This German tradition of Eiswein has become more and more popular in the Nordic countries, as well as the cold regions of the U.S. and Canada. Some grapes live well beyond the autumn, hanging on to the vines well into winter and the first real frosts. These are the grapes used to produce Eiswein, the iced wine that’s becoming increasingly popular among consumers.
Legend has it that it was first—and accidentally—made in 1830 during a great famine that struck the German region of Rheingau, on the banks of the Rhine river. In order to keep their livestock alive, residents decided not to pick all of the grapes during the harvest, leaving some on the vines so their animals could eat them during the winter months.
A few curious Germans, however, tried to make wine from these frozen grapes and found the result to be delicious and sweet: when frozen, the sugar content increases to about 250 grams for every liter of wine, which makes a pleasing contrast to the acidity of the grapes. Freezing actually prohibits the formation of the noble mold, botrytis cinerea, that mitigates acidity in normal wines. And this is the primary, but crucial, difference between Eiswein and similar sweet wines like Sauternes and Tocaj. And it’s this balance between sweetness and acidity that makes Eiswein suitable for pairings with both sweet and savory foods, especially cheese.
The method survived for more than a century before being definitively concretized: there was, in fact, no official production of Eiswein before 1961. Since then, however, it’s been enjoying a slow but constant rise: first taking hold in Germany and Northern Europe, it then spread West, across the Atlantic, where it was embraced by Americans and then Canadians—who, after Germans and Austrians, have now become the world’s largest producer of the wine.
The grapes used in for Eiswein are mainly Riesling, Vidal and Seyval Blanc for the whites, and Cabernet Franc for reds, although experiments with varieties like Gewurtztraminer, Chardonnay, Pinot Grigio have produced excellent results. Labor intensive to make, and therefore not cheap (prices start at 25 dollars per bottle and go up from there), it’s become an important, though high-risk sector in frigid areas. The grapes have to stay on their vines for an extra three months, which exposes them to all kinds of damage, and are only picked once the temperature has fallen well below zero.
The pressed grapes must then remain for at least two days at 15°C before the fermentation process can begin. This long and labor intensive process has caused some producers to invent short cuts, namely an artificial freezing of grapes that are picked in the autumn. This causes the price to fall and enables the product to reach other consumers.
The final product, of course, is different and of inferior quality. In North America, where the dispute between traditional and faster methods is becoming more controversial, the laws dictate that the appellate Ice Wine can only been given to a product whose grapes have been frozen on the vine; the other products may be called with the easily-confused names of Iced Wine or Ice.
The traditional method, while extremely risky for producers and expensive for consumers, is proving valuable for the efforts of winemakers. Production is increasing, and more and more restaurants and wine bars are offering glasses of Eiswein, to the delight of epicureans everywhere.