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When you’re freezing and stranded in two feet of snow, winter can really get you down. However, some winemakers count on extremely cold weather to make deliciously sweet wines.
As winter storm Nemo pounds the Northeast with two feet of snow this weekend, it can be hard to see the silver lining of wintery weather.
And though peering out a window in February might make you want to hibernate until June, the extreme conditions of a northern winter create the perfect natural incubator for a delicious sweet and boozy treat: ice wine.
Ice wines, which originated in Europe as “Eiswein”, are produced from ordinary varieties of wine grapes – like Riesling or Vidal – which are left on the vine until winter, then pressed when frozen, and fermented as usual. The resulting liquid isn’t a crisp libation you’d serve with a delicately seasoned sea bass; it’s a syrupy, sweet dessert wine.
But wait a minute: how exactly do bitter cold temperatures result in sweet wines?
Freezing temperatures concentrate a grape’s natural sugars, says Eric Heavilin, winemaker at Fenn Valley Winery in Fennville, Michigan. And when frozen grapes are pressed, the water inside the grape remains frozen, while the condensed sugars flow out in a thick, syrupy liquid.
“Instead of getting a juice that is normally 22 percent sugar, you can get juice that is upwards of 45 percent sugar,” Heavilin says.
However, the tradeoff for extra sugar is reduced volume. Pressing frozen grapes takes longer than traditional winemaking, and the process yields only about one-third of the juice volume, Heavilin says. Unfortunately for consumers, this extra effort is reflected in the price tag: by volume, ice wine costs about twice as much as its less sugary counterpart.
To produce a true ice wine, Heavilin says that grapes must be grown in cold regions – like Michigan, upstate New York, and Ontario – and can only be harvested when outdoor temps dip below 17 degrees Fahrenheit.
But where there is money to be made, shortcuts abound. Due to unseasonably mild winters and rising demand for ice wine, some winemakers have turned to a copy-cat method called cryoextraction, freezing grapes indoors after they’ve already been picked from the vine.
During cryoextraction, the sugars are still concentrated within the grape, but Heavilin says that there’s something special about wine from grapes that have frozen naturally on the vine. “There are a number of things that happen when the grape is still on the vine, as far as aging and maturity, and you can’t get some of the same flavors if you just pick them and put them in the freezer,” he says.
Well, at least this miserable winter weather is good for something.