Grapes frozen on the vine produce ice wines, which generally have a crisper, clearer taste than other sweet wines, says Malachy Duffy...
If you enjoy gardening, you know how important it is to pay attention to growing zone maps that dictate when it is safe to plant to avoid late frosts. But in the world of wine, there is a rarefied niche where the dreaded temperature plunges are crucial. The resulting wines earn the poetic name “ice wine.” Ripe grapes are allowed to freeze on the vine, which separates out the water from the flavoured elements, so when the grapes are crushed, they yield a sweet and concentrated must (juice). This is then fermented to make a product that can stand proudly in the pantheon of sweet wines.
Most of the better-known sweet wines, such as Sauternes or Tokaji, owe their existence to the development of a late-season mould, botrytis — the noble rot — that concentrates the sugar. But grapes that are used in making the botrytis-based sweet wines are not used for making ice wines. The latter require healthy grapes that remain in good shape on the vine until the freeze arrives. This gives ice wine its characteristic refreshing sweetness balanced by high acidity.
The production of ice wines is challenging, as temperatures might not drop low enough before the grapes begin to deteriorate. So it is not surprising that the geographic range of production is limited, the prime regions being the perhaps less obvious wine tasting locations of Canada, Germany and, increasingly, the United States. Unlike other sweet wines that can be served at different stages of a meal, ice wines are best served afterward, having been chilled for no more than an hour in a refrigerator. Here's how to buy the best wine for your superyacht...