Vidal Blanc

Vidal Blanc is a French hybrid, bred in the 1930s by crossing Ugni Blanc with a Seibel hybrid, and it has found its true calling several thousand kilometres from where it was created — in the frozen vineyards of Ontario, where it makes most of the world's icewine.

It is exceptionally well suited to that job, and the reasons are all physical rather than aromatic. Vidal has very thick skins and a tough, resilient berry that stays attached to the bunch and resists splitting and rot long after other varieties have dropped or rotted away. Icewine requires the fruit to hang on the vine until it freezes naturally — in Niagara that means waiting until at least minus eight degrees Celsius, often in December or January — and very few grapes survive that wait intact.

When the frozen bunches are pressed, the water in them stays behind as ice and only a trickle of intensely concentrated juice comes out. The resulting wine is thick, golden and enormously sweet, with apricot, mango, peach, honey and candied pineapple, held in balance by acidity that is equally concentrated. Without that acid it would be undrinkable.

Canada is the world's largest producer of icewine, and Vidal accounts for the bulk of it; Riesling icewine is rarer, finer and more expensive. Germany and Austria make Eiswein from vinifera varieties, and the two traditions are related but distinct.

As a dry wine Vidal is unremarkable, which is why almost nobody makes one.