Port wine: what it is and how to read the label

To fortify a wine is to stop the alcoholic fermentation of a grape must by adding something to it. Port is exactly that. In the vat, yeasts turn the sugar of the grape into alcohol; when the must reaches the wanted degree of sweetness, a spirit of vinous origin is poured in. Fermentation is interrupted and part of the grape’s natural sugars stays in the wine, writes the Instituto dos Vinhos do Douro e do Porto (IVDP), the public body that administers the designation.

The proportions are set down. The spirit used is at 77 per cent by volume, and the commonest proportion is one part of spirit to four parts of must, the IVDP states. The finished wine is generally 18 per cent for the ordinary categories, 19 per cent for the special ones, and up to 22 per cent at most. That is why a port is stronger than a table wine: part of its alcohol does not come from the grapes in the vat but from the bottle poured into it.

In European nomenclature port is not a still wine but a liqueur wine: its specification states that the designation of origin Porto may be used only by a fortified wine falling in the liqueur wine category, and that the types of port are tawny, ruby, white and rosé. On sugar, the IVDP ranges ports on a scale running from extra dry to very sweet, by way of dry, medium dry and sweet: sweet therefore does not mean the same thing from one bottle to the next.

Port can come from one place only, the Região Demarcada do Douro, in the basin of the river Douro, in northern Portugal. The IVDP counts about 250,000 hectares there, of which 43,808 are planted with vines, roughly 18 per cent of the area. It is divided into three sub-regions, downstream to upstream: the Baixo Corgo (13,204 hectares of vineyard), the Cima Corgo (20,427) and the Douro Superior (10,177). The designation’s specification describes these three as more restricted geographical areas inside the region, listed municipality by municipality and parish by parish.

The climate depends on two mountains. The Marão and the Montemuro form the barrier that shelters the region from the damp westerly winds off the Atlantic, the IVDP explains, hence very cold winters and hot dry summers, with rainfall from 380 to 1,200 millimetres a year depending on the place and mean temperatures from 11.8 to 16.5 degrees. The vine grows there on terraces cut into the slopes, held by schist walls.

The wine is born upstream, but carries the name of the port it left by, and for a long time it could only age opposite that port. In 1926 the Douro wine entrepôt was created at Vila Nova de Gaia, on the other bank of the river: it was the only place where port could be stored. Direct sale from the Douro was allowed only in 1986, the same year the regulation of the Vinho do Porto designation of origin was approved, according to the IVDP’s chronology.

Because an agricultural product there received, for the first time, both rules and a body charged with applying them. On 10 September 1756, Sebastião José de Carvalho e Melo, minister to King Joseph I and the future marquis of Pombal, created the Companhia Geral da Agricultura das Vinhas do Alto Douro. It drew up a cadastre of the plots, set maximum stocks and prices by quality, and forbade adding to the wine anything that changed its profile. That is where the IVDP’s formula comes from: the demarcated Douro region is held to be the first designation of origin in the world.

The demarcation on the ground came after. The IVDP puts the so-called Pombaline demarcations between 1757 and 1761 and sees in them the first demarcation of the Douro wine region; Helena Teles and Patrícia Soares, of the Missão Douro office, tie the delimitation and regulation of the region to the creation of the Company in 1756. Both say the same thing in two stages: the rule first, the boundary stone second.

Those stones still exist. The Douro museum counts 201 granite markers planted in 1758, then 134 in 1761, 335 in all, carved with the word Feitoria to mark the land fit to produce export wine. Each was about two metres high, part of it buried, thirty centimetres wide and twenty thick. In 2007 the survey run by the Douro museum had located only 105: buried, built into house walls, reused as planters in cellars and stables, and even in masonry works. The last known inventory before that dated from 1949 and recorded 103.

The Company was a Portuguese affair, and its statutes said so: foreigners could be shareholders but not directors, notes the file the National Archives of Brazil devote to the wine economy in Portugal. The English, Dutch and German merchants settled in Porto in the seventeenth century, whose trade the IVDP notes, were therefore financing a commerce they did not run.

Two words give the style, and ageing is what separates them. A ruby keeps a deep, intense ruby or purple colour which, the IVDP writes, indicates youth and concentration; in the mouth, body, tannin, fresh black fruit. A tawny moves towards amber and gold, and that colour is the result of prolonged oxidative ageing in wood: lighter than a ruby, supple in texture, tasting of nuts, almonds, caramel and dried figs.

The other mentions are dated promises, and they are earned before a tasting chamber created in 1934 within the Port Wine Institute, held today by the IVDP, which marks the wine out of ten. A vintage comes from a single harvest of exceptional quality, is certified between January and June of the second year and bottled by 30 July of the third; it needs 9 out of 10. A Late Bottled Vintage (LBV) also comes from a single harvest, but is bottled between March of the fourth year and December of the sixth, and 8 out of 10 is enough.

A figure on the label is not an age. Ports with an age indication (10, 20, 30, 40, 50 years, then 80 years and VVO) are blends of several vintages long aged in wood, whose character must match the age announced. The IVDP requires 8 out of 10 up to 50 years and 9 out of 10 beyond, the mention Very Very Old being reserved for wines with more than eighty years of ageing.

Three more words turn up often. A colheita is the wine of a single harvest aged at least seven years in wood. A garrafeira spends four to eight years in wood, then at least fifteen in glass, and may carry Velho beyond twenty. A Reserva is a blend of several years, with six years of wood at least for a tawny or a white, and a mark of 7 out of 10. All these thresholds are the ones the IVDP publishes.

The landscape this wine made is listed too. On 14 December 2001 the Alto Douro Vinhateiro was inscribed on UNESCO’s World Heritage list in the category of evolving and living cultural landscapes: that is the date and the category given by the IVDP’s chronology and by Helena Teles and Patrícia Soares’s study. The property covers 24,600 hectares across thirteen municipalities and is, they write, the most representative and best preserved part of the demarcated Douro region, whose 250,000 hectares serve as a special protection zone.

Three criteria were kept, which Teles and Soares sum up thus: the Upper Douro has produced wine for nearly two thousand years and its landscape has been shaped by human activity (criterion iii); its components, terraces, quintas, hamlets, chapels and roads, represent the whole range of activities tied to wine production (criterion iv); the whole is an outstanding example of a traditional European wine region, reflecting the evolution of that human activity over time (criterion v).

The landscape is not fixed for all that. Phylloxera, detected in the Douro in 1863 according to the IVDP’s chronology, ruined whole hillsides: the abandoned vineyards, the mortórios, still carry the mark of it. Reconstruction was done with American rootstock grafted with regional varieties and with wider terraces, their walls stronger and straighter, Teles and Soares describe. In other words, what is photographed today from the river is largely a landscape from after the catastrophe.