Port wine (also known as Vinho do Porto, Oporto, Porto, or simply Port) is a sweet Portuguese fortified wine from the Douro Valley in the northern provinces of Portugal. It is often served as a dessert wine. Several imitations of Port are produced around the world in several countries—most notably Australia, South Africa, India and the United States. However, under European Union guidelines (and in Canada), only the product from Portugal may be labeled as Port. In a similar vein, Federal law in the United States mandates that the Portuguese-made product be labeled Porto or Vinho do Porto.
Port wine is typically richer, sweeter, heavier, and possesses a higher alcohol content than most other wines. This is caused by the addition of distilled grape spirits (aguardente similar to brandy) to fortify the wine and halt fermentation before all the sugar is converted to alcohol.
It is commonly served after meals as a dessert wine, often with cheese. White and tawny ports are often served as an apéritif. It has an alcohol content of roughly 20%.
Wine with less than 16% ethanol cannot protect itself against spoilage if exposed to air; with an alcohol content of 18% or higher, port wine can safely be stored in wooden casks that 'breathe', thereby permitting the fine aging of port wine.
Styles
Port from Portugal comes in several styles, which can be divided into two broad categories:
- 1. Wines that have matured in sealed tanks or bottles, with no exposure to air, and experience what is known as "reductive" aging. The wines very slowly take on a tawny colour, and become smoother on the palate and less tannic.
- 2. Wines that have matured in wooden barrels, whose permeability allows a small amount of exposure to oxygen, and experience what is known as "oxidative" aging. They too lose colour, but at a faster pace. They also lose volume to evaporation, leaving behind a wine that is slightly more viscous and intense.
When white ports are matured for long periods, the colour darkens, eventually reaching a point where it can be hard to discern (from appearance alone) whether the original wine was red or white.
Wines matured in barrels are sometimes known as 'wood ports'.