How To Decant Vintage Port
Port decanting has a bit of mythology surrounding it and most people seem to imagine it is difficult to do correctly. In reality all it really requires is a spare clean bottle (a port decanter if you have one) and a steady hand to pour. The first question you should ask is do I need to decant the port.
Tools for the job: Clean decanter and decanting funnel. The decanting funnel is not essential but makes decanting a lot easier.
Before you start, have your clean decanter at the ready (alternatively, you could also use a clean, empty wine bottle or a jug).  If there is time, stand the bottle upright for a few hours prior to serving. This allows the sediment to settle and will make the decanting a little easier.
Without shaking the bottle too much and with the bottle still vertical, remove the foil and wipe the top of the bottle clean. Gently ease the cork out. The older the port the more delicate the cork will be. If the cork crumbles do not worry as the bits of cork can be removed using a decanting funnel.
Slowly and steadily, pour the port into the decanter through your decanting funnel.
Some ports have a splash of white paint on the bottle, this is there to tell which way up it was cellared; this mark should be uppermost during decanting.
A lamp or candle flame behind the bottle will help you see if any sediment is approaching the neck – This is when you should stop pouring.
TOP TIP: Do not waste sediment which, being the residue of old grapes skins, is a natural substance rich in flavour and it is not harmful. These last drops in the bottle will enhance many soups or stews.
How the port keeps once opened: vintage ports should ideally be consumed within 72 hours of opening. Having spent its 'life' in a bottle with little contact with the air, it quickly oxidises. Other styles, like the late bottled vintage and the aged tawny ports, can be consumed from four to eight weeks (or longer) from the date of opening.