ALL OF US who love wine will have had the same experience. We open a bottle, it doesn’t impress us at first, but as the meal goes on it seems to wake up, so that by the time we’ve finished the bottle we are astonished at how good it is. “How the wine has opened up” we say, assuming that it’s the contact with the air that has released those previously hidden aromas. Some of us will even decant any red wines that are more than a few years old in the hope of getting the aeration done from the start.

There is, however, a problem. Aerating wine has been put to scientific test a number of times. The answer is usually the same: that decanting does NOT improve the flavour (though it does mean you don’t get a sludge of sediment in your last glass). Take the experiment organised by Decanter Magazine in July 1997. A number of world experts, including our own Hugh Johnson, were assembled. They tasted a number of red wines from Bordeaux, prepared in five different ways. Samples were poured as soon as the cork was pulled, or allowed to sit in an opened bottle for a few minutes or hours, or decanted a few minutes or hours ahead of the tasting. When averaged out the differences weren’t great but the treatment that was marginally the best was pouring straight from the just-opened bottle!

How can this be? Hugh Johnson himself has puzzled over this and suggests that the answer is that every bottle of wine behaves differently. The older the wine the more true this is. When you do a trial you average up the scores and so lose the individual variations. So, in the Decanter trial the 1961 Mouton-Rothschild might have improved with decanting, but this was nullified by the fact that the 1990 Mouton-Cadet worsened.

Can we give any guidance about what should be decanted and what should be drunk straight away? White and rosé wines don’t need aerating; it’s the pigment molecules in red wine that can benefit from exposure to the air. Young and fruity red wines are unlikely to benefit; indeed they can deteriorate quite quickly once opened. It’s the older better reds that are hard to predict. If they are ‘closed’ (meaning ‘without much flavour’) they may benefit from being allowed to breathe. They may even be better next day if re-corked and left.  But if they are ‘alive’ as soon as opened they may go ‘flat’ if left. So the answer is: no, no guidance can be given.

Some friends open red wine an hour before pouring as a compromise. The experts seem agreed that that won’t help. The amount of wine in contact with the air is too small. If you really want to aerate the wine without decanting, pour a little out to make some room in the bottle, re-cork it, shake vigorously for 5 seconds, then pour the rest back in. Don’t do it if there’s any sediment, of course.

I’ve abandoned decanting. I try to get through a bottle slowly enough to spot if it’s improving. I swirl it in the glass to see if that makes a difference. And if the sediment starts to come through I get the tea-strainer out.

Andrew Polmear