Dessert Wines

LATE-HARVEST WINES 

Late-harvested grapes — some left for so long that they have begun to shrivel and turn to raisins on the vine — contain higher levels of sugar. During fermentation, the yeast dies when the alcohol level in the wine reaches 18-19 percent. Simply stated, then, with very sweet grapes, fermentation stops before all the sugar has been consumed, and the residual sugar results in a sweet wine. 

In the past, though initially delicious, many of these sweet wines would spoil rapidly or even re-ferment. Today, once a dessert wine is made, it is stabilized to enhance its enduring qualities. This process most often involves filtration to remove all remaining yeast, and the addition of very small amounts of sulfur to inhibit microbial activity. Consequently, today's dessert wines are clean, scrumptious, and often long-lived. Indeed, because sugar acts as a natural preservative, sweet wines have been known to age much longer than dry wines. 

LATE HARVEST: Some late-harvest grapes are simply allowed to dehydrate on the vine (or after harvesting), a process that concentrates their sugar and flavors. Desiccation, however, doesn't always preserve the grape's internal flavor balance, which can be overpowered by pure sweetness. Raisins, the ultimate product of grape dehydration, have lost their acidity and are fundamentally just fruit sugar. 

BOTRYTIS-AFFECTED: Another accidental discovery in the vineyard can produce exceptional balance in late-harvest wines: Botrytis cinerea, also known as “noble rot.” Botrytis is a mold that can occur in vineyards when warm and wet weather patterns alternate while the grapes are ripening. Botrytis mold settles on the grape skins and punctures small holes in them, allowing water to escape without affecting the fruit's flavors or inherent acidity. Though prized, Botrytis does not occur on all late-harvested grapes, which is why it's frequently mentioned on the labels of affected wines. (It is occasionally induced, as in the grapes that go into Beringer's Nightingale dessert wine.) You'll always recognize Botrytis, even if the wine is not labeled as such, by its distinct honey character, layered over other complex fruit nuances. 

EISWEIN: From the world of late-harvest wines comes one other special style: Eiswein, or ice wine. Again, it's a creation of pure happenstance: grapes left out on the vine during a late harvest in Germany succumbed to frost. The grapes were rushed back to the winery to crush immediately, whereupon it was found that the water (in the form of ice crystals) could be removed, and the sticky-sweet essence of the grape allowed to ooze into a barrel (or, later, a tank). This liquid, when very slowly fermented, produced the amazing nectar Eiswein. This style of wine (which is often Botrytis-affected) is produced in the coolest of cool climates. Or it can be replicated by simply freezing (yes, in a freezer) late harvested grapes and crushing them… really, but not legally, as far as labeling as Eiswein or Ice Wine is concerned!

SPARKLING WINES

For most traditional styles of sparkling wine and champagne, of course, the level of dosage (extra dry, demi-sec, or doux); is critical, as the style classifications are based on total sugar content by volume. If you prefer your dessert bubbly sweeter, opt for a demi-sec. If you like a somewhat drier option, an extra-dry will suffice. In bubblies, those made from a sweet still wine, such as Piedmont’s Asti, the level of sweetness is determined by the final blend of the cuvée. Some dessert wines are made with less effervescence; these range from crémant-style wines produced in the United States to those akin to Moscato d'Asti, which is less fizzy and sweet than classic Asti. 

FORTIFIED WINES

PORT STYLES:  With port, the quality of the fruit usually determines whether the wine will be vintage, in which case much of the aging will take place in the bottle. If not, it will spend more time in wood and be blended before bottling. 

The same is true for this genre of wines in California, whether using classic port grape varieties, Zinfandel, or even a Petite Sirah now and then. The age of the blend will often determine the wine's character and how it is classified. The older the base blend, the less overt the primary fruit flavor and the greater the influence of oak, dried-fruit and herbal flavors. Longer barrel aging softens the tannins in port-style wines, both leeching color and adding texture. The degree of fortification will vary from producer to producer, but the higher the level of alcohol added, the longer it takes for the spirit to integrate into the wine so that it doesn't come across as hot in the mouth. If you have ever sampled a young fortified wine that tastes very alcoholic and burns your mouth, it has most likely been heavily fortified. The choice of wood is almost always oak, though, as with other wines, both the age and size of the barrels are crucial. Most port-style wines are aged in larger and older oak (or chestnut) casks, except for vintage ports, for which some new oak is often used. For sherry, winemakers prefer older American oak barrels, often previously used (and thus seasoned) by Scotch or bourbon distilleries.

Though seldom produced in California, dessert wine styles of this type are made in the Golden State: 

• Like port some time ago (shipped from Portugal to England and initially created “by accident”), Spanish wines from Jerez (sherries) were also fortified and shipped in casks, but, as the wines were always fermented dry, to the point of containing no residual sugar, no problems were encountered. Then someone decided to add “color wine” and “sweet wine” to this already fortified elixir to make it suitable for drinking with desserts. Cream sherries, brown sherries, and sweeter olorosos belong in this category.
• Madeira came into existence by being "cooked” in its casks as ships passed through the equatorial heat on their way to Asia and North America. California examples include Paul Masson and V. Sattui.
• In Italy, we find several styles of fortified wines, led by Marsala. For most, Marsala connotes the cheap stuff used to deglaze the pan to make a sauce for veal scaloppine, but the best Marsalas are sublime and range, like sherry or madeira, from dry (secco) to very sweet. You may find bottles labeled vino licoroso, which contain a sweet fortified style of wine. 
• A lighter style of fortified wine is VDN (vin doux naturel in French), in which neutral spirit or brandy is added to the grape must during the fermentation to retain sweetness while bringing the final wine up to a moderate 14 percent alcohol. As the name suggests, many great VDNs come from France, and they can be made from various grapes: Muscat (as in the Rhône's Beaumes de Venise, Roussillon's Muscat de Lunel, and Frontignan) and Grenache (as in Banyuls and Rasteau). In Spain, a VDN Muscat is made in Sitges, and in Portugal we find a great VDN Muscat from Setúbal. All are laced with flavors of raisin, candied tangerine, and exotic spice.