People in the Douro valley say that babies and port wines are often born at night. Port producers let the grape juice ferment for about three days. They choose the perfect moment to add a neutral grape spirit (aguardente) that stops the fermentation before the yeast eats all the grape sugar. This moment often comes in the middle of the third night.

Most of the Douro grapes are used to produce ruby ports. These inexpensive ports are first stored in cement or stainless steel vats to prevent oxidation and then bottled. The result is a wine that retains a dark ruby color and fresh fruit flavors.

When the quality of the grapes is exceptional, port-wine producers declare a vintage year. These ports are stored in wood casks for one or two years and then bottled. With little exposure to air, the wine is dark red. Aging brings out complex flavors, such as notes of vanilla, chocolate, and blackberry.

The best grapes are also used to produce tawnies. These ports are aged for many years in casks made of Portuguese chestnut and oak. This aging process creates complex flavors and gives the wine a silky mouthfeel. The small amount of air that circulates through the tiny pores of the wood oxidizes the wine slightly, changing its color from red to amber.

It is wonderful to share a glass of ruby port with new friends. But there’s nothing like drinking old vintages and tawnies with old friends.