Fun info about champagnes for the nerds among us.
The science of Champagne bubbles up again for New Year's Eve - Cosmic Log
The science of Champagne bubbles up again for New Year's Eve - Cosmic Log
The science of Champagne bubbles up again for New Year's Eve
If you really want to impress your bubbly-sipping friends tonight, be sure to chill a big bottle of Champagne to somewhere between 39 and 50 degrees Fahrenheit (4 to 9 degrees Celsius), bring out the narrow glasses (not those wide plastic cups!) and pour the stuff gently down the angled side of the glass like beer.
This is the scientific way to treat Champagne sparkling wine, based on research conducted over the years by Gerard Liger-Belair, a physicist at the University of Reims in France's Champagne region. His studies on the behavior of bubbly — including high-speed photography of popping bubbles and infrared imaging of carbon dioxide flow — have made him the world's highest-profile expert on Champagne science.
It's a tough job — but somebody's gotta do it.
"I love the beauties behind bubble science," Liger-Belair said in an email. "Since I became a scientist, many people have remarked that I seem to have landed the best job in all of physics, since my research on bubbles requires that I work in a lab stocked with top-notch Champagne — and I'd be inclined to agree."
For Liger-Belair and his colleagues, it's mostly about the bubbles. To be sure, there's much more to sparkling wine than the sparkle: As many as 80 different vintages of wine may be blended together to create one batch of Champagne using the traditional process. A small amount of yeast and sugar is added, and the bottles are sealed up for fermentation. Months later, the yeast sediment is blown out through the bottle's neck — and then the bottle is quickly corked up and wired shut.
Liger-Belair's research focuses on what happens next, when the cork is popped off. The CO2 that was created through the fermentation process bubbles out of the wine — tickling the nose with a fizzy aerosol of alcohol and flavorful ingredients known as volatile organic compounds. The more CO2 that can be liberated after the champagne is poured into the glass, the better.
That's where science comes into play. Liger-Belair and his colleagues recently reported that larger bottles of Champagne retain more CO2 in the wine as it's being poured into the glasses. So if you have a choice between several small bottles and fewer big bottles, go for the big ones. But be sure those bottles are well-chilled: Warm champagne loses its CO2 quickly as it's being poured, leaving less to fizz up out of the glass.
Speaking of the glass: Liger-Belair's team determined that tall, narrow-rimmed flutes produce a better effect than the wide-rimmed "coupes" that folks more typically associate with sparkling wine. That's because the CO2 rises out of a wide-rimmed glass too quickly, over a wider surface area. Also, glass flutes are better than plastic cups, and not just for aesthetic reasons: The plastic material is hydrophobic — that is, liquid-repellent — which means the bubbles are more likely to adhere to the sides of the cup and less likely to contribute to a nice fizz.
If you really want to get your fizz on, wash your glasses before the party and dry them with a towel rather than letting them air-dry: The microscopic fibers of cellulose that are left inside the glass actually contribute to bubble production. Some glass-makers add tiny scratches to their Champagne glasses to create pleasing patterns of bubbles, and you can feel free to experiment with the same technique. (Just not with the expensive glassware.)
When it comes to the pouring, don't splash the Champagne straight down into the bottom of the glass. Instead, trickle it down the side, like beer. That preserves more of the carbon dioxide for the bubbles that rise while you're drinking the wine. "The beer-like way of serving champagne much less impacts its dissolved CO2 concentration than the Champagne-like way of serving it, and especially at low Champagne temperatures (4 degrees C and 12 degrees C)," Liger-Belair reported.
Liger-Belair has laid out many more findings about Champagne in a decade's worth of research papers — and in his book, "Uncorked: The Science of Champagne," which is being updated with the latest revelations for a new edition. One of his recent papers, an 88-page survey written for the European Physical Journal, is available for free download today.
Here's a sampling of sparkling facts:
- There are six bottles' worth of gaseous CO2 packed into every bottle of Champagne.
- A significant amount of that CO2 leaks out of the bottle through the cork. Liger-Belair's study of Champagne bottled in the 1990s suggested that almost a third of the CO2 could be lost over the course of 15 years. "Because the size of bubbles is linked with the level of dissolved CO2 in Champagne, bubbles get thinner over time when Champagne ages," Liger-Belair said.
- The higher the wine's temperature, the bigger the "pop" when the cork is released. That's because the CO2 pressure increases with temperature. Some folks might keep their Champagne warm to maximize the pop, but be careful: A popped cork can travel as fast as 50 mph (80 kilometers per hour). Every year, the American Academy of Opthalmology warns that sparkling-wine corks rank among the top holiday-related eye hazards — and provides tips for proper cork removal.
- Only 5 percent of the pop goes toward the cork's kinetic energy. Most of the rest goes toward generating the popping sound's shock wave. The pattern of CO2 that's set loose when the cork is popped is similar to the mushroom cloud created by an exploding atom bomb.
- If you see a white wisp of mist rising from a just-popped bottle, that's not carbon dioxide. That's a fog of ethanol and water vapor, triggered by the sudden drop in gas temperature when the pressure is released. (That's what's known as adiabatic expansion.)
It might seem frivolous to devote so much attention to the physics of fizz, but Liger-Belair said his research is about much more than your single bottle of bubbly on New Year's Eve.
"In fact, bubbles are a fantastic example of bubble dynamics in general, and studies dealing with champagne bubbles can be extended to many other areas where bubbles play a role, in natural as well as industrial processes. For example, marine aerosols created by bursting bubbles behave like champagne's bursting bubbles. ... The scales are different, but the basic principles are identical," he said in his email.
Liger-Belair's research at the University of Reims is generally funded by enological and agricultural programs in France and Europe — such as L'Association Recherche Oenologique Champagne et Université, which was created to boost the Champagne region's best-known industry.
"As far as champagne is concerned, 350 million bottles sold per year all over the world deserve particular attention. The job may seem fun indeed, as any job made with passion should be," Liger-Belair said. "I am aware that devoting so much energy to studying champagne bubbles may seem 'weird,' but the implications of bubble dynamics are universal."
So just before you take a sip of cool, sparkling beverage from your towel-dried flute, raise a toast to Liger-Belair ... and the science of champagne.
Update for 12:45 p.m. ET: Legend has it that the wide-rimmed, bowl-like champagne coupe was modeled after the breast of Marie Antoinette (or the Empress Josephine, or Helen of Troy ...), but Snopes.com says there's no truth to the legend.
