Port wine is a natural and fortified wine, produced exclusively from grapes from the Demarcated Region of the Douro, in the North of Portugal to about 100 km to the east of the city of the Port. São João da Pesqueira, Régua and Pinhão are the main production centers, but some of the best vineyards are in the area to the east.
Santa Marta de Penaguião is the county with the largest production of Port wine at national level.
Although produced with Douro grapes and stored in the cellars of Vila Nova de Gaia, this alcoholic beverage was known as "port wine" from the second half of the 17th century because it was exported to the whole world from this city. Vila Nova de Gaia is the place with the highest concentration of alcohol per square meter in the world.
The "discovery" of Port wine is controversial. One of the versions, defended by the producers of England, refers that the origin dates from century XVII, when the British merchants added brandy to the wine of the Douro region to avoid that it stilled. But the process that characterized its attainment might have been known well before the beginning of trade with the English. Already at the time of the Discoveries the wine was stored in this way to conserve a maximum of time during the trips. The fundamental difference lies in the area of production and the varieties used, now protected. Croft was among the first to export port wine, followed by other English and Scottish companies.
What makes Port wine different from other wines, besides the unique climate, is the fact that wine fermentation is not complete, being stopped at an initial stage (two or three days after beginning), by the addition of a brandy neutral wine (with about 77º alcohol). Thus Port wine is a naturally sweet wine (since the natural sugar of the grapes does not turn completely into alcohol) and stronger than the other wines (between 19 and 22 ° alcohol).
Three types of Port wines are fundamentally considered: White, Ruby and Tawny.