Hello there! I'm Dr. Vinifera, but you can call me Vinny. Ask me your toughest wine questions, from the fine points of etiquette to the science of winemaking. And don't worry, I'm no wine snob—you can also ask me those "dumb questions" you're too embarrased to ask your wine geek friends! I hope you find my answers educational, empowering and even amusing. And don't forget to check out my most asked questions and my full archives for all my Q&A classics.
Dear Dr. Vinny,
What is the science behind the aeration of wine? What does air do to a wine? Why is it if a wine is closed and then you put air though it (via a funnel of some type) that it can release the aromas and flavors of the wine?
Do you have any scientific research to support your claims about the supposed benefits of aerating bottled wine? Anecdotes and tasting notes are not research.
—Ken B., Fairdale, Ky.
The problem is that the results that you’d like to measure are how a wine tastes and smells, and there’s no good way to assess that except anecdotally, via sensory analysis and things like tasting notes. I even checked with wine professors and folks who actually wear white lab coats, and they all said the same thing.
If you’ll allow a common-sense and anecdotal answer, we know that exposing wine to air does two things: trigger oxidation and evaporation. Since these things happen on the surface of a wine, the more surface area the wine has, the more they happen. So, opening a bottle will give you some effect, but putting the wine through a decanter or funnel or pouring it in a glass and swirling it around will be more effective.
From what we can tell, the aeration process helps release the wine’s volatile components—especially the stinky ones, like sulfur compounds and ethanol. While these notes fade into the background, the more desirable, aromatic and flavorful compounds come to the forefront. Often, the wine becomes more expressive.
The mix of oxygen starts to oxidize the phenolics and tannins, which at first can make the wine softer. Unfortunately, after a while all that oxygen causes the wine to oxidize, and it will flatten out and become less expressive. Younger, more concentrated wines have a longer time before they start to fade, while older wines are more delicate and fade faster.
While I really do appreciate the desire to measure and quantify all the many variables in wine, in this case there isn’t much evidence beyond millions of wine drinkers experiencing how aeration affects wine every single day.