Port

The Port specification gives a short history of the name. "Porto" identified a wine as early as 1619; by 1699 the name "Wine Port" was in use; and by 1713 a "marca do Porto" was applied. Wine under the name Porto was exported at least from the seventeenth century, to England, Brazil, the United States and Russia. From then until the Second World War almost all Port was exported, and in the twentieth century about 90% still was.

On 10 September 1756 the charter founding the Companhia Geral da Agricultura das Vinhas do Alto Douro, signed by King José I and the future Marquis of Pombal, created the Douro Demarcated Region. The specification calls it the first demarcated and regulated wine region in the world and, before the term existed, the first controlled designation of origin. The IVDP was founded in 1933 as the Port Wine Institute. The present statute of the Douro designations is Decree-Law 173/2009, which brought together more than 18 earlier laws.

Port grapes must come from plots inside the Douro Demarcated Region, about 250,000 ha in north-east Portugal divided into Baixo Corgo, Cima Corgo and Douro Superior. Only a small part of the vineyard may produce Port. Each plot is scored under a points method that weighs soil, climate and cultural factors and is classed on a scale from A to I. Vines grow on mainly schist soils, with patches of granite allowed, often on terraces cut into steep slopes. Irrigation is allowed only in exceptional drought recognised by the IVDP.

The Marão and Montemuro ranges block humid west winds. The region has a wide yearly temperature range, with very cold winters and very hot, dry summers. Mean annual temperatures run from 11.8 to 16.5 °C and are highest along the river and its tributary valleys. Wine may be aged and bottled in the region or in the Vila Nova de Gaia entreposto, a demarcated extension across the river from Porto. It may only be moved there once it has at least 16.1% alcohol.

The specification says Port stands apart through a great diversity of types, intense and persistent aroma and flavour, high alcohol (19-22%), a wide range of sweetness and many colours. Reds run from full ("retinto") through ruby to tawny and light tawny; whites from pale through straw to golden. It attributes this to the region's soils, stoniness, altitude, sun exposure, climate and slope. It also names the native grapes, kept in great diversity, as a decisive element of Port's aroma. The IVDP adds that ruby styles are made to hold the deep red colour and fruit of a young wine. Tawnies are blends aged in cask or vat until they turn tawny, with aromas of dried fruit and wood. Aged white Ports take on a golden colour close to that of an old tawny.

Port is made by adding grape spirit of 77% alcohol to fermenting must; the quantity is fixed each year in the harvest notice. Fermentation must stop with more than 17.5 g/l of grape sugar left. Sweetness terms are extra dry (17.5-40 g/l), dry (40-65), medium dry (65-85), sweet (85-130) and very sweet or Lágrima (over 130). The rules list more than a hundred permitted grapes, among them Touriga Nacional, Touriga Franca, Tinta Roriz, Tinta Barroca and Tinto Cão.

According to the IVDP, Vintage is a single-year wine bottled two to three years after the harvest, which ages in bottle. LBV is a single-year ruby bottled after four to six years in wood. Crusted is a blend kept at least three years in bottle, where it throws a deposit. Colheita is a single-year tawny aged at least seven years in wood. Tawnies with an indication of age are sold as 10, 20, 30 and 40 years old, and white Ports may also carry these ages. Port may not leave the region or Gaia in bulk; it must be bottled there.