But you do need to know that simply uncorking the bottle and letting it sit for an hour will do nothing to improve the taste or the smell of the wine, and you do need to know that most white wines do not need to breathe at all.
What Happens When a Wine is "Breathing" As you have probably guessed, you are not going to hear your wine inhaling and exhaling.
Letting wine breathe is simply letting it aerate.
By exposing the wine to the air, the tannins in the wine will mellow and give your wine a softer taste.
This oxidation of the wine changes its chemistry a bit, so the smells are stronger and the sharpness of the acids is mellowed.
This mellowing makes it nicer to really savor the wine, and thus you taste more flavor.
Which Wines Need to Breathe Young red wines are the prime candidates for aeration.
By "young" I mean anything less than four years old.
Older wines (sometimes called "mature") have aged eight years of more.
Also, the heavier-bodied a red wine is, the more it will benefit from a longer aeration time, like an hour.
For example, a young Bordeaux or a Cabernet Sauvigon will probably benefit from aerating for an hour, where a much lighter Merlot or Pinot Noir would need barely five minutes or less to hit its peak.
While it is said that white wines do not need to breathe, there are exceptions.
Some Chardonnays will benefit from a few minutes of aeration.
Really, the only way to tell if a wine needs to breathe is to taste it.
If there is a sharpness or a bitterness that you do not like, aerate the wine for five to ten minutes and see how it tastes.
If it is better, but needs more time, you can let it sit in a decanter for a bit.
Unfortunately, if this is your first time serving this kind of wine or this vintage of wine, you are going to be doing a bit of guesswork.
How to Let a Wine Breathe As mentioned before, simply uncorking the bottle is not enough.
You need either a decanter, or just a wine glass.
To let the wine breathe, pour it into the decanter or the wine glass from as high above as you are comfortable with.
This is why the decanter helps -- unless you have a very large wine glass, you probably are not going to be comfortable pouring from any higher than six inches above the glass.
You can use almost any wide-mouthed container as a decanter.
Even a vase will do in a pinch.
You can also ask for wine to be decanted for you at a restaurant.
And this decanting is also why all those waiters made such a show of pouring out the first glass -- they were not being exhibitionists, they were trying to get as much as air as possible into the wine.
OK, maybe some of them were being exhibitionists.