"What?" you say. Yep, it is harvest time in Canada and Germany, where some of the best Ice Wine (or Eiswein) is produced. A year ago, I wrote about dessert wines, but only touched on the subject of Ice Wine. So, this week, in honor of the 2013 harvest, I thought we might take a look at how ice wine is produced.
So, why are cold temperatures so important? Well, the idea is to concentrate the sugars in the grapes. When they freeze, only the water freezes in the grapes, leaving a concentrated juice. The brix levels (one degree brix is equal to one gram of sucrose in 100 grams of juice) can reach in the 40's. Normal still wines, are harvested around 24 to 26 brix..
Since the pressed juice is so high in sugar, we need acid to balance the sugar, and for that reason, we typically see grapes grown with natural acidity: Riesling, Cabernet Franc, and, in Canada ,Vidal (a hybrid). Additionally, the high sugar levels mean that the yeasts involved in producing alcohol, will have a tough time. Fermentation can actually take months, and special strains of yeast are used. Even with the long fermentation, the juice will never fully convert to alcohol, so we are left with a high amount of residual sugar, making a medium to full bodied wine with a slightly lower alcohol level that regular wine.
So, now that the harvest is underway, we should start seeing this vintage on the shelf just in time for summer. But no need to wait that long, go out and find a bottle of last years vintage at your local wine shop. For my money, the best known producer in Ontario, Canada is Inniskillin. Look for it, and give it a try!