John Hale, of Dunedin, asks :-

Once upon a time wine bottles had corks, and after being opened needed “breathing.” Why don’t the current metal screwcaps need the same performance? Was it only a ritual or does wine still need breathing?

Bernard Newman, a wine scientist at Lincoln University, responded.

The ‘breathing’ treatment – involving opening a bottle of wine and leaving it to stand for some time (perhaps even a few hours) before pouring it has been considered beneficial by some wine consumers.

In reality this action would have a small effect as there is little surface area to react with the air and the time allowed for any oxidation reactions is quite minimal.

An experiment to show this would be to have three glasses of the same wine – two glasses from a bottle opened a few hours before the other one (you could also try a set of glasses with two being from a freshly opened bottle of the same wine) and see if you can spot the ‘odd one out’. Planning such an experiment so that the tasters don’t know which glass is which makes this test (called a Triangle Test) quite convincing.

Screw cap wines would respond to this ‘breathing’ treatment just as well as a wine that is bottled with a cork.

A more effective way to ‘aerate’ a wine is to ‘decant’ it. The merits of this action are debated by wine connoisseurs. Decanting is primarily used to avoid getting any sediments that may naturally be generated in an aged wine (typically an older red wine or port wine will produce sediments).

Another reason for decanting is to aerate the wine – this can help remove some of the slightly ‘stinky’ aromas a wine may have generated in bottle. Just as effective is swirling such a wine in the glass.