Eiswein, one of the most valued German sweet wines, has its origins at the beginning of the 19th century during a rather poor wine year in Germany. Many grapes were not harvested due to the poor quality. They should only be fed to the cattle in winter after a few frosts. In the process, German winemakers discovered the particularly sweet taste of the grape juice, which was then processed into ice wine for the first time.
Manufacturing
The grapes are only harvested from the vines and processed in winter after sufficient freezing through, with persistent freezing temperatures below −7 ° C. This can be done up to and including January. At those low temperatures, the water separates from the fruit juice in the frozen grape.
During pressing, the separation of water and fruit juice means that a large part of the water remains in the grape as ice, and a small amount of highly concentrated juice is used to make ice wine. This explains why this predicate wine is so special and is only offered in very small quantities.
When pressing, it is important to note that the juice of frozen grapes can only be pressed out of the berries under high pressure. Particularly powerful "cloth presses" are therefore often used for ice wine vinification. With this type of press, however, care must be taken that the "loosening" of the mash takes place sufficiently during pressing and that the mash is prevented from freezing together.
Eiswein is usually developed "reductively", i.e. The young wine is protected as much as possible from oxidation during the aging process, which has a significant influence on the maturation and aroma of the wine and also has a positive effect on its color, smell and taste. When it comes to making ice wine, it is often all or nothing for the winemaker, because when playing poker with low temperatures, he often runs the risk of total loss, which is particularly likely in years with mild winter temperatures. In general, the rule of thumb is that only about 10% of the original starting quantity ends up as ice wine in the bottle. The rest of the grapes are either cut out selectively, remain in the wine press as ice or fall victim to the mild temperatures.
taste
As a rule, ice wine is made from white grapes, such as Riesling. Particularly experienced winemakers use Weißer Burgunder or Grüner Silvaner. The concentrated sweetness combined with a high degree of acidity is characteristic. That concentrated sweetness arises when the water contained in the berries crystallizes in persistent freezing temperatures below −7 ° C. This means that only the sugar contained in the berries binds non-crystallized water and fruit acids, which in turn leads to highly concentrated, sweet must, which is then fermented into highly concentrated, sweet wine.
Ice wines usually have a strong acidity, which forms a natural counterbalance to the intense natural sweetness of these wines. All of this makes ice wine, as an alternative to "normal" sweet wine, the ideal accompaniment to desserts.