Ice wine, liquid gold and the biggest gamble in wine

Winemaking is known to be an expensive game of chance. No matter how much control we can develop in the winery, we are still at the mercy of weather. Among the things that we cannot control are how fast the fruit will ripen, how much precipitation, and how cold or hot the air temperature outside will be. This final variable of temperature is the name of the ice wine game.

It is truly a gamble, because you leave your beautiful crop out to the elements in the vain hope that it might get better. So there it sits for months, it was ripe and could have been picked to make a fine wine on its own, but now we have decided to see how much abuse it can survive and avoid, should the weather comply.

Michigan Weather Makes it Happen

Going into the fall in northern Michigan is a roller coaster ride of weather events. Being at the 45th parallel, we are in the midst of an annual, and ancient conflict. This is a series of battles between the cold air of the North Pole, and the warm air of the tropics. All summer long the warm tropical air dominates the landscape giving us the moderate and beautiful weather that allows us to make such delicate wines. But when the earth begins to tilt away from the sun the struggle begins. The cold northern air begins to dip down southward. Where this cold air meets the warm tropical air is the frontlines of the conflict, out of this clash arises the very changeable weather patterns, of sun, snow, rain, wind, and clouds. This is the hardest part of the year for ice wine. In addition to the weather, the berries must escape the birds who are migrating long distances and working up a great hunger. These birds can clean out entire vineyards in several hours, or while you are asleep.

As it sits patiently on the vine waiting for the perfect conditions, it must endure months of this erratic weather; sometimes it is January before it gets cold enough! That is a lot of extra time as most of the other grapes are picked by October.

What we wait for is the hard freeze, not the first frost, nor the overnight lows, but the solid ice. Berries freeze at a lower temperature than water (less than 32 degrees F) because they have sugars and other solids in them. So when you are picking ice wine you generally want the temperature to be around 15-17 degrees F for at least a day. This low temperature will freeze most of the water in the berry. Once the water is frozen and the grapes are pressed, a concentrated juice comes out. This is because the water stays behind as ice. This is the irony, as there is no ice in ice wine, in fact it is what is left out that gives it its name. All of this is just an elaborate system to remove water, and increase concentration of flavors.

Once the grapes are pressed the juice that comes out should be at least 35 degrees Brix, or roughly 35% sugar. Normal wine is pressed at about 22% sugar, for comparison. What this creates is a product that can only ferment part of the sugar, so there is quite a lot remaining in the final product, a rough minimum of 8%.

2007 Ice Wine

This year at Chateau Chantal, we had to wait a little longer than most of our neighbors to get the perfect conditions to harvest our fruit. Our grapes for ice wine are planted on a big hill, which the winery is on the top of. This big hill is the highest point on the Old Mission Peninsula. What this means is that the grapes will freeze at different times depending on placement on the hill, as cold air sinks and warm rises. Not to mention the excellent vintage year, which saw uniformly high levels of ripeness across the board, resulting in more sugar accumulation than normal. The last factor that contributes to the differences are the several varieties that we use for the ice wine. The majority is Riesling, as well as several other varieties used for the proprietary blend to enhance the bouquet.

These factors in turn necessitate lower temperatures to freeze the grapes. To get them uniformly frozen the normal 2 days at 17 degrees F, was not working this year. When we finally picked on Saturday December 15th, 2007 the overnight low was about 12.6 degrees F. Picking started at 7:00am while it was still dark by this time the temperature had risen to 14.6 degrees F. It was a calm morning with little to no wind. By 8:30 the grapes were picked and in the press.

Initial sugar concentrations were around 50 degrees Brix, and as they warmed slightly the concentration averaged about 44 Brix all day. Because the grapes are frozen the press began to ice over on the outside, and the juice trickled out all night long. They pressed for over 36 hours, a marathon session near the press. In the end the final sugar was about 40% sugar.

As you can see the making of ice wine is not for the faint of heart. It is a huge gamble to even get enough fruit off the vines in a timely manner, let alone the long press times and possible troublesome fermentations that are somewhat common with such high sugar levels, yeasts have a hard time living in such a high concentration of sugar. For all of these reasons ice wine is a very special product, it is rare, requires a lot of labor to make, and is made only when nature complies. And if it does, it creates one of the most sublime wines out there, enjoyable even for the novice as well as the seasoned aficionado. Its approachable for many that do not like dry wines, as there are no harsh tannins, as well for the well heeled for its many layers of complexity.

Because Ice wine is so special and complex I urge you to take your time when drinking it. This takes special attention as it goes down very smooth.

Tasting Ice Wine

Very often ice wine is served cold, directly out of the refrigerator, do not be afraid to let it warm slightly, using your hands to cup the glass as you swirl it. Gentle warming will allow all of the flavors to open up. Also a cold wine will hide its nuances or even some flaws.

Swirling mixes air into the wine, which volatilizes the aromas, so that you can smell them. Get your nose right into the glass to get the most bouquet.

Now once it is in your mouth, it will make you salivate, swirl it around and let it mix. This is because this wine is very dense, and letting it warm and dilute in your mouth will allow some of the flavors to come out.

Once you swallow it breath out of your nose. This will give you one last rush of flavor. Remember, most of what we consider to be flavor or taste, is actually smell.

Ice Wine as we say here at Chateau Chantal, is liquid poetry.

Filed under A Day in the Life • Wineries