Ice wine

Ice wine 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 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".

Ice wine production is risky (the frost may not come at all before the grapes rot or are otherwise lost) and requires the availability of a large enough labor force to pick the whole crop within a few hours, on a moment's notice, on the first morning that is cold enough. This results in relatively small amounts of ice wine being made worldwide, making ice wines generally quite expensive.

Ice wine production is concentrated in Canada and Germany, but has been reproduced in other cold climates, for example in northern U.S. states and in China.

History

Ice wine was first produced in Germany in the late 18th century. However, there are indications that frozen grapes were used to make wine in Roman times. Pliny the Elder (AD 23–79) wrote that certain grape varieties were not harvested before the first frost had occurred. The poet Martial (AD 40–102) recommended that grapes should be left on the vine until November or until they were stiff with frost. Details as to the winemaking process and how it was made are not given.

Production

Ice wine's production requires that the grapes are naturally frozen on the vine. Picking usually happens in the early morning hours before sunrise, at temperatures between −8 and −12 °C (17 and 10 °F). The grapes are then pressed while still frozen, leaving the frozen water crystals behind and extracting only the sugar-laden juice. Since the juice is so sweet, the fermentation process takes several months.

Regions

The largest producers of ice wine are Germany and Canada, particularly the Niagara Peninsula in Ontario which has ideal conditions for producing ice wine. The United States also produces ice wines, particularly in the Great Lakes region and in the Finger Lakes region of New York State. China has grown in prominence as a producer of ice wine, particularly in the Liaoning province.

See also

• Late harvest wine
• Noble rot
• Straw wine
• Sauternes (wine)

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