Unlike sugary blush wines, dessert wines are naturally sweet, made with grapes that "raisinate" (when grapes shrivel and sugars become concentrated) before fermentation. The flavor is intense, sometimes overwhelming, and reminiscent of sucking a sugar cube. The high sugar content, like port, also enables enjoyment for up to a year after opening.
There are four major types of dessert wines, each reaching their sweetness in a different fashion: late harvest, "botrytized" wines, vin santo, and ice wines. Late harvest wines are currently popular with "new world" winemakers (US, Australia, South America). Not as sweet as the others, late harvest grapes stay on the vine after the harvest is finished, gaining a sweeter, more concentrated flavor over their picked brethren. The resultant wine tastes more sugary than normal table wines, but is quite refreshing. Several grapes amenable to late harvest (and other methods) are Zinfandel, Muscat (an aromatic grape usually reserved for dessert wines), Sauvignon Blanc, Riesling, Gewurztraminer, and Chenin Blanc. Every grape exhibits a different personality, so approach each dessert wine variety with an open palate.
Botrytis cinerea (a.k.a. "noble rot") is a fungus that attacks grapes during harvest when the weather conditions are warm and humid. Noble rot causes the fruit to shrivel and dehydrate, so when the grapes are harvested and crushed, the juice is intense with sweetness. Germany and France are experts at this method. Sauternes, a wine region in Bordeaux, France, produces primarily dessert wines and uses Semillon grapes. The Germans use Riesling, and call their botrytized wine "Trockenbeerenauslese."
Italian Vin Santo comes from just ripe grapes, cut off the vine and allowed to air dry to concentrate their sugars. This method creates some kick-ass alcohol content, reaching as high as 17 percent alcohol (most table wines fall between 10-15 percent). A variation of this method is also used to produce Vin de Paille, an ancient dessert wine experiencing resurgence right now in Europe.
The last method, and probably the least recognized, is Vin de Glaciere, Ice Wine or Eiswein, all different names for the same method of freezing the grapes on the vine (or after picking) in order to concentrate sugars. It produces a wine that is very sweet, but balanced and not overwhelming. The grapes used are normally Muscat, Semillon or Riesling.
White varietal dessert wines Semillon, Riesling, Sauvignon Blanc, Vin Santo are best enjoyed well chilled at 57-60 degrees Fahrenheit. Red varietals Zinfandel, Black Muscat should be slightly chilled to 65-70 degrees Fahrenheit. Often they are sold in half bottles (375 milliliters), because the rich, almost syrupy contents should be sipped, not slammed.
Librandi "Le Passule" Vino Passito 1997
Luscious almond and honey flavors dance all over this sweet white. Also has some citrus appeal. Made in the Vin Santo air-dried system. $26 (500 ml)
DeBortoli "Noble One" Botrytis Semillon 1997
Great stuff! Check out the pear flavor and aroma. Finishes clean and refreshing. Gonna be tough to find, but worth the effort. $25 (375ml) 1/2
Bonny Doon Vin de Glaciere Muscat 1999
Yet another fab wine from Bonny Doon. Intense, elegant, and a bit citrusy. This is a good one for drinking all by its lonesome. $16 1/2
Santa Julia Vineyards 2000 Tardio
Best of show! This unexpected pleasure comes from Argentina and their grape Torrontes. The wine is light and smacks of sparkling apple cider. Beautifully balanced and perfect with any fruit-based dessert. $14 (375ml) 1/2
Quady Elysium Black Muscat 1997
Sniff this one and you've got a face full of Smucker's raspberry jam. Incredible with anything chocolate. $13