To make Icewine, the grapes are left on the vine until after the first frost hits. These grapes are harvested after being frozen in the vineyard and then, while still frozen, they are pressed. They must be picked early - before 10 a.m. During both of these processes the temperature cannot exceed -8 degrees C. At this temperature (-8 degrees C) the berries will freeze as hard as marbles. While the grape is still in its frozen state, it is pressed and the water is driven out as shards of ice. This leaves a highly concentrated juice, very high in acids, sugars and aromatics.