As winter settles in, there’s one harvest of the year left for a handful of vineyards in Michigan: an ice wine grape harvest.
Ice wine is tricky to pull off and can only be made in regions with just the right weather conditions. It entails leaving grapes on the vine until they freeze and picking them by hand once the temperatures drop to roughly 15 to 18 degrees Fahrenheit for at least 24 to 48 hours. The grapes are then pressed immediately while frozen.
The result is grape juice with a very high sugar concentration — potentially twice as sweet as juice from grapes harvested in the fall — that is turned into a rich, sweet dessert wine.
“In the U.S. and in our industry here, if we’re going to call something an ice wine, it’s supposed to be fruit that is frozen on the vine, picked frozen, pressed frozen,” says Lee Lutes, head winemaker for Black Star Farms in Suttons Bay. “And you have to have almost perfectly ideal conditions for that to happen.”
Such conditions have become rarer in Michigan in recent years, and this season’s unusually warm December and January have meant some wineries haven’t had a chance yet to harvest grapes for ice wine — or have chosen to forgo it this winter entirely.
“We’re really just waiting for Mother Nature to cooperate with us,” says Kyle Brownley, director of marketing at Chateau Chantal on the Old Mission Peninsula. He says Chateau Chantal will pick frozen grapes any time from late December to March depending on the temperatures, but harvest typically takes place in early January. This year, the winery hasn’t experienced cold enough weather yet.
Some years, it never gets cold enough.
“That’s one of the inherent risks with ice wines,” Brownley says. “So on top of it being something you can only do in very specific regions, where you have a warm enough summer to get enough sugar built up that it’s worth allowing [grapes] to freeze on the vine, you also have to contend with years that it’s just not going to happen.”
Fortunately, there’s still plenty of time left this season for the proper conditions to develop.
Chateau Chantal makes a variety of ice wines that range from traditional to unique. The winery’s classic Estate ice wine is made from a blend of white varietals, while its Cabernet Franc ice wine is a more uncommon offering that the winery has introduced in the last few years.
“You don’t see as many red varietals being used as ice wines, but it’s something that we’ve really enjoyed since we’ve been able to produce it,” Brownley says.
The staff plan to harvest grapes for both wines this year. The winery also sometimes makes a Vidal ice wine and a port-like ice wine called Entice, which is fortified with grape brandy.
Challenges in the Cellar
In other parts of the state, the ice wine harvest has already taken place. At Domaine Berrien Cellars in Berrien Springs, frozen grapes were harvested in late December.
“We were picking in the middle of the winter storm that came in right before Christmas,” says Amy Birk, winemaker and operations manager at Domaine Berrien. “So it was rather cold. We were out there in the 50-mile-an-hour winds down here.”
Despite the difficult conditions, she says, the harvest went “extremely well.”
“It was a really good harvest,” she says. “We had great freezing and great juice quality come out of the fruit.”
Altogether, the team pulled in just over 2 tons of frozen Cabernet Franc grapes. They ended up with roughly 100 gallons of grape juice, which is now fermenting. The winery plans to bottle the wine in the summer and release it in the fall.
Domaine Berrien has been producing Cabernet Franc ice wine since 2004 and is no stranger to the challenges of making ice wine.
In addition to the concerns about weather as well as continued pest and disease pressure as grapes are left on the vine, once the frozen grapes are picked, they’re difficult to press and yield much less juice than unfrozen grapes.
“Usually, 1 ton of grapes will yield you about 160 gallons of wine,” Birk says. “With ice wine, you’re typically getting only one drop of juice per berry, so it’s a very low extraction.”
To squeeze even that single drop of juice out of each grape requires special equipment.
“You need a high-pressure press in order to press frozen grapes,” Black Star Farms’ Lutes says. “These things are like marbles when you bring them in.”
Winemakers will often use a hydraulic basket press for making ice wine instead of a standard press. While a standard press will apply a force of about 5–10 pounds per square inch to press grapes, Lutes says, a high-pressure basket press will apply a force of about 300–400 pounds per square inch.
Fermenting the resulting juice is also a challenge because of its high sugar level.
“It’s almost like maple syrup, because what you’re doing in the freezing process of the grape is you’re concentrating the sugar that remains in that grape,” Lutes says. “All the water stays in the grape as a water crystal, but the liquified sugar is what you basically squeeze out of the berry. Now you’ve got something that’s very sweet, very concentrated, and yeasts don’t like that environment.”
To get the fermentation started, winemakers add yeast to a very small portion of the juice to create a “mother” yeast, and then they slowly combine that mixture with the rest of the juice, Lutes says.
Even once fermentation has begun, it’s a slow process. Black Star Farms bottled its 2021 vintage of ice wine on Jan. 10, about one year after grapes were picked. Supply chain issues delayed the bottling somewhat, but it’s typical for ice wine fermentation to take months.
The winery’s Riesling ice wine, called A Capella, will likely be released in late winter or early spring. It will be Black Star Farms’ first true ice wine since 2013; in fact, ice wine has only been made a handful of times in the winery’s 25-year history, including a previous vintage that was served in the White House.
Celebrating the Season
While some wineries wait for their ice wine to ferment and others wait for a cold snap in order to harvest their grapes, Chateau Chantal is celebrating the ice wine season with its fifth annual Ice Wine Festival.
On Jan. 28, wine lovers can sample several of Chateau Chantal’s ice wines — including different vintages of different wines — as well as take an ice wine vineyard tour and an ice wine-focused cellar and production tour. Visitors can also participate in throwing snowballs at Head Winemaker Brian Hosmer to earn special discounts. (“As you can imagine, most of the staff is pretty excited about that one — that should be fun,” Brownley says.)
The festival culminates in the Fire & Ice Wine Dinners on Jan. 27 and 28, which are offered only one weekend a year and demonstrate the potential for pairing ice wine with food.
In all, the festival highlights how special it is for Michigan wineries to be able to make such a rare and decadent beverage — a true testament to Michigan’s place in the world of wine.