The wine gets its sweetness because grapes contain more water than sugars, according to Ferrante. The sugar becomes concentrated once the water is frozen, leading to a syrupy consistency.
Ferrante said it picked 12 tons of Vidal. The wine will be fermented to 15 percent residual sugar and bottled in the spring. Sekerak said the winery normally gets about 100 gallons out of a harvest but said she doesn't know if it'll be the same this year.
Wineries stretching from Minnesota through New York and in parts of Canada have waited nervously for temperatures to drop low enough to harvest the fruit. Many were finally able to do so, but winery operators say the delay resulted in far fewer usable grapes.
"What's ironic about the ice wine harvest is it's one of the few times when people actually say, 'Great, it's going to be bitter cold,'" said Jim Trezise, president of the New York Wine and Grape Foundation. "We were kind of twiddling our thumbs, but it finally came together."
Federal regulations prohibit using the "ice wine" label unless the product came from grapes that were at least partially frozen on the vine. But much can go wrong. The longer the harvest is delayed, the greater the risk that grapes will rot or shrivel past the point of usefulness. Some growers who have managed to harvest ice wine grapes say their yields were down by as much as 40 percent this year compared to a typical harvest.
Grapes left on the vine for extended periods also are more likely to be eaten by birds, deer, raccoons and other wildlife. Some growers shield the fruit with nets and install noisemaking devices, but the critters are resourceful.
Sleet and hail can damage the grapes. If too much snow falls, it can bury low-hanging bunches, making them hard to retrieve.
"I'm delighted if we can harvest 50 percent of what we left hanging for ice wine," said Mark Johnson, winemaker at Chateau Chantal winery on Traverse City's Old Mission Peninsula. That's about what his operation managed to take in last week on the half-acre set aside for the purpose.
Delaying the harvest also can stress vines and stunt production for a year or two, said Edward O'Keefe III, president of nearby Chateau Grand Traverse, which sometimes makes ice wine but took a pass this season.
All those risks - and the fact that it can take three or four times more grapes to make a bottle of ice wine than ordinary wine - explain the high price tag. Chateau Chantal charges $68 for a 375-milliliter bottle, which is half the size of a standard wine bottle. Some ice wines sell for $90 or more.
"It's just something really special, something to be sipped and savored," Johnson said. "You're not going to kick back and chug a tumbler full. You want an ounce or a half-ounce."
Ice wine is a niche product, accounting for less than 5 percent of the wine made in Michigan, said Linda Jones, director of the Michigan Grape and Wine Industry Council. In New York, it makes up just 1 to 2 percent, Trezise said. So even if a winery loses all its ice wine grapes one year, it's unlikely to be ruinous.
Still, it's an important marketing tool for the northern wine industry - an item that warm-weather competitors can't match.
"If you're known for something that's really special and rare, it helps build your reputation," Trezise said.
Ice wine usually is made with white wine grapes such as Riesling and Vidal, although the red variety Cabernet Franc is another frequent choice. It originated in Germany in the late 1700s and remains popular there. Canada is a leading producer, especially the Niagara region of southern Ontario.
Some Canadian vineyards got cold enough briefly in late December to harvest. Crews in Nova Scotia spent Christmas Eve in the vineyards, industry spokeswoman Christine White said. Henry of Pelham Estate Winery in St. Catherines, Ontario, took advantage of a short freeze the night of Dec. 29, said its president, Paul Speck.
"We had about seven to eight hours that were perfect to pick in," Speck said. "We were happy to get what we could. It's been ridiculously mild here."
For many operations, the window of opportunity finally came last Tuesday, when a cold spell settled across ice wine country. Workers jumped into action after dark at Lemon Creek Winery in Berrien Springs, Mich. Aided by a harvesting machine, they secured about 4 tons in a couple of hours.
The haul was less than half of what it would have been in early December, owner Jeff Lemon said. But it could have been worse.
"This was the latest we've ever gone," he said. "We were one evening away from ending up with nothing."
Sekerak said it becoming more popular.
''People are becoming more educated about it and can appreciate it more, either by itself or to cook with,'' she said.
Ferrante uses its Vidal Blanc ice wine in making whipped cream used on fruit cobbler made at the winery or on pumpkin mousse during the holidays.
''As we say at the winery, it's life's simple pleasure meant to be shared,'' Sekerak said.
