Ice wine (or icewine; German Eiswein) is a type of dessert wine produced from grapes that have been frozen while still on the vine. The sugars and other dissolved solids do not freeze, but the water does, allowing a more concentrated grape must to be pressed from the frozen grapes, resulting in a smaller amount of more concentrated, very sweet wine. With ice wines, the freezing happens before the fermentation, not afterwards. Unlike the grapes from which other dessert wines are made, such as Sauternes, Tokaji, or Trockenbeerenauslese, ice wine grapes should not be affected by Botrytis cinerea or noble rot, at least not to any great degree. Only healthy grapes keep in good shape until the opportunity arises for an ice wine harvest, which in extreme cases can occur after the New Year, on a northern hemisphere calendar. This gives ice wine its characteristic refreshing sweetness balanced by high acidity. When the grapes are free of Botrytis, they are said to come in “clean”.
Due to the labour-intense and risky production process resulting in relatively small amounts of wine, ice wines are generally quite expensive.
Canada and Germany are the world’s largest producers of ice wines. About 75 percent of the ice wine in Canada comes from Ontario.
There is also a sparkling version of ice wine. Sparkling ice wine was created accidentally in 1988, by Canadian wine writer, Konrad Ejbich, in his home cellar, using tank samples of the previous year’s ice wine, from the Inniskillin winery in Ontario. In 1996, finally acknowledging he could not produce this product himself on a commercial basis, Ejbich decided to share the concept. He wrote about his experience with sparkling ice wine in his column in Wine Tidings magazine, challenging Canadian wineries to make sparkling ice wine on a commercial basis. The Magnotta winery in Ontario filled a 50-litre metal beer barrel with ice wine, carbonated it, and called their product the first commercial sparkling ice wine. However, Ontario’s Vintner’s Quality Alliance (VQA) would not give the product its stamp of approval because no such category existed in its regulations. In 1998, Inniskillin Wines produced the first charmat method sparkling ice wine. The VQA approved Inniskillin’s product because it was not made using carbonation.