When people talk about letting a wine breathe, this is really about exposing the wine to oxygen by allowing it to aerate before you drink it.
There is a lot of debate about the necessity of doing so, but aerating some wines is broadly considered to release more of the wine’s aromas and soften tannins – which can be particularly helpful on a young, full-bodied red wine.
You can let a wine breath by decanting it, but several experts believe that simply swirling the wine in your glass can have the desired effect in many cases.
There are kitchen gadgets that claim to aerate wine, although ‘several don’t make much difference’, Ronan Sayburn MS told Decanter in 2016.
What most experts can agree on is that just opening the wine and leaving the contents in the bottle won’t really help.
The neck opening is so small that your wine isn’t going to get enough air in time for dinner, nor probably even for tomorrow morning’s breakfast.
On the other hand, this feature also helps the wine to last for a couple of days – and sometimes longer – after opening.
When should you let a wine breathe?
Swirling your glass is effectively aerating the wine, even if briefly, but what about letting a wine breathe for a longer period of time?
‘I always give the same advice to people,’ said Clément Robert MS, a Decanter World Wine Awards judge and named the UK’s best sommelier in 2013.
‘It is important to have researched the wine; to know the character of the wine and how it should taste,’ he told Decanter.com in 2017.
‘If you were, for example, in the presence of a fragile wine, like an old vintage bottle, then I would not risk aerating it too much. I would probably open it in advance and try to find the right type of glass.
‘Personally, I would recommend a Bordeaux glass rather than pouring it in to a decanter.’
If decanting a wine, Robert said that he would allow it to sit in the decanter for around one hour, on average.
Does it really make a difference to taste?
You’ll hear many wine critics talk about how a wine’s character can change in the glass over time, and over several days once the bottle has been uncorked. Perhaps you have also noticed this yourself.
As mentioned above, it is commonly asserted that aerating some wines – particularly bolder reds – can help to soften tannins and release fruit flavours.
If your wine has mild reductive aromas like struck match or sulphur-like odours on opening – and you’re not a fan – then allowing the wine to breathe can reduce their intensity, as Natasha Hughes MW writes.
In 2016, an article in the Journal of Agricultural Chemistry found evidence that ethanol evaporates once a wine has been poured into the glass, slightly lowering the abv content. It said this was strongly influenced by exposure to air.
As part of this process, the researchers noted that, ‘Evaporation also resulted in decreases in the concentration of some fermentation volatiles and a perceptible change in wine aroma.’
Professor Andrew Waterhouse, a wine chemist at UC Davis in California, wrote in Scientific American back in 2004 that ‘a wine’s aroma will change during the first 10 to 30 minutes the bottle is open’.
He said that decanting accelerates the breathing process by encouraging volatile aromas to evaporate and emphasising fruit and oak aromas.
However, he also said that decanting may not improve less complex wines designed for immediate consumption, while some white wines’ fruit aromas could actually lose intensity.
Others have argued that advances in winemaking mean that fewer wines require the sort of aeration that might have been considered beneficial in the past.
A main advantage of decanting wines, and especially older vintages, is that you won’t get a glass full of sediment as you near the end of the bottle.
However, some producers prefer to double decant younger wines, too, and particularly those that have high tannin levels.
This involves pouring the wine into a decanter and then back into the bottle.
‘It’s good for the young vintages to do this, for more aeration,’ said Pierre Graffeuille, director of Château Léoville Las Cases, at a masterclass of the St-Julien estate’s wines held during Decanter’s Bordeaux Fine Wine Encounter 2017.
‘It’s definitely better to double decant if you can – give it at least one hour,’ he said.
Be careful with older vintages, which can be much more sensitive once opened and may lose fruit aromas much more quickly.
‘You could transform a great wine into vinegar by letting it breathe for too long,’ said Clément Robert MS. ‘Old vintages are the most fragile.’
He added, ‘Personally, I would not carafe or decant a Pinot Noir as I like the primary characters of the grape.’
In the case of most white wines, Steven Spurrier said in 2016 that, ‘because they don’t have tannins, the need for aeration is rarely necessary.
‘However, I would decant young and old white Rhônes and mature Alsace Rieslings – and both at the last minute.’
Do try it at home
Perhaps the best thing to do is conduct your own research, which may necessarily involve opening a bottle or two.
Do you notice a difference in the wine depending upon how long it has been open, or sitting in a glass or decanter?
This article was originally published on Decanter.com in 2017. It was updated by Chris Mercer in May 2020.