crosses lie behind both of those parents, so Frontenac inherits a blend of vinifera and several American species (riparia, rupestris, labrusca, aestivalis and berlandieri). The pedigree is usually summed up as roughly half Vitis riparia and half Landot noir. VIVC catalogues the variety under number 15904.
Two mutations came afterwards. Frontenac Gris is a grey-skinned bud sport that Hemstad first noticed in 1992; it was released in 2003 and was protected by a University of Minnesota plant patent (now expired), though propagation is still licensed. Frontenac Blanc is a white-fruited sport. It turned up in 2005 in a vineyard at Dunham, Quebec, and was found in Minnesota later on. Accounts differ on who first propagated and released it, and the university shows it as available from 2012.
Frontenac is vigorous and productive, with moderately early budbreak and mid-season ripening. The bunches are loose, made up of small to medium berries that can reach high sugar and high acidity together. Cold hardiness is its defining trait: figures of about minus 33 to minus 35 F are reported, and growers in Vermont have recorded full crops after dips near minus 30 F. Resistance to fungal disease is strong, with near immunity to downy mildew and good tolerance of powdery mildew and botrytis, which permits low-spray management. The main sanitary weakness is susceptibility to the foliar form of phylloxera, which can disfigure leaves. Loose clusters help airflow and limit rot, but the combination of generous yields and persistent acidity means crop control and late harvest are the usual tools for improving quality.
Frontenac is made in several distinct styles. Dry reds are deep in colour with cherry, blackcurrant and plum fruit, but the high acidity can make them sharp unless the wine is blended, aged on oak, softened by malolactic fermentation or finished with a little sugar. Rosé is common, since the acid structure suits a fresh, fruity style. Port-style fortified wines are increasingly popular because late-harvested fruit loses some of its acidity and gains sugar, and the dark colour and cherry-chocolate character carry well into a sweet fortified wine. Frontenac Gris yields white or lightly tinted wines with peach, apricot and citrus aromas and bright acidity, usually off-dry or sweet. Frontenac Blanc is valued for clean, untinted whites, and its most fitting uses are dessert and port-style bottlings. Lower-acid reds such as Marquette have taken some of the dry table wine market.
Where it grows
Minnesota
Home of the variety and historically its most planted red grape, with about 47 hectares recorded in 2007. Frontenac Gris added roughly 30 hectares in the same survey, and the state supports varietal bottlings of all three colours.
Iowa, Illinois, Wisconsin and Nebraska
The northern Midwest adopted Frontenac early, with Illinois at about 23 hectares, Iowa about 19 and Nebraska about 6 in surveys from 2006 and 2007. It is used for reds, rosés and fortified wines.
Quebec
Frontenac is a leading red variety in the province's cold-hardy vineyards, with around 21 hectares recorded in 2009. Frontenac Blanc was first spotted here in 2005, and Gris is also grown.
Vermont and the Northeast
Listed among the wine grape cultivars established in Vermont vineyards, where its winter hardiness allows production without burying vines. Gris and Blanc are also planted in New England and New York.