Raising an icy glass

The recent cold snap has been exceptional, but imagine if you had to go out in the biting cold and pick grapes. Not the usual, juicy, ripe grapes but icy, bullet-like grapes, frozen on the vines and destined to be made into one of the world's most fabulous sweet wines – icewine.

This is what happens in Canada, where some of the world's best icewines are made. With good growing conditions for grapes during the summer and winters where temperatures regularly dip to –14 degrees, the Niagara Peninsula is becoming the icewine capital of the world.

Stretched out along the southern shores of Lake Ontario, a short distance from Niagara Falls, the peninsula is Canada's most important wine region, with more than 6,000 hectares of vines. Based around the beautiful, historic town of Niagara-on-the-Lake, with the US border across the river, this is a region bustling with tourists.

Canadian icewine is a sweet wine made from naturally frozen grapes. It is difficult and very expensive to make these wines but they capture the pure, concentrated flavours of the grape, exquisitely balanced against acidity and sweetness. They have a purity of style, with knife-edge precision and they accompany food tremendously well. But to make them you need to get out into the cold.

The science is very simple. Instead of being picked at normal harvest-time, grapes are left on the vines, often until January. The grapes dry out a little and they go through a few freeze-thaw cycles which makes the acids, sugars and flavours develop complexity and concentration. This is not the same as Sauternes, where a mould concentrates the berries.

Of course, in a snowy landscape those sweet bundles of grapes are a great attraction for the local wildlife, so the vineyards must be netted, but even that cannot guarantee to protect the crop. Clever birds wait until the snow gets high enough for them to perch on to reach the berries. When the temperature falls below –10C, ice crystals form inside the grapes, freezing them solid like bullets, although only the water is frozen, leaving all the sugars, acids and flavours trapped in the ice, like a natural sweet-and-sour slush. Sometimes the grapes fall off the vines at this point, which is another good reason to wrap the vines in nets. That is the time that the pickers go out. Collected in small boxes, the grapes are often pressed out in the vineyards, so that they don't melt on their way to the presshouse. It is vital that the juice is extracted quickly and gently so that the ice remains in the press and pure, concentrated, flavourful juice runs out to be made into wine. To make sure that no-one cheats, there are icewine police who have to be notified before the pickers go out and who can come and check if the temperature in the vineyard is cold enough.

Fermenting a juice which is sweet and syrupy is not easy and can sometimes take months. Some winemakers prefer to use oak, others stainless steel. In any case the quantities available are usually tiny. Each grape yields just one drop of juice, which accounts for the small-sized bottles and the very high prices.

There are three main grape varieties used in Niagara. Vidal is a local hybrid, valued for its winter-hardy thick skin and its aromatic apricot and mango fruit flavours. Riesling is gaining popularity and makes pure, clean wines with good acidity which counterpoint the sweetness of the wine to perfection. Cabernet Franc is a surprising choice for icewine but its lively raspberry and strawberry fruit aromas, coupled with a fresh, pink colour makes this a delightful wine.

I visited the region last summer. Now their daily average temperature is around –2C, but it should get colder in another week or so. These are some of my favourite icewine producers in Niagara.

Inniskillin – founders Donald Ziraldo and Karl Kaiser of Inniskillin were the pioneers of icewine here in the 1970s and the company still makes some exceptional wines. 2007 Riesling

icewine has delicious complexity with notes of lemon meringue, apricot and lime, with pure, gentle sweetness backed by zingy acidity. Find it at Drinks Direct (Bradford) 54.94 for a half bottle. www.drinksdirect.co.uk

Inniskillin Sparkling Icewine 2007, made from the Vidal grape, provides a light fizz which cuts through the sweetness and gives crisp apricot fruit and a rounded finish. Try this with a fresh fruit tart.

Peller Estates – based in a stylish winery, complete with a high-end restaurant, Peller Estate produce impressive wines, including a rich, crystallized-apricot and citrus-spiked Vidal Icewine 2008 which I enjoyed served with blue cheese. 29.95 a half bottle at Halifax Wine Company, www.halifaxwinecompany.com.

For a taste of raspberry-edged heaven try Peller Estates Cabernet Franc Icewine 2007 (39 a half bottle, Halifax Wine Co), which combines wonderfully with a chocolate and cherry desert. Hic Wines, based in Castleford also stock Peller Estate wines – www.hic-winemerchants.com.

Jackson-Triggs – another top-end winery making impressive wines. Try Vidal Icewine 2007 (14.48 for a quarter bottle, Drinks Direct) with lavender ice-cream and ginger biscuits.

Icewine doesn't have to be served with a dessert. I enjoyed it alongside dishes such as gorgonzola and fig salad, foie gras and grilled apricots or a ginger-spiced duck

and mango starter.

YP MAG 8/1/11