Along with parts of Germany and Austria, Canada is the premier producer of one of the world's rarest oenological birds: Ice wine, also known as eiswein, made from grapes left to freeze on the vines. Growers in New York and Michigan also take advantage of their chilly climes to make ice wines.
How Is Ice Wine Made?
Grapes are left on the vine into winter. As they freeze, the sugars concentrate. Very little juice is then extracted when the semi-dried frozen grapes are pressed. What does result is cold-fermented to produce an amazingly sweet, smooth, and fruity nectar. The time-consuming, low-yield method leads to high prices, and half bottles from well-established wineries fetch $75-$150.
Ice wines are most commonly made from grapes with a high acidity—Riesling, Vidal, Gewurztraminer, and Cabernet Franc—that will keep the final ice wine from getting sickly sweet and keep a refreshing back note that lends fine ice wines their elegant nature.
Variations on Ice Wine
Some wineries in less cold areas use freezers to bring their grapes to a similar state. The more ethical of them use terms like vin de glacière (ice box wine) to denote the difference between their results from artificially and quite quickly frozen grapes from the long, slow process of leaving grapes to hang on the vine well past the regular harvest to twist and turn in the wind as the air turns frigid.
Because harvesting frozen grapes is a less-than-pleasant task, some ice wine producers harvest the grapes before the freezing air sets in and hang them in nets along the vines where they would have hung anyway (as pictured) but can be easily collected once the weather has frozen the grapes long enough. Opinions, as you might imagine, differ on whether this early-harvest method makes a difference in the final ice wine.
How to Serve Ice Wine
Ice wines are sweet and work best as dessert wines. While they share a balanced sweetness one finds it dessert wines made from grapes exposed to botrytis, ice wine grapes are not, in common practice, exposed to rot or fungus. The idea is that they freeze before rot sets in. They simply freeze, slowly in open air, and that concentrates their sugars enough to create the intensely sweet and wonderfully textured taste characteristic of the best ice wines.
Serve ice wine lightly chilled, in small glasses, like port glasses, or white wine glasses. Serve ice wine on its own or with slightly lighter, slightly less-sweet desserts. Ice wines tends to work very nicely with aged cheese.
Just because they're sweet doesn't mean ice wines need to be consigned to dessert. Their complexity and body tends to work very well with foie gras and other highly rich, fatty foods.