The Douro Valley is a different climate zone from the rest of Portugal and is the place where the Portugal Port wine is created. In 1756 the region where Port wine could be produced was designated by the association that regulates its designation, quantity and production in any given year even today. The wine gets its name from the town where the Douro river leads to the sea, Porto.
The Douro valley is beautiful, the vineyards cover the steep hills, with olive trees marking the borders. Almonds are also produced in the region. We visited a working vineyard, designated for Port wine production. To produce Port wine the fermentation process is stopped by adding a neutral grape spirit known as aguardente, sometimes referred to as a brandy which stops the fermentation process, preserving the natural sugar in the grapes. The wine is then stored in wooden barrels and aged. The Port Wine Association determines how much Port wine can be produced in any given year and designates which years are special or vintage.
They were harvesting the grapes when we visited. The same grapes can be used for table wine we were told. For our tour group the highlight of this visit was stomping the grapes. Here is the video. After stomping grapes we had a lunch with of course, Port wine. This vineyard had been in the family for generations with the hiccup,1974-76 after the Carnation Revolution.