Port as we know it was a British invention. Portuguese wines have been drunk in Britain from as early as the mid-14th century. To ensure that they were stable for travel to Britain, brandy was added before shipment. But it was not until around 1730 that it was found that if the brandy was added to the wine during fermentation, the fermentation process would be stopped, leaving enough sugar in the wine to make the usual acid and astringent Portuguese wines of the time more palatable.
The most popular styles in Britain are the late bottled vintage (LBV) and vintage styles. The LBV port is from a specified vintage but has been aged in cask for six years and is bottled when ready for consumption. This style tends not to throw a sediment.
A vintage port is one from a vintage that has been declared exceptional. It is usually from the best vineyards and is bottled when only two years old. This continues to develop in the bottle and often will not reach its peak for 10 or 20 years. This will throw a deposit so it is necessary to decant a vintage port.
Alan Johnson is managing director of Elegusto Wines