When and how much do you let a wine breathe?
I have a decanter/aerator: large, mushroom-shaped. I typically buy $10-30 wines with $16 being about average.
How do you know whether it is important to decant and aerate? If you have a young, green wine with a lot of tannins, will it ever get significantly better with lots of aeration and/or hours of waiting versus, say, 15-30 minutes or a lot of swishing in the glass?
I read where a mature wine might suffer from any oxygenating. Most I buy are less than 8 years old...
Is there any rule of thumb? Do you try it every 15 minutes to see if it is "opening up? Do you give up after an hour and just drink it or cook with it?
What is too much breathing? I watch wine experts swirling and swirling prior to drinking-but they are usually pouring straight from the bottle. Can you tell when it has "opened up" on smell alone?
I've seen great improvements with time and aeration but I confess, I don't know when to stop...
It depends a lot on the wine. Big Aussie Shiraz is much better after several hours, and even 6 or 8 in the decanter. On the other hand, older wines do tend to breakdown quickly when exposed to air. As a rule of thumb, I like to decant wines like Shiraz, Zinfandel, and Pinot Noir at least an hour before I'm going to serve it, and in the case of a big Shiraz like a MollyDuker, for at least three. Chards also benefit from about half an hour or so in the decanter.
On the other hand, a Pinot Gris is fine right out of the bottle, but even that gets better as the evening progresses. The best thing to do is experiment. Pour a glass of wine and taste it right away, then leave it alone for half an hour and come back to it, and repeat half an hour later. You might be suprised at how much better it tastes as the evening goes on.
That's what I used to do. Now, I have the decanter. It has so much more area exposed to the air that I'm not sure how long to pour it in there before I plan on drinking. I remember being at a winery where the server opened a fresh bottle of cab, swrled it around in the decanter quite a bit and then we sampled it; all within five minutes, or less. We liked it so much that we bought a few bottles; opened one that evening and were amazed how bad it tasted, till it finally opened up.
I didn't know that chilled whites opened up and got better.
As most others have stated, it is totally dependent on the wine. Some will be "enhanced" by the decanting/aeration, while others will not. Some might well "die" in the process, loosing what fruit and nuances, that they were holding on to.
If you are unsure, and wish to decant/aerate the wine, pour yourself a little, into a glass, and then pour the rest into the decanter. Keep tasting the wine in your glass, and when it seems about right (your taste is the determining factor), pour the wine for your guests.
Very many of my sommelier acquaintances, in the US and abroad, pour many whites into a caraf. I find that bigger white Burgs do benefit greatly from this little pouring.
In the end, it is up to the wine, and your tastes, that will determine whether there is benefit.