Only after the British discovered port wine at the end of the 17th century did the fame of its fine quality start spreading all over the world. The Douro Valley region produces the grapes that give rise to the only authentic “Porto”. In the middle 1750s, the Portuguese authorities started controlling all the aspects of port wine production, including the demarcation of the boundaries of the Douro region.
Most of the port wines are blended and aged in a large number of the wineries in Vila Nova de Gaia, a town located across the Douro river from Porto city, with some featuring English names, attesting to the British origins of their founders. One of these founders, Joseph Forrester, obtained the title of baron in 1855 for his efforts at modernizing the port trade. Croft was one of the first big shippers, followed by other English and Scottish firms, and much of the port trade is still in British control. The more well-known names include Graham, Cockburn, Warre, Taylor, Krohn, Niepoort, Dow and Churchill. Some of the Portuguese traditional wine estates, called quintas, are Ferreira and Quinta do Infantado.
The origins of modern-day Porto date back to 1820, when that particular harvest yielded a very sweet and rich wine. The reasons for its original sweetness lay in the exceptional ripeness of that vintage, which naturally allowed some of the grape sugars to remain. This rich and fortified Porto is now obtained by adding 20 percent brandy (aguardente) to the liquid volume to arrest fermentation, and to maintain about 10 percent of the residual sugar. Fermentation of the grapes occurs in large stainless steel tanks, and after fermentation is stopped the mixture is allowed to settle for a few months in large oak vats. The juice is then moved into 115-gallon oak casks (pipas) where it matures.
Presently, the Porto Wine Institute and the Casa do Douro oversee its production and guarantee quality control.
What gives Porto its unique quality, aroma and flavor are the original combination of soil, climate and grapes found in Portugal’s Upper Douro River Valley, which stretches 62 miles to the Spanish border. There are five main grape varieties known for their superb quality—Touriga Nacional, Tinta Roriz, Tinta Barroca, Tinto Cao and Touriga Francesa—and they grow in a predominantly schistous, rocky and acidic soil. The vine roots grow very deep down through the fissures in the schist to find water in natural reservoirs. These vines grow in terraces along the steep riverbanks, and their grapes are harvested annually between September 15 and October 15.
All ports, aside from vintage, are matured in oak casks. Once bottled, they are ready for drinking and, unless unfiltered, do not require decanting. The tawnies are lighter in taste and color than the rubies, but they are all blended from several wines.
This port wine is less sweet and lighter than ruby or vintage ports. It is blended from wines of different years, usually no more than three years old. The lighter tawnies have been blended with white port.
This famous port wine pales to an amber color as it ages. Its aroma and flavor characteristics are the craft of a master blender, the person who creates the uniqueness of each of these wines. Aged tawny port may be labeled as 10, 20 or 30 years old, referring to the average age of its blend of old and young wines.
Vintage port wine is characterized by its intense red color, full body and complexity of flavor. In years of outstanding harvest quality, the producer must declare their best wine as “vintage,” and submit a sample bottle to be approved by the Porto Wine Institute after January of the second year from the harvest. The norm is to leave the wine in the cask for two to three years, and then age it in bottles where the best ones continue to improve indefinitely.
LBV port wine is less rich and concentrated than Vintage Porto, but its quality must also be approved by the Porto Wine Institute. Then it is left in the cask for four to six years, filtered or left unfiltered, and bottled as a ready to drink wine.
The bottles of port wine should be stored on their side to prevent the cork from drying out. They should be kept under fairly constant temperature, between 55 and 60 degrees Fahrenheit, with humidity not below 50 percent.
Vintage port wine must always be decanted before drinking, due to its large amount of sediment. Decanting is done by simply leaving the bottle upright for a full day, and then pouring the contents slowly into a glass decanter, being careful not to dislodge the sediment at the bottom. When sediment begins to show on the bottleneck, stop and discard the rest.
Port wine tongs may be necessary to remove the cork in bottles more than 30 years old. To use these, heat the metal portion of the tongs until it becomes red hot, and then immediately grab the neck of the bottle with the tongs for a few seconds. After pouring cold water over the neck, the cork can be removed with one pull.
The rich, full-bodied types of port wine are usually drunk after a meal, but the lighter tawny and white varieties are highly appreciated as an apéritif. Nuts, melon, cheeses or even desserts are a good choice to accompany port. To best bring its aroma out, pour port into a 5-ounce stemmed glass with sides that slope inward, filling it half to two-thirds.