Dessert wines are the hot-house flowers of the wine world. They are rare and difficult to make, which, of course, adds to their mystique as well as their cost. But there are some great bargains out there that are perfect with the dessert course, or can serve as desserts in and of themselves. Before we discuss the processes involved in making dessert wines let's review fermentation. In a nutshell fermentation is: sugar + yeast = alcohol + carbon dioxide. In other words as the yeast consumes the sugar, alcohol and carbon dioxide are produced as by-products. As more sugar is consumed, the alcohol level rises until it becomes toxic to the yeast. The yeast then dies and fermentation stops. So some wines have had all of the sugar consumed by the yeast so there is no residual sugar left. These are called dry wines. But others have plenty of sugar left in the final product. These sweet tasting wines are the so-called dessert wines. Port, Sherry and Sauternes are probably the world's most famous dessert wines, and interestingly enough they are each produced by different processes; fortification, solera and drying respectively.

Of these three processes, drying is the most ancient. Back in the heyday of the Roman Empire grapes were picked berry by berry, laid out on mats and allowed to shrivel and dry. Decreasing the water inside the grapes concentrates the sugars. Fermentation then proceeds normally, and stops when there is still plenty of sweetness in the resulting wine. Of the major producers of dessert wines Italy is the only one to still cling to this age old method. Vin Santo or "holy wine" is the delicious reward. But there is another very unusual method of producing dessert wines that is classified as drying. And the agent is a fungus called botrytis, or noble rot. This is the second oldest method of producing sweet wines. It is believed to have first ocurred during the harvest of 1650, when the Hungarians were unable, due to war, to pick the grapes. Rot began to attack the berries causing them to shrivel and dry. Remarkably, the winemakers plodded ahead and created the world's first botrytized wine called Tokay. This is also the method employed by the French in the Bordeaux region of France to make the incredible Sauternes. Believe it or not, but the noble rot adds the richness of honey and spices to both the Tokay and the Sauternes!

Soon after noble rot began sweetening the Hungarian wines, the Portuguese were experimenting with methods of preserving their dry red wines for the long trip to Britain. As alcohol is a natural preservative neutral spirits were added to the wine during fermentation. The addition of the alcohol killed the yeast and stopped the wine from fermenting further, leaving a lot of sugar left unconsumed. The two effects were a better, sweeter wine and a higher level of alcohol. True Port, or Porto, comes only from the Douro Valley in Portugal and has three quality levels; ruby - aged for 2-3 years, tawny - aged for 6 years in wooden casks before being bottled (both ruby and tawny are ready to be drunk when bottled) and finally vintage - which is only produced in the best years. It is aged for 2 years in wooden casks and then an additional 10 - 20 years of bottle aging are needed for the vintage port to mature. (If you have the bucks be on the look out for 1994 Vintage Port. Said to be the best since the hallowed 1945 vintage!) Other dessert wines also use the fortification method including Muscat de Beaumes-de-Venise from the Rhone Valley in France and Banyuls from the nearby province of Roussillon in France.

Strictly speaking Sherry is a fortified wine, but it undergoes an additional process that adds depth and finesse to the finished product. This process is fractional blending or solera. In the simplest terms, when you drink Sherry you are drinking history. A portion of the oldest cask is drawn off and used for bottling. That is replaced with wine from the next oldest barrel and so on until you reach the youngest cask which is topped off with wine from the present harvest. Every bottle of Sherry is a blend of all of the ages. Therefore there is no such thing as vintage Sherry. Since it is a blend of all of the vintages it is classified as NV or non-vintage. Of all of the dessert wines, perhaps Sherry is the best value. Good Sherry can still be found for ridiculously cheap prices! When shopping for this Spanish treat look for Sherries made from the Pedro Ximenez grape (or PX). They are wonderfully nutty and go well with most desserts.