Fortified Wines
These still wines have been “fortified” with a distilled spirit such as brandy. The original use of fortification was to preserve the wine, as casks of wine were prone to turn to vinegar during long sea voyages. The liquor is added to the base wine during fermentation. This fortifying of the wine brings the average alcohol content up to around 17 to 20 percent alcohol by volume.
The most common types of fortified wines are Madeira, Marsala, port, sherry, and vermouth.