Vineyards along the Douro River in the North of Portugal have been producing wine for thousands of years. The English discovered Portuguese wine in the 1660s, when political problems between England and France cut off their access to Bordeaux wines. English merchants living in Portugal offered up the rich wines from Duoro as a substitute.

However, the first few shipments that reached London had spoiled during the long sea voyage. Adding brandy preserved the wine. This fortified wine was dubbed “port.” Enthusiasm for port drew hundreds of English entrepreneurs to the town of Oporto at the mouth of the Douro River to open port production businesses.

In 1820, there was a particularly ripe vintage. Not all the grape sugars in the juice could be fermented into alcohol, resulting in an extraordinarily sweet and rich wine. English consumers clamored for more, so Duoro producers stopped fermentation earlier by increasing the amount of brandy they added. Less fermentation time meant more grape sugars remained in the wine. By 1850, standard Porto wine was about 20 percent alcohol by volume and 10 percent residual sugar.

As the English empire grew so did their love of port. Several of England’s former colonies started producing port wine for themselves and for export to England. Two of the most successful? Australia and the United States. In fact, the wine business in both countries started primarily to produce port.

The fortified wines of Portugal are often labeled as Porto or Oporto. But other countries—including Australia and the US—use the English translation of “port” for wines produced in the Porto style.