Decanting is a simple process and involves separating the wine from the crust by pouring it slowly and carefully into a decanter or another vessel leaving the sediment behind in the bottle.
Ideally a bottle of Vintage Port should be stood upright for several hours before it is decanted so that any loose particles of sediment have time to settle to the bottom of the bottle. Some Vintage Ports have a white chalk mark painted on one side of the bottle. This indicates that the bottle has been stored with the white mark uppermost and it is advisable to hold the bottle in the same position when decanting it. A vintage port should be decanted three or four hours before drinking.