Ice Wine, cool and fine!
Modern ice wine production started in Germany in the late 18th century when a harsh winter froze the grapes on the vine. The producers were forced to pick and press while the water inside the grapes was frozen. It is possible that ice wine was being made long before this and there are some literary indications that suggest it was used even in the Roman times.
How is ice wine made?
There are now two main methods of producing ice wine. Natural and Cryoextraction.
The first is the traditional method of freezing the grapes on the vine. This is an incredibly risky process as the conditions will not be right every year. The grapes must remain on the vine past the typical harvest dates (between September and October) and not be affected by rot or disease. The weather conditions must get to at least -7/-8°C until the grapes freeze. They are then picked and pressed before the grapes defrost. The frozen water remains solid and only the unfrozen sugary juice is released. This means that only a small amount of liquid is released resulting in a very low yield.
One the juice has been collected the fermentation can start. The very high sugar levels mean the yeasts will naturally stop fermenting before the wine reaches dryness, therefore ice wines are always sweet.
The other alternative is cryoextraction. This is the ‘man-made’ method using freezers to replicate natural conditions. The grapes are picked at typical harvest times and then frozen. They can then be pressed and fermented as the traditional method but this will start earlier.
The grape varieties
The most common grapes varieties used for ice wine are Riesling, Gewürztraminer, Chenin Blanc, Grüner Veltliner, Cabernet France and Vidal Blanc. The grapes are cool climate varieties that can thrive and survive in these conditions.
Riesling is a fantastic variety considered a noble grape in Germany. It has very hard wood meaning it doesn’t die in the cold conditions. The grapes flavours in ice wine can range from crisp lime to tropical pineapple and mango. Riesling is grown in all of the main ice wine regions including Canada and Germany. The grapes natural high acidity cuts through the sweetness creating a fresh sweet wine.
Gewürztraminer is a mispronounced and misunderstood grape variety. However, once you have tasted this grape you will have trouble forgetting it. Big, bold and fruity with strong flavours of apricot and grapefruit. Gewürztraminer also has wonderful spicy and floral aromas of allspice and rose. Ice wines made from Gewürztraminer always have a lovely honey taste with high levels of sugar.
This is a great variety for ice wine production as it is full of fruit flavours and high acidity. Many of the ice wines made from Chenin Blanc are frozen through cryoextraction.
The main grape variety used for Austrian ice wine is Grüner Veltliner. It has
Cabernet Franc is the only red grape variety that is commonly used for ice wine production. This grape is mainly grown in Canada, particularly the Niagara Peninsula. It gives lovely red berry, currant and pomegranate flavours
Vidal Blanc, this is a more unusual variety and one most people will not have heard of. It is more commonly just referred to as ‘Vidal’. It is a hybrid grape variety. Ugni Blanc is the Vitis vinifera parent and the other is another hybrid called Seibel 4986.
Vidal is extremely hardy with strong wood meaning it can survive in very cold conditions. It produces a lot of sugar with equally high acidity making it perfect for sweet wine production.
Pineapple, grapefruit and apricot are common fruit flavours in this variety with strong honey notes in ice wine.
Hybrid varieties are rarely grown in Europe because of strict rules therefore, Vidal Blanc is more commonly seen in the USA and Canada. Canada has the largest plantings particularly in the region of Ontario, especially in the more famous Niagara Peninsula. In America, the New York State produces some excellent ice wines.
The key countries for ice wine production are Canada and Germany. In Germany, it is called Eiswein. Canada is the worlds largest ice wine producer. The main reason for this is the Niagara Peninsula where a winter freeze is almost guaranteed. China is an emerging and exciting country that uses cryoextraction to produce its ice wine.
The taste of Ice Wine
Ice wine, unlike many sweet wines, is focused on highlighting the purity of the grapes’ natural flavour. The grapes for ice wine should not be affected by any form of rot, including botrytis cinerea (noble rot). Therefore, ice wine should reflect the grapes natural flavours.