Ice wine dates back to 1794 when it was accidentally discovered. A cool summer and an exceptionally cold winter hit Franconia Germany this year. Winemakers pressed juice from the frozen grapes out of necessity and ended up with a product with a surprisingly sweet flavor due to a high sugar concentration. It wasn’t until the mid 19th century however that ice wine was intentionally made.
Grapes are left on the vine after they have ripened and well into the winter months. The harvest commences when the temperature drops below -10 to -13 degrees Celsius. The berries are picked in the middle of the night and early morning and are pressed at a temperature that doesn’t exceed -8 degrees Celsius. As they are pressed the water in the grapes remain ice crystals, while the small remainder of the highly concentrated juice is extracted. In the case that the freeze doesn’t come quickly enough after the grapes have ripened, they may be at risk of being eaten by wild animals, drop off the vine, or rot, causing a possible loss of the entire crop. On the other hand, if the freeze is too severe, the entire grape will freeze, become to hard, making it impossible to extract juice.
In Germany, Austria and Canada, there are regulations that govern the production of ice wine and to be titled as such, they may at no point be artificially frozen or refrigerated. There are two exceptions to this; the tank cooling during fermentation and the cold stabilization prior to bottling. Referred to as “icebox wine”, winemakers may use cryoextraction, a mechanical freezing that simulates frost, after the grapes have ripened, to mimic ice wines.
The juice extracted from ice wine grapes amount to about 1/5th of the amount you would get from unfrozen grapes. After the pressing, the juice must achieve a minimum of 35 degrees Brix . Brix is a measure of sugar content in a liquid. One degree Brix amounts to one gram of sugar in 100 grams of solution and is often represented as a percentage by weight. The finished ice wine must be measured at a minimum of 35 degrees Brix.
Ice wine should be chilled for an hour or so and served at 5-7 degrees Celsius in 2oz. pours. When looking to pair an ice wine with food, be careful not to pair it with anything sweeter than itself. Try nuts or even tropical and mild fruits like apple and pears. Since ice wine is considered a dessert in itself, it is often preferred to be savored alone!