Decanting is just a way of getting more flavour and aromas out of your wine, allowing some air to get to the liquid in the process of pouring from one container (the wine bottle) to another (your decanter). It’s also good for removing sediment from unfiltered wines, aged wines or vintage Port.
Not to worry, you don’t need a crystal decanter, as lovely as they may be. A cheaper version or even a jug will do.
If the wine you’re pouring is likely to have a deposit (eg if the wine is over ten years old, a vintage Port or an unfiltered/natural wine), stand the bottle upright for at least an hour, preferably overnight, before pouring the wine slowly off the sediment. Do this until you see the sediment (or ‘dregs’) appear at the bottle shoulder.
Young robust wines like the chance to breathe in a decanter so don’t be afraid to do this several hours before drinking.
There’s a bit of a debate around decanting old wines. Some say they’ll lose their perfume by decanting, while others argue old wines need ‘waking up’ – you certainly don’t want to leave old wines in a decanter for too long.