Tiny Bubbles At The NYAS
Ah, champagne. The sparkly, bubbly, goodness is my favorite summertime drink. It’s not so bad for toasting special occasions, either. Or as an aperitif before a large meal. Or mixed with orange juice at brunch. Okay, let’s be honest, I would pretty much drink it at breakfast, lunch, and dinner, if it was acceptable (and I was in a different tax bracket).
Needless to say, I was pretty excited to see that the New York Academy of Sciences was bringing Gérard Liger-Belair, a professor of chemical physics at the University of Reims Champagne-Ardenne, to New York City to talk about the science of champagne. Liger-Belair has spent the past 10 years studying those tiny, wonderful champagne bubbles. Using high-speed photography, microscopy, and lasers, he’s managed to pin down all you’d ever want to know about how every bubble in your glass is born, grows, and bursts.
Some fun facts from Liger-Belair’s talk:
*Effervescence is promoted by cellulose fibers stuck to the wall of your glass. Yes, dust is the source of that sparkly goodness. In fact, champagne poured into a perfectly clean glass has no bubbles. Champagne poured into a plastic cup has big bubbles that are stuck on the wall of the cup, because the hydrophobic plastic prefers the contact of the gas to the liquid.
*The best way to wash your champagne flute is with hot water (no soap), then wipe it down with a towel to leave behind some fibers to promote that effervescence.
*The main parameters for the rate of bubble formation are temperature (the higher the temperature, the higher the bubbling rate) and viscosity (the bubbling rate is inversely proportional to the viscosity, which is itself related to the sugar content—in other words, a very sweet champagne will have a lower bubbling rate.).
*Bubbles grow bigger and accelerate as they rise up the side of the flute. The main parameters influencing bubble growth are the distance traveled (you get bigger bubbles in longer flutes), the concentration of the dissolved CO2, and gravity acceleration . (Liger-Belair seems keen on the idea of astronauts drinking champagne on their next trip to the moon.)
*Each bursting bubble produces about five tiny droplets at the surface, creating that wonderfully, sparkly cloud that tickles your nose when drinking champagne.
*And for you beer aficionados, it seems that the CO2 concentration is twice as high in champagne than in beer; in other words, the bubbles are just bigger (um, about twice as big) in champagne.
For more information on how champagne is made, check out Bethany Halford’s What’s That Stuff on the topic. And Liger-Belair has written an entire book on bubbles, “Uncorked: The Science of Champagne,” that includes some of his amazing photography.