That is the question…
When and why should we decant a wine? Instruction manuals can be a bit dry so bear with.
Decanting has three distinct advantages: the separation of the wine from its deposit or sediment, oxidation or aeration of the wine and changing the wines temperature.
Avoiding the sediment is obvious as polymerised tannins not only look disturbing in the glass but are deeply unpalatable to the poor soul unfortunate enough to swallow them.
Firstly remove the capsule (that’s the fancy metal – formerly lead bit – that covers the cork) entirely, so that you can see the wine as it comes up the neck. Then carefully uncork without agitating the bottle and disturbing the sediment. If it comes from a rack then stand it up for a few hours or ideally the day before.
Wipe the neck of the bottle (inside and out) with a clean cloth so you can clearly see the sediment as you pour. Tilt the bottle and the decanter at a slight angle over a candle (Dickensian but very Christmassy) so that you can observe the movement of the deposit, adjusting the angle as you pour - like bending, but not dramatically breaking, a twig.
Oxidation of the wine is important as it helps accentuate the smell or nose, but if this happens too abruptly, or for too long, it can ruin the wines subtlety and freshness.
Do not decant old wine, just open and pour immediately to retain its fragile and fleeting charm.
Exposure to air can vary enormously with grape structure and type, so some knowledge of what you are serving, how old it is, and when you’re going to drink it is very important. Fortified wines like Port and Madeira have already undergone substantial oxidation in cask so can sit in a decanter for hours. Even young wines respond to aeration, and while they may not throw a sediment – due to modern fining and filtration techniques – they benefit greatly from a mellowing of often fierce aromas and aggressive tannins.
Decanting also helps the wine to ‘naturally’ come up to the temperature of the room in which it is to be served. Remember the decanter should also be the same temperature as the room. A young wine served from a bottle takes longer to come to room temperature than a decanted wine taking, on average, about three hours to rise from 11 to 18 degrees centigrade in a room of around 22.
A sommelier will do this for you in a restaurant, but remember they are much more flash than they used to be and insist on sampling some of your precious vino!