Dessert wines fall into four basic categories:
Late Harvest and Ice Wines
Late harvest wines refer to those wines produced from grapes picked toward the end of harvest when they are very ripe. These grapes are very high in sugar content. This high sugar content can make the late harvest wines very sweet, high in alcohol, or both. These wines are very rich and bold. These are typically served after the main course with fruit or cheeses.
Ice wines are made from frozen grapes. Because the water in the grape is frozen solid, when the grapes are crushed, the resultant juice is highly concentrated and high in sugar content. The wines are very sweet and often have a more full body flavor than late harvest wines.
Botrytised Wines
In Europe, these wines are the result of 'noble rot' which is a beneficial mold that grows on grapes under certain conditions. When properly cultivated, these grapes are concentrated in sugar and flavor. In California, botrytised wines are typically referred to as late harvest wines.
Vin Santo
An Italian dessert wine produced in certain parts of Tuscany from dried grapes. These wines can range from very sweet to quite dry.
Fortified Wines
Fortified wines are wines that have had distilled sprits add, such as brandy, to stop the fermentation and retain the sweetness and flavor of the grapes. These higher alcohol wines include Port, Marsala, Madeira, Sherry and Vermouth.