Ice Wine

It's harvest time!

"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.

First, there are only a few spots in the world, where it gets cold enough to make ice wine. Canada and Germany of the most likely location, accounting for about 75% of the worldwide production.. But, not only does it have to get cold enough, the growers need a good growing season in the summer months. Ideally a hot summer, allowing the grapes to ripen and build their sugar levels. Next, they need a dry fall, avoiding rot. And finally, they need a cold, sharp winter with consistent temperatures below 15 degrees fahrenheit. Often times, this means harvesting in the dead of the night. All the while, the grapes remain on the vine, exposed to the elements, as well as birds and deer. It can be a real gamble as to whether or not the vintage will be successful.

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..

The grapes are then harvested, either by hand or machine, and transported to the containers, and ultimately the press. The pressing of grapes for regular wine is very gentle, but in the case of ice wine, the pressing is much more aggressive, squeezing at high pressure to extract what little juice is still available in the grape. Some times, this can be just a trickle of juice.

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.

In Canada and Germany the grapes must naturally freeze on the vine to be called ice wine. But, in some other countries, cryoextraction is done, to mechanically produce something similar to natural ice wines. These types of wines are sometimes referred to as "icebox wines".

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!
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