strong and/or sweet ...
It's fairly safe to say that most consumers consider table wines to be "dry" and dessert wines to be "sweet",
but this is gross over-simplification. Although dry and sweet are at opposite ends of the beverage alcohol flavor spectrum, there
is indeed a spectrum, with many gradations that are not purely one or the other.
Both the "table wine" and "dessert wine" categories include enormous diversity, further
complicated by wines that meet either or both the legal definition as well as the practical definitions, of table wine and dessert
The legal definition, at least for wines sold in the United States, is quite succinct. The TTB classifies any wine with over 14% alcohol
as "dessert wine"; wines with under 14% are in the "table wine" category. Since this agency definition is strictly
concerned with levying taxes, the somewhat arbitrary cut-off keeps it simple for the bureaucrats, but can confuse the public. Very sweet wines (high residual sugar) that are also low in alcohol are officially classified as table wine. Any wonder why the government credibility is lacking among the citizenry?
As a practical matter, many wines made since the late 21st century and produced from grapes allowed to reach high levels of ripeness,
sugar, and therefore alcohol, get taxed at the dessert wine level, although most of these wines are intended to be served as "table
wines". The level of alcohol content is an after-thought for most consumers, whose only consideration to classify any wine as dessert wine is a high level of
Consumers accept specifically sweet dessert wines as such no matter what alcohol level they contain, in spite of potential official classification as table wine. Some dry wines, that on the other hand would horrify most consumers if served for dessert, specifically gain entry into the
(legal) dessert wine category by virtue of their alcohol content.
Beyond this dry subject of politics and legalese, now consider only the sweetness of wines in the dessert context.
There are some classic styles of dessert wine that are appellation-specific and many proprietary dessert wines that emulate these
classics or are otherwise unique. Classic style dessert wines would at least include Moscato, Port, Sauternes, and (sweet styles of) Sherry, maybe along
with Asti Spumante, Ice Wine, Madiera, Marsala, Passito, Tokay (Tokaji), and other possibilities.
The production of these dessert wines involves acquiring or achieving a high level of sugar and then retaining or stabilizing this
sweetness in the finished product. There are several different methods, practices, or techniques used to accomplish these twin
The natural biochemical process of fermentation will continue, unless subverted, until the yeast consumes very nearly all of its
food source (sugar). One obvious way to retain some natural grape sweetness in finished wine is to prevent the yeast from fermenting it all into alcohol.
Yeast can be inhibited by adding sulfur above its tolerance. Fermentation can also be halted by lowering or raising the temperature beyond the metabolic limits of the yeast. For the sugars left in the wine to remain unfermented when the temperature returns, the yeast must be filtered out. This is called "sterile filtering".
If the sugar concentration in the grapes starts out to be so high that the resulting
alcohol exceeds 15%, the yeast will die off and any remaining sugar will remain unfermented. Sterile filtering is also recommended for stability.
Grapes are allowed to over ripen and reach high level concentrations of
sugar, assisted by dehydration (passerillage), by delaying harvest. Sauternes is made in this manner; semillon and sauvignon blanc, often assisted by
Botrytis, are allowed to reach high sugar concentration and some dessication.
German rieslings are so routinely made sweet by the same strategem, that they have graded their wine types by the harvest conditions: Spätlese (late picked), Auslese (selectively picked clusters), Beerenauslese (selectively picked individual berries), and Trockenbeerenauslese (individually picked shriveled berries). Fermentations may be halted by chilling or adding sulfur or both and the resulting wines, although sweet-tasting, will have alcohol content in the "table wine" (normally dry) range, from 7% to 14%.
Similar late harvest techniques are used to make dessert wines in the Loire Valley, particularly from chenin blanc, and in Alsace from several
varieties. Some dessert wines are also made this way from many different varieties in both Australia and in the United States.
Besides extended ripening, other means may be used to concentrate grape sugars. Grapes may be allowed to partially raisin, either before
or after being harvested. Sometimes grapes are forced to raisin before they are fully mature, to keep the acids high, the skins thick, and to increase resistance to rot.
Twisting or tying off the cluster stem causes raisining on the vine. Normally-ripened grapes can be harvested, then spread on reed mats or paper trays
to dry in the sun or the bunches tied along rafters. In either case, only clean and healthy fruit is used; during the drying stage it is important to keep air circulating between the bunches and to remove any berries that show signs of rot.
The length of time needed can vary from three weeks to four months, depending upon the grape variety, the type of wine being made, and the weather conditions at the drying location.
This partially dried fruit may be fermented on its own or added to base wine made from normally-harvested fruit. The technique, called passito, evolved in Greece and dates back to the 8th century B.C. or before. Surviving primarily in Italy, it is used, entirely or in part, for such wines as Amarone and Recioto (in Veneto), Vin Santo (in Tuscany), and many others throughout the country.
The public association of the term "fortified" with extra alcoholic kick prompted legislators to substitute the term "dessert" when they determined categories for taxing alcoholic beverages. Some dessert wines indeed get most of their alcohol by fortification, having distilled spirits added, rather than creating it naturally by fermentation. Not all fortified wines are sweet, however.
Grapes are allowed to begin fermentation; then distilled spirits are added to raise the level above yeast tolerance, stopping fermentation and retaining the remaining sugar. Port, Sherry, Marsala, and Madeira are all made by fortifying partially- or completely fermented must. Depending upon the region and style, the wines may then be further aged, blended, sweetened, or treated in some manner according to traditional practice that give that product its unique consumer appeal.
Compared to half a century ago, fortified wines have fallen out of favor with the public. As evidence of this change, total production of fortified wines in the USA in 1995 was less than 6% of what was produced in 1955.
1. Jancis Robinson (ed),
Oxford Companion to Wine, 3rd Edition, (Oxford University Press: London) 2006
2. Benjamin Lewin, Wine Myths and Reality, (Vendage Press: Dover, DE) 2010
3. Harvey Steiman,
Wine Spectator's: The Essentials Of Wine, (Wine Spectator Press: New York) 2000
4. Steven Spurrier & Michel Dovaz,
Academie du Vin, Complete Wine Course (G.P. Putnam & Sons, New York) 1983
5. Charles Sullivan,
A Companion to California Wine: An Encyclopedia of Wine and Winemaking from the Mission Period to the Present (University of California Press: Berkeley) 1998