Tiny Bubbles

Brittany Ghiroli at MLB.com conjured a Bronx smellscape last night:

NEW YORK—The scent of champagne floated down the long corridor leading to the Yankees’ clubhouse, wafting through the double doors and straight into a frenzied mosh pit of players, each so soaked that their shirts clung to their back like a second skin. 

“We knew what we had in store for us at home,” Joba Chamberlain said, spewing drips of champagne with every punctuation as he took in the emotions following the Yankees’ 5-2 American League Championship Series-clinching victory over the Angels on Sunday.

Champagne is the celebratory drink par excellence—and the bubbles make it so. A Yankee’s locker room reeking of Riesling wouldn’t be half the fun.

Turns out that bubbles are a key physical factor in delivering the sensory impact of champagne: they literally bring out its characteristic aroma. Or so says a Franco-German research team in a paper published last month in the Proceedings of the National Academy of Sciences. The team was made up of super-intense chemists and oenologists, the kind of nerds who write things like this:

Champagne and sparkling wines are multicomponent hydro-alcoholic solutions supersaturated with CO2-dissolved gas molecules (formed together with ethanol during the fermentation process).

OK, so maybe they’re not the life of the party. But stay out of their way in the lab. Seriously. These guys are the first to apply Fourier Transform Ion Cyclotron Resonance Mass Spectrometry to the fizz of champagne.

Here’s the deal: lots of the aroma molecules in champagne are amphiphilic surfactants, which means that one part of the molecule is hydrophilic and another is hydrophobic. At a fluid-air interface, the hydrophilic end of the molecule dives into the fluid and the hydrophobic part orients to the air. The surface of the champagne in your glass is a fluid-air interface, but so are each of the tiny bubbles rising to the surface. The amphiphilic aroma molecules arrange themselves around the skin of every bubble and ride it to the surface. Once there, the bubble pops and creates a burst of aroma-enriched aerosol (the fizz!). 

At least that was the theory proposed a few years back which the team, lead by a fellow with the outstanding name of Gérard Liger-Belair, has now confirmed. They used ultrahigh-resolution mass spectrometry to compare the organic molecules deep in the wine glass with those in the aerosol fizz just under the drinker’s nose. (Can you imagine how Docteur Gérard Liger-Belair would react to Derek Jeter hosing down Mariano Rivera with a shaken bottle of vintage Veuve Cliquot? He’d probably cry.) 

The research team found 163 molecules (well, technically “exact mass signals”) that were more common in the fizz than in the wine. Among these were molecules traceable to the original grapes and to the yeast cells that transformed them into wine. Also more common in the fizz were molecules known to contribute various toasty, herbaceous, and fruity notes characteristic of champagne. So it seems that bubbles do bring out the flavor.

The chemical analysis was extremely precise, but that doesn’t mean the sensory effects are small. The authors estimate that about 5 liters of CO2 escape from every 750 ml bottle of champagne. Since the average bubble is half a millimeter in diameter we’re talking about 10,000,000 bubbles with a total surface area of 80 square meters. That a lot of aroma-concentrating power per bottle.

Doesn’t that make you thirsty? Here at FirstNerve headquarters we like to sip bubbly while listening to tunes on one of our state-of-the-art 8-track stereo cartridges. À votre santé, Dr. Liger-Belair!