The home of Port—perhaps the world’s most popular after-dinner drink, the Douro region of Portugal is one of the world’s oldest delimited wine regions, established in 1756. Less well-known but often of excellent quality are the region’s dry table wines, both red and white. The vineyards of the Douro, set on the slopes surrounding the Douro river (known as the Duero in Spain), are among the steepest in the world, necessitating the use of terraces in much of the region. This often requires grapes to be harvested by hand—a labor-intensive process. The climate here is Mediterranean, with hot, dry summers and cold winters. There are three sub-regions of the Douro—Baixo Corgo, the mildest and wettest, Cima Corgo, where many of the best producers are situated, and Douro Superior, the hottest and driest. The best sites, typically with schist-based soils, are reserved for Port production, while table wines are usually grown on granite.

While more than 100 indigenous varieties are approved for wine production in the Douro, there are five primary grapes that make up most Port and table wines. Touriga Nacional is the finest of these, prized for its deep color, tannic and concentrated structure, and floral aromatics. Along with Touriga Nacional, Tinta Roriz (Spain's Tempranillo) helps to provide the backbone to these wine and adds bright acidity and red fruit flavors. Touriga Franca and Tinta Barroca help round out the blend with their soft, supple textures. Tinta Cão, a fine but low-yielding variety, is rarely planted but still highly valued for its ability to produce excellent, complex wines. Rosé Port and table wines are produced from the same varieties, while whites are generally crisp, mineral-driven blends of Arinto, Viosinho, Gouveio, Malvasia Fina, and an assortment of others.

With hundreds of red grape varieties to choose from, winemakers have the freedom to create a virtually endless assortment of blended wines. In many European regions, strict laws are in place determining the set of varieties that may be used, but in the New World experimentation is permitted and encouraged. Blending can be utilized to create complex wines with many different layers of flavors and aromas, or to create more balanced wines. For example, a variety that is soft and full-bodied may be combined with one that is lighter with naturally high acidity. Sometimes small amounts of a particular variety are added to boost color or aromatics. Blending can take place before or after fermentation, with the latter, more popular option giving more control to the winemaker over the final qualities of the wine.