Hey all,

So it seems like it is an established "fact" that allowing wine to "breathe" for a while before drinking it makes it taste better or something. Does this belief have a scientific explanation?

Does the wine absorb oxygen or nitrogen? Or does it release gases into the air? Or both?

Is a wine/air interface area of one square inch enough to allow an efficient gas exchange throughout three-quarters of a litre of stagnant fluid?

What chemical reactions are going on, if any? Are these reactions enough to cause a change in the taste of the wine in a time period of 20 minutes?

clop

I was told that the purpose of letting it breathe is to allow any traces of SO2 used in the winemaking process to escape.

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Olsen the moderator.

A good article from the NYT on the subject:

http://query.nytimes.com/gst/fullpag...52C1A96F958260

Not so much the sulphur dioxide used in production, but sulphur dioxide (and mercaptans) produced by mould or bacteria in the cork. This produced something called "bottle stink", which would dissipate in a few minutes if you opened the bottle a little early and carefully wiped the rim. But it's very rare now.
You can also get a condition in which the wine itself is said to be "reduced": the control of oxygenation during production has gone a little awry, so that the wine contains an excess of reduced sulphur compounds, like hydrogen sulphide. The wine has an odd gunpowdery smell when you uncork it. That can be fixed to some extent by aeration, but "breathing" is useless, because of the small surface area for gas exchange in the neck of the bottle, as clop points out. The most vigorous bit of aeration I ever saw was performed by a South African oenophile who owns a hotel on the south side of Loch Tay, here in Scotland. Not liking the nose of the wine he was about to serve, he poured the bottle into a very broad-based decanter and then swirled it so much that it splashed, keeping the process going for twenty or thirty seconds. If you believe that aerating wine can have a useful effect getting rid of reduced compounds, that's the sort of thing you have to get up to.

Grant Hutchison

Thank you for all the replies. I'm still a little skeptical though. If I have some hydrogen sulphide dissolved in a litre of water I'd be surprised if shaking it for 20 seconds is going to remove it all, or even a significant portion of it.

Interesting in the NYT article that aeration can ruin wine within the space of a few minutes. Can this be tested objectively? I guess we could attribute a colour change to enzymes like polyphenyl oxidase, but would that change the taste too?

What we really need is an experiment where a large group of participants unknowingly taste fresh wine, and wine that has been allowed to breathe, and vote for their favourite. I wouldn't be surprised if the results were random. To me this breathing idea has all the hallmarks of addiction ceremony.

clop

Until this thread, I had always thought that "breathing" and "aeration" were the same thing, and that they meant swirling a glass of wine before drinking (which of course means the wine's been poured into the glass already). I never heard of just opening the bottle for a while before even pouring. Is there a name or purpose for what I'm talking about, or does it just mean some people are fidgety or like the way the liquid looks in motion or something like that?

Its a fact that letting the wine breathe has a significant impact on the flavor of a premium wine and it has been explained to me as allowing oxygen to get to the wine (which also quicky causes it to age). I can't explain the chemical processes at work.

I personally suspect, that allowing the wine to breathe (accelerated by swirling) releases the aromas quicker which in turn enhances the flavor since olfactory sensations are essential to good taste.

The business of swirling the wine in the glass before tasting is called "agitation": the idea is to get the volatiles into the air within the bowl of the glass in reasonably high concentration, so that you can smell them before taking your first taste. Agitation without smelling is also a means of aeration, if you want to get rid of volatiles you'd rather not encounter, like hydrogen sulphide.

Grant Hutchison

Aeration is claimed to be as much about chemistry as physics: by aerating the wine with that twenty-second shake-up, you introduce dissolved oxygen into what was essentially an anoxic environment, as well as removing volatiles by diffusion. It's presumably chemistry that's being invoked in the reported "fragility" of old wines; but I've no experience of that, since the only very old wine I've tasted had died in the bottle.
But it's certainly common experience that a wine changes its character while you're drinking it, as Veeger reports: reds that start off a little disappointing can become more complex as time goes on, for instance. Some of that is presumably the physics and chemistry of a complex chemical mixture exposed to oxygen for the first time in years; some of it is the gustatory equivalent of "getting your eye in"; some of it's no doubt psychological.

Grant Hutchison

though it doesn't happen much these days, the process of decanting a wine was not uncommon ... more effective than uncorking alone, and far more couth than shaking the bottle ...

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Yes, decanting used to be a way of excluding sediment, as well as aerating. But nowadays red wines are filtered so that sediment is minimal. So port seems to be about the only thing that is regularly decanted.
(My fella didn't shake the bottle, by the way: he decanted into a broad-based decanter, like the one pictured here, giving a big surface area for gas exchange, and then shook the thing from side to side. You can get the same effect by just letting the wine stand in such a decanter for a while, if you're not in a rush to drink it.)

Grant Hutchison

I lived for over a year on the edge of the Italian wine producing region known as Collio Orientali. These people take an enormous pride in their red wines and a few unique whites which are only produced there. I have heard every conceivable farmers tale about the proper way and time to produce and drink wine. I have also had the pleasure of sampling some very old reds of which about half spoiled immediately upon opening (or perhaps prior).

One thing that struck me was the ability of these master wine makers (and drinkers) to taste the wine with their noses. They could tell the quality long before it touched the tongue. In fact, the only time they swirled the glass was to collect the aroma on a freshly opened bottle. I never seen anyone there, let it "breathe".

btw - most of the best wines I drank, had hand-written labels giving the name of the grape and year - nothing more.