Eiswein, (Ice Wine), is rarity and a speciality. The grapes that produce this exceptional wine must be harvested at temperatures of -7°C or below. Such frosty conditions freeze the water content of the grape. This water remains in the wine press whilst the juice drips into vats, giving this wine its dense concentration of sweet grape extract. With such high sugar levels, it is difficult for the yeast to process the juice into wine. Eiswein, as a result, tends to have a very high natural sugar content that usually exceeds 100 grams per litre, yet it has low alcohol levels of around 7% volume - unlike sweet wines from warmer countries. Despite its large amount of residual sugar, Eiswein has a refreshing acidity.