Making Icewine

[NorthernWiner]

Cryo-Extraction Process, Part 2

Now comes the part where we increase the sugar. Once the juice is frozen solid, remove the containers and let them sit out for several hours until the juice begins to thaw and is a bit slushy. Remove the caps (or just punch some holes in the bottom) and invert each container and set in a colander over a bucket. Note that you don't have to use as many containers as I did, but I find that the smaller containers make for quicker thawing.

From time to time you will want to collect the smaller buckets and empty them into your fermenter. Once you have enough juice in the fermenter, put a hydrometer in so you can monitor the Brix level. Remember, you want the juice to be between 32° and 40° Brix.

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[NorthernWiner]

Cryo-Extraction Process, Part 1

Cryo-Extraction

Icewine requires juice with a lot of sugar to start with. If you were to leave grapes on the vine into the winter, they would eventually freeze into hard, raisined little knots. The watery part of the grape freezes solid while the sugary pulp, with it's lower freezing point, remains liquid. The secret to Icewine is in capturing the sugar by pressing the grapes while frozen. It requires some heavy duty equipment. Your typical basket press just won't do the job.

For my Icewine, I purchased 23 liters of refrigerated Muscat grape juice from the Lodi region of central California. This juice started at 25° Brix(Brix is a measure of the percentage of sugar), but what I needed was more like 32° to 40° Brix. Icewine typically has alcohol in the 11-13% range, and residual sugar of 5-20%. It's sweet and alcoholic, not unlike the famous Sauternes dessert wines of France.

The first thing you need to do is freeze the juice. I divided the 23 liters into several plastic jugs (making sure to leave some room for expansion) and put them in the freezer for several weeks. I could've just waited a few days, but I wanted to wait and start this project in the middle of winter - not because I'm trying to be traditional - but because I can use the cold weather to my advantage. I'll explain in a bit.

Note that the juice I purchased already had sulfite added. If you use juice from fresh grapes, you may want to add 30-40 mg/liter sulfite before freezing. It will help protect from oxidation (yes, juice will still oxidize in the freezer).

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[NorthernWiner]

Note: I approached Bob several weeks back about writing up an Icewine tutorial. At the time, I didn't have many pics showing the progress. But now I do. - Steve

Overview

For those of you who have never had it, Icewine (Eiswein in Germany, Vin de Glace in France) is a real treat. More dessert than wine, it can contain up to 20% residual sugar - along with copious amounts of alcohol.

True Icewine is difficult and expensive to make. Producers in Canada and Germany must adhere to strict government regulations in order to call their product Icewine. Grapes must be harvested and crushed in the dead of winter, and requires equipment far out of reach for most home winemakers.

Fortunately, we can create a close approximation by skipping the frosty harvest and employing a technique called "cryo-extraction." While that sounds impressive and high-tech, it's really involves nothing more than freezing white grape juice and doing a partial thaw in order to concentrate the sugary goodness.

When making faux Icewine (or "icebox wine"), there are many white grape varietals that work nicely. What you want to look for is one that has an intense bouquet. Acidic varieties are also preferred, since acid will help balance the intense sugar and not leave the wine tasting syrupy and flat. In Germany, Riesling, or sometimes Gewürztraminer, is used. In Canada, a hybrid varietal called Vidal Blanc is the grape of choice.

For my own Icewine, I chose Muscat Canelli. Muscat has a great floral nose that smells reminiscent of tea roses and citrus.

In the following posts, I'll walk through the general process. I don't like to use the term "recipe," because it implies methods that must be strictly adhered to. In winemaking there are too many variables, and what works well for one person may not work for others.

Enjoy!

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