September 21, 2017

Frontenac Outgrows Wild Youth

The Frontenac wine grape started with a graduate student on a canoe trip.   While paddling through the suburbs of Minneapolis during 1976, a University of Minnesota graduate student named Patrick Pierquet found the wild parent of Frontenac growing along the Minnesota River.  (Pierquet is now the enology wine lab manager at Ohio State University in Wooster.)
On the left, Riparia 89, the wild parent of Frontenac, compated with a modern Frontenac cluster on the right.

On the left, Riparia 89, the wild parent of Frontenac, compared with a modern Frontenac cluster on the right. Photo: Patrick Pierqet


Back at the University of Minnesota, plant researchers Jim Luby, and later Peter Hemstad, combined Pierquet’s wild grape cuttings with a French hybrid called Landot. The result was Frontenac; the University of Minnesota’s first licensed wine grape which was released in 1996.

Frontenac’s wild grape parentage has turned out to be both a blessing and a curse.  Wild grapes are cold hardy and disease resistant, but they can also be small, bitter and acidic.

For these reasons, Frontenac initially took some guff from winemakers.  The University even released what could be considered Frontenac’s red replacement (the Marquette grape) during 2006.

Despite its shortcomings, Frontenac is now widely planted in the Midwest and makes many popular wines.    According to Hemstad at the University of Minnesota, “If you’re starting a vineyard in a colder area, I would recommend Frontenac. It’s a workhorse variety that’s also very forgiving in the field. “

The relative ease with which Frontenac grows in the Midwest and Northeast U.S. makes it a standout in the vineyard.   On the other hand, making wine from Frontenac can be more difficult than some other hybrids.   “Normal” acidity for Frontenac is around 2.9 pH and 15 g/L titratable acidity, which is hardly normal.

MI wine barrel adBut Midwest wine makers are learning to tame this cultivar with Minnesota dirt in its blood and wine quality has improved dramatically.  Winemakers and grape growers are now working successfully with Frontenac in a number of styles and wine consumers are enjoying the results.

Dry Frontenac is rare in the upper Midwest because of the grape’s high acidity in cooler climes.  However, central Midwestern grape growers are making very palatable Frontenacs in a dry or off dry style.  Hemstad agrees that a character difference exists between Frontenac grown at 45 degrees north and 42 degrees north. (This is roughly the latitude difference between Minneapolis and Chicago.)

John Larson of Snus Hill Winery in Madrid Iowa, northwest of Des Moines, has 2.5 acres of Frontenac which he planted in 2000.  In addition, he gets Frontenac from other local growers.   From these grapes, Larson makes both a dry, 100% Frontenac wine and a port style dessert wine.

John Larson of Snus Hill Winery in

John Larson of Snus Hill Winery in Madrid Iowa

Larson split this year’s harvest, which was picked during late September, into press fractions. He reports that to his surprise, the free run Frontenac juice had almost vinifera like chemistry: “The free run had a pH of 3.9 and a t/a of 7,” he says. Larson, who moved to Iowa from California, went on to say with a laugh, “The Frontenac this year is almost like it came from the West Coast, I might actually have to add some tartrates to the wine.”

So how does Larson explain the low acidity of his Frontenac? “The big issue with Frontenac is not to pick it early,” Larson says.   “You need to let it hang so the acids have time to drop.  The sugar levels will get high and it can take what seems like forever for the acids to come down.”  (The Brix for Frontenac can reach the upper 20’s.)

This year’s low acid Frontenac was something of an anomaly, Larson says.   So he keeps an arsenal of decacidifaction weapons at the ready.  These include malolactic fermentation, cold stabilization and perhaps chemical deacidification in the form of potassium bicarbonate.

Larson’s dessert wine, which won Double Gold at the 2013 Iowa State Fair Wine Competition, has a residual sugar level of 16%.  Such high sugar levels are not uncommon in Frontenac dessert wines because substantial sweetness balances the acidity of the grape nicely.  It’s a testament to the power of Frontenac’s river grape parents that a wine with as much sugar as Coca Cola can be well balanced.

In the cold hardy red hybrid category, Frontenac competes with Foch and the aforementioned Marquette.  Larson said he prefers Frontenac to Foch because Frontenac  is less herbaceous.

“Frontenac kind of reminds me of Barbera,” he says.  “It has high acid and high sugar with a single note flavor of dark fruits like cherries and raspberries.”

Another early adopter of Frontenac is Massbach Ridge Winery in Northwest Illinois near Galena.  For Peggy Harmston of Massbach Ridge, 2013 is the tenth anniversary of making Frontenac.  She started with 150 vines in 2000 and has three acres now.

Peggy Harmston of Massbach Ridge Winery in

Peggy Harmston of Massbach Ridge Winery in Elizabeth, Illinois

Massbach Ridge makes two semi dry Frontenac wines.  The first is Traumen, which is German for “dream.”  It has 1.5% residual sugar and does not go through malolactic fermentation.   Soft tannins give the wine a perception of sweetness, Harmston said.

Traumen won a Double Gold Medal at 2012 Illinois State Fair Wine Competition.   “It’s a very popular wine,” Harmston says.  “So popular that we’ve run out in some years.”

Her other Frontenac is called Massbach Reserve.  It has only .4% residual sugar.  Blending about 10% Foch helps balance Frontenac’s acidity in the Reserve wine, Harmston says.

Harmston lets Frontenac ferment on the skins for 3-5 days to get a rich color.  “When I press it off, it’s almost done fermenting,” she says.

Making generalizations about Frontenac winemaking is difficult, Harmston says.   She evaluates her grapes every year and then decides if measures like deacidification or aggressive cold stabilization are needed.

In the vineyard, Massbach Ridge has Frontenac on a singe wire trellis at just over five feet so the grapes are easy to pick.

Giving vigorous Frontenac vines room to spread is advised.  Harmston keeps her vines about eight feet apart with 12 foot separations between rows.

According to Hemstad, Frontenac can be prone to over cropping.  Dropping fruit is often necessary to achieve proper grape quality.

Acids will be more manageable if the clusters are exposed to sunlight, Hemstad says.  Therefore, growers can expect to perform leaf pulling during the growing season.

Where the growing season is the shortest, Frontenac stands out the brightest.  In regard to cold tolerance, all one really needs to know is that Minnesota winters don’t usually harm Frontenac.

One of the first Minnesota wineries to bottle Frontenac is St. Croix Vineyards near St. Paul Minnesota.  According to Matt Scott at St. Croix, Frontenac is the winery’s top selling red wine. St. Croix Vineyard produces 1,000 to 1,500 gallons of dry Frontenac annually, and the winery also makes a Rosé and a Port from Frontenac.


Martin Polognioli of Saint Croix Vineyards

Martin Polognioli, the production manager at Saint Croix explains, “We grow Frontenac on a high cordon trellis with one and two trunks. It’s a vigorous grower and fruit producer and does not require a lot of work once it is trained onto the trellis. Some hedging, shoot and leaf thinning is done in the summer to increase sun exposure.”

Polognioli uses oak in his style of Frontenac winemaking.  “We age the Frontenac in barrels for about a year, sometimes a little longer. The barrels are American and hybrid (French-American) ranging from new to four or five years old.”

While Saint Croix Vineyards ages their Frontenac in oak barrels, Mary Mohn of Flower Valley Vineyard, located in Red Wing, Minnesota, aged their 2011 Frontenac in steel barrels.  Steel barrels, are more economical and oak flavoring is added to each batch.

Years from now, we may look back at Frontenac as one of the University of Minnesota’s early attempts to create a cold tolerant red wine grape.   Hemstad hinted that a new Frontenac may be in the works when he told Midwest Wine Press, “We have derivatives of different fruit that will be introduced in the future.”

In the meantime Frontenac continues to be one of the Midwest’s red foundation wines.  It’s the second most widely planted red wine grape in both Wisconsin and Minnesota. (Marquette is #1.)

“In the upper Midwest, it seems like there’s always some new red grape of the future,” Larson of Snus Valley said. “Frontenac has a definite place here; it will survive and make good wine in this climate.”

Theresa Preston is currently a VESTA viticulture student   She’s on a mission to enlighten others about the wonderful cold-hardy varietals of the Midwest!













  1. Just for the record, the first photo above(showing the two grape clusters) was taken by Tom Plocher, a Minnesota grape breeder and(as many people know) the originator of the Petite Pearl grape variety.