Today fortified wines are produced in one of two ways. The first method involves the addition of alcohol (typically grape brandy which is distilled, not fermented) during a wine's fermentation process. When added during fermentation, the alcohol will kill the remaining yeast before it gets a chance to consume all the natural sugar in the grape juice. With the residual sugar in the grape juice, this results in a fortified wine that is sweet. The second method has the additional alcohol added after the wine is fermented, producing a dry fortified wine. One way or the other, fortified wines end up being 15-20% alcohol by volume (ABV).
Port - From Portugal, this is a sweet fortified wine. The name was originally derived from the Portuguese city of Oporto where wines were shipped. Styles of port include:
Tawney Port: Aged 2 to 40+ years
Ruby Port: Aged 2 to 3 years then bottled. Meant to be enjoyed young
Late-Bottled Vintage (LBV) port: Single vintage bottled after 4 to 6 years
Vintage Port: The highest quality single vintage port that is wood aged for 2 years
Sherry - From Spain's Andalucía region. Two basic styles of Sherry:
Fino: Light and dry with alcohol levels of 15-16%
Oloroso: Oxidation makes this style deep brown in color, with higher alcohol levels (18-20%). Often sweetened and colored for variation. Also available as a cream Sherry
Marsala - From Sicily, this wine can be sweet or dry. It is produced through repeated heating and oxidation cycles. Although Marsala is most often thought of as a cooking wine, the higher quality Marsala wines are meant to be enjoyed as a fine wine. Quality levels include:
Fine: Aged for 1 year. Typically a cooking wine
Superior: Aged for 2 years
Superior Reserve: Aged for 4 years
Virgin (or Solera): Aged for 5+ years
Virgin Stravecchio Reserve: Aged for 10+ years
Madeira - From the island of Madeira, this can be dry or sweet, blended or single varietal. Like Marsala, this wine is repeatedly heated during production. Two main types:
Blended:
Reserve: Aged 5+ years
Special Reserve: Aged 10+ years
Extra Reserve: Aged 15+ years
Single Varietal:
Colheita: Aged 5+ years
Frasqueira: Aged 20+ years
Vermouth - Made from white wine that is then infused with herbs, fruits, and spices. There is no official, legal definition of vermouth, and no regulation controlling which grapes are used in its production. Vermouth can be dry or sweet. A typical sweet vermouth contains somewhere between 10-15% sugar that is added during the production process. Dry versions, which are lighter bodied, usually have less than 5% sugar.