Origin and Styles
The original reason for fortifying wine was to preserve it. Alcohol is a natural preservative, and when added before the fermentation of wine is complete, it kills the yeast and leaves residual sugar behind. The end result is a wine that is both sweeter and stronger, normally containing about 20% alcohol by volume (ABV). Even though other preservation methods exist, fortification continues to be used because wine drinkers took a liking to this kind of wine.
Although grape brandy is most commonly added to produce fortified wines, the additional alcohol may also be neutral spirit that has been distilled from grapes, grain, sugar beets, or sugarcane. Regional appellation laws dictate the types of spirit that are permitted for fortification.
The source of the additional alcohol and the method of its distillation can affect the flavor of the fortified wine. If neutral spirit is used, it will usually have been produced with a continuous still, rather than a pot still.
During the fermentation process, yeast cells must continue to convert sugar into alcohol until the must reaches an alcohol level of 16%–18%. At this level, the alcohol becomes toxic to the yeast and kills it. If fermentation is allowed to run to completion, the resulting wine will (in most cases) be low in sugar and will be considered a dry wine. The earlier in the fermentation process that alcohol is added, the sweeter the resulting wine will be. For drier fortified wine styles, such as sherry, the alcohol is added after the end of fermentation or soon before the end.
In the case of some fortified wine styles (such as late harvest and botrytized wines), a naturally high level of sugar will inhibit the yeast. This causes fermentation to stop before the wine can become dry.
By law, the term “fortified wine” is not permitted to appear on wine labels in the United States; consequently, these wines are usually called dessert wines.In Europe, they are called liqueur wines. Under European Union legislation, a liqueur wine is a fortified wine that contains not less than 17.5% ABV (except for certain quality liqueur wines) and that meets many additional criteria.
- ^ a b Lichine, Alexis. Alexis Lichine’s New Encyclopedia of Wines & Spirits, 5th edition (New York: Alfred A. Knopf, 1987), 236.
- ^ a b c Robinson, J. (editor). The Oxford Companion to Wine, 3rd edition (Oxford University Press: 2006), 279, ISBN 0198609906.
- ^ COUNCIL REGULATION (EC) No 1493/1999 of 17 May 1999; Annex I, §14 (European Union document). See page 40.