Since the Central Washington and Southern British Columbia climates are somewhat unique in the world we are still learning about the best ways to utilize this arid environment. One such way has more or less been pioneered by British Columbia - ice wines and late harvest wines. B.C. winemakers have made a bit of a name for themselves with these wines, entering competitions and earning gold medals all over the world.
It did not take too long for B.C.'s Washington cousins to realize that we too can do the same thing. Our dry climate allows us to leave grapes on the vine long after optimum maturity has been reached. This allows the grapes to either freeze on the vine (ice wine) or slowly raisin and concentrate sugar (late harvest).
Long before the new world was discovered, and along with it sugar cane, the only source of sugar was honey or concentrating fruit juices. Thus I suspect that in the ancient worlds of western civilization sweet foods were prized above all others and sweet wines would have been considered the greatest of wines. To this day there are sweet wines made around the rim of the Mediterranean Sea in styles that have been traditional for centuries.
In northern European climates sweet wine would have been no less prized. However the length of the growing season is not long enough to develop high sugars. One way to do achieve elevated sugar concentration is to leave the grapes on the vine as winter approaches and hope they will freeze before they rot. If the grapes are picked and pressed before defrosting the ice crystals will remain in the press, thus concentrating the sugar. In a wet climate such as Germany's this can be very risky and expensive as it is more than possible the rot will occur before the freeze.
In the southeast of France in the Sauterne region they have a maritime climate where freezing temperatures rarely occur. There they leave the grapes and a mold can grow on them, known as noble rot, which removes water from the grapes, once again concentrating the sugars. This is also very risky because if the fall is too wet the noble rot can quickly become nasty rot.
That brings us to our arid climate which is an ideal environment for late harvest and ice wines. Blocks of vines can be left unpicked into late October and early November in the hopes that they will freeze and make ice wine. If however they do not freeze the odds are excellent that they will not mold, but dehydrate thus developing interesting and complex flavor profiles. Picking dates as late as December or even early January (which year do you put on the label?) are not uncommon for late harvest wines. Traditionally varieties such as Riesling, Gewurztraminer, and Sauvignon Blanc are used in these wines. However I have seen Late Harvest Pinot Noir made by Washington state wineries and obviously any grape can be made into a Late Harvest or Ice Wine.
In Washington these wines are often drunk with dessert and they can accompany many desserts to perfection. However in other areas of the world they are chilled and served as an aperitif before dinner, thus preparing the tongue for the stronger flavors to come. Also keep in mind that sugar is a preservative, helping these wines to age well. Sauternes have aged and drunk well two centuries after their vintage date.