Port Wine of the Duoro Valley
The Duoro Valley cradles the Duoro River whose name comes from Rio do Ouro (River of Gold) and which has always been Porto’s lifeblood. The region has long been associated with port producing vineyards, and over the millennia, this otherworldly, ever-changing terrain has been sculptured by hard working wine growers. The sublime landscapes of neat rock terraces wrap around every precipitous hillside, and the whitewashed quintas, port producing estates, dot the valley. Traditionally, the wine was taken downriver in flat-bottom boats called rabelos, to be stored in barrels in cellars in Vila Nova de Gaia, just across the river from Porto. Further upstream, the Duoro River, the third-longest in the Iberian Peninsula (after the Tagus and Ebro) forms a natural border between Spain and Portugal for 70 miles of narrow canyons. Historically, it formed a barrier to invasions, creating a cultural and linguistic divide. Recently, fifteen dams have been built on the Douro to regulate the water flow, generate hydroelectric power, and allow navigation through locks.
The port wine-producing Douro Valley region is the third oldest protected wine region in the world after the Tokaj region in Hungary, established in 1730, and Chianti, in 1716. In 1756, during the rule of the Marquis of Pombal, the Companhia Geral da Agricultura das Vinhas do Alto Douro was founded to guarantee the quality of the product and fair pricing to the consumer. After the Methuen Treaty of 1703, port became very popular in England, when merchants were permitted to import it at a low duty, while war with France deprived English wine drinkers of French wine. British importers could be credited for recognizing that a smooth, already fortified wine that would appeal to English palates would survive the trip to London. In 1678, a Liverpool wine merchant sent two new representatives to Viana do Castelo, north of Oporto, to learn the wine trade. While on a vacation in the Douro, the two gentlemen visited the Abbot of Lamego, who treated them to a "very agreeable, sweetish and extremely smooth" wine," which had been fortified with a distilled spirit. The two Englishmen were so pleased with the product that they purchased the Abbot's entire lot and shipped it home. The continued British involvement in the port trade can be seen in the names of many port Shippers and brands: Broadbent, Cockburn, Croft, Dow, Gould Campbell, Graham, Osborne, Offley, Sandeman, Taylor, and Warre being amongst the best known. The British involvement grew so strong that they formed a trade association that became a gentlemen's club.
Port can only be produced from grapes grown and processed in the demarcated Douro region. The wine produced is then fortified by the addition of a neutral grape spirit known as aguardente to stop the fermentation, leaving residual sugar in the wine, and to boost the alcohol content. The wine is then stored and aged, often in barrels stored in a Lodge (meaning "cellar") as is the case in Vila Nova de Gaia, before being bottled. The reaches of the valley of the Douro River in northern Portugal have a microclimate that is optimal for cultivation of olives, almonds, and especially grapes important for making port wine. Touriga Nacional is widely considered to be the most desirable port grape but the difficulty in growing it and the small yields make Touriga Francesa the most widely planted grape. While a few shippers have experimented with Ports produced from a single variety of grapes, all Ports commercially available are from a blend of different grapes. Grapes grown for port are generally characterized by their small, dense fruit which produce concentrated and long-lasting flavors, suitable for long ageing. Port wine is typically richer, sweeter, heavier, and higher in alcohol content than unfortified wines, and usually has 19% to 20% alcohol content.
Port is commonly served after meals as a dessert wine in English-speaking countries, often with cheese, nuts, and/or chocolate; white and tawny ports are often served as an apéritif. In Europe all types of port are frequently consumed as aperitifs.
Port from Portugal comes in several styles, which can be divided into two broad categories: wines matured in sealed glass bottles, and wines that have matured in wooden barrels. The former, without exposure to air, experience what is known as "reductive" ageing. This process leads to the wine losing its color very slowly and produces a wine which is smoother on the palate and less tannic. The latter, being matured in wooden barrels, whose permeability allows a small amount of exposure to oxygen, experience what is known as "oxidative" aging. They too lose color, but at a faster pace. They also lose volume to evaporation (angel's share), leaving behind a wine that is slightly more viscous.
Most port wines will be on one of these categories:
Ruby port is the least expensive and most extensively produced type of port. After fermentation, it is stored in tanks of concrete or stainless steel to prevent oxidative aging and preserve its bright red color and full-bodied fruitiness. The wine is usually blended to match the style of the brand to which it is to be sold. The wine is fined and cold filtered before bottling and does not generally improve with age, although premium rubies are aged in wood from four to six years.
Rose port is a very recent variation on the market, first released in 2008. It is technically a ruby port, but fermented in a similar manner to a rosé wine, with a limited exposure to the grape skins, thus creating the rose color.
Tawny ports are wines usually made from red grapes that are aged in wooden barrels exposing them to gradual oxidation and evaporation. As a result of this oxidation, they mellow to a golden-brown color. The exposure to oxygen imparts "nutty" flavors to the wine, which is blended to match the house style. They are sweet or medium dry and typically consumed as a dessert wine, but can also pair with a main
White port is made from white grapes, such as Malvasia Fina, Donzelinho, Gouveio, Codega and Rabigato, and can be made in a wide variety of styles. Ordinary white ports make an excellent basis for a cocktail while those of greater age are best served chilled on their own. Sweet white port and tonic water is a commonly consumed drink in the Porto region. There is a range of styles of white port, from dry to very sweet.