aerating and decanting wine
Aerating and decanting wine.
You may have seen the process of decanting wine in a restaurant, or seen all the fancy aerators that were all the rage this Christmas season at places like Crate and Barrel. What are they, how are they different, and do they really do anything?
A decanter is the large crystal or glass container, sometimes shaped like a fat, wide-bottomed bottle, other times like a pitcher, sometimes like an inexplicable blown-glass fantasy, into which wine is poured before serving. Sometimes, wine is poured into a decanter to actually decant it, sometimes just to aerate it. To decant in wine terms is the same thing it is in chemistry - to carefully pour off the top layer of a liquid without disturbing the solids that have settled to the bottom in order to separate them. Some wines, especially older reds, develop sediment. It's not harmful, it's just gritty and generally considered distasteful. This is the reason for the whole rigmarole with careful handling and angled baskets for such bottles in high end restaurants. The idea is to avoid shaking and mixing the sediment back into the body of the liquid, so it will stay trapped in the shoulder of the bottle as you pour the clear wine off. It's also the same thing you are doing when you pour the boiling water out of the pot of pasta when it is done cooking, being careful not to tip it so much that the pasta falls into the sink. Which wines need to be decanted? Simple - the ones with gunk floating around in the bottom of the bottle. Hold it up to a light and look. Usually older (10+ years) reds will have developed sediment, and some reds just do it spontaneously. Whites almost never need it. Educated waitstaff and wine salespeople should remember if a particular bottle usually needs it - ask.
To aerate wine is to expose it to oxygen to "open it up" or bring about it's ideal flavor. Interaction with oxygen does make a significant difference in the flavor development of wines - this is one of many factors considered in the age and porosity of barrels, and the time spent therin. If you've ever had a bottle sit for a few days as you nurse another glass with dinner for every night, you may have noticed the "progression" of a wine. This is often a problem when a restaurant opens for dinner after a day closed - the partially used bottle of wine from 3 days ago tastes utterly different than the next newly opened bottle of the exact same vintage. Some wines, particularly tannic, young, robust reds really need a certain amount of aeration to soften them up and bring about their ideal flavor. For this, you want to spread the wine out thinly over a large surface area to expose as much of it to air as possible. Just opening the bottle won't allow enough contact in the few minutes before you drink it.
Which decanter would you use for this purpose?
They will all do more than leaving it in the bottle, but most of it is just aesthetics. A is the simplest, most pragmatic design for the express purpose of putting the greatest surface area in contact with air. B is actually shown overfull - you would want to stop pouring lower, at the widest point. However, if that is what one regular 750 ml bottle looks like in it, it is a poor design. D is a much more old-fashioned design meant more for storage than aeration, and the rest, while perfectly adequate, are mostly shaped like all that for novelty.
Even the act of letting a wine sit in the bottom of your (spacious, wide) glass over dinner, not poured overfull and swirled idly as you hold it and talk aerates a valid amount. Then there are "aerators" - doohickies that force air rapidly into a thin stream of wine to open it up more quickly.
It should be noted that it is entirely possible to aerate a wine too much! There is an ideal amount of oxygen exposure you are aiming for, and it is easy to surpass. If you doubt it, leave a bottle open on your counter for a week. Wines that actually need aeration are robust, tannic, tightly wound reds, such as younger cab, merlot, nebbiolo and petite syrah. Many other reds and even some whites can benefit from it briefly, but a lot of times you will lose other preferred attributes (such as keeping the wine chilled to the preferred temperature) or over-oxygenate and kill it. Older wines tend to be more fragile, especially delicate varietals like Pinot Noir and tempranillo, and some Chiantis and Burgundies. Some very old wines (over 20 years) already must be drunk within 15-20 minutes of opening because they are already so close to the final tipping point. Herin lies the catch - older wines also often have sediment. If you must decant an older red wine to remove sediment, especially if it was never particularly robust or dark in color to begin with, remember that decanting also aerates in the process, and do it just before serving.
So, in conclusion: Generally, younger red wines (under 10 years) that can be described as "bold" "robust" or "tannic," either in the words of the waiter, on the label or by your own examination, will benefit from being aerated. Lots of middle-aged, medium bodied reds and even some whites will also benefit - but that's more a matter of taste. Try aerating part of the bottle and tasting it side by side with the unaerated part. Or taste the first sip, as-is, and then aerate it if you think you might like it softened up a bit. Generally, older (10+), lighter wines are more at risk of being ruined by aeration. Proceed with caution, get the sommolier's opinion, or google's.
A side note: People, including middle-price-point waitstaff, often mistakenly use the word "decant" to mean both "decant" and "aerate." Just remember it's a common mistake and be nice if you correct them. This is, in general, a fairly high-level lesson and an undereducated server might look at you askance if you ask for an unusual wine to be decanted. Just remember - your own taste is your own taste, and you're paying for it, so you're never wrong if you like it that way. Finally, if you aren't sure on a new bottle, don't be afraid to experiment. You don't have to psychically know in one shot. Taste a bit first and request it aerated afterwards if you think it would help. Just be nice enough to tip at least 20% or more if you make them run all over god's green earth to assemble the various equipment for your request.
If I haven't bored you to sleep yet, I hope that was fun!