It's almost New Year's Eve and that means that people all over the world will be popping open a bottle of the bubbly.
Champagne is a staple of celebrations everywhere, thanks to its unique fizz and bubbles. But what creates those bubbles in the first place?
That's what scientists with the American Chemical Society (ACS) decided to find out. Although we've long known that carbon dioxide plays a large part in the bubbly process, ethanol helps the bubbles diffuse properly after you open a bottle.
So why study champagne's bubbles? Basically, the ACS wanted to show that using molecular dynamics simulations is just as effective as using other more complicated measurement methods, including nuclear magnetic resonance (NMR) and viscometry in studying liquids. They also wanted to know if temperature affected the kinetics of carbon dioxide.
Previous research shows that two things happen when a bottle of champagne emits carbon dioxide bubbles. Because these beverages have high amounts of carbon dioxide, this emission happens between the surface of the liquid and a gas phase, in this case, the air above the glass.
Secondly, effervescence plays a part. This is when bubbles form from gas pockets trapped within particles, such as scratches or etchings on the glass surface. When a gas pocket gets to a certain size, carbon dioxide mixes with that gas pocket, which makes the bubbles bigger. As this happens, the champagne releases many bubbles at once.
Using this knowledge, researchers studied how the carbon dioxide and ethanol molecules in champagne work to make this happen. Instead of using traditional measurements, though, they used simulations. Their simulations were in line with what traditional measurement methods show: carbon dioxide diffuses faster at higher temperatures.
When carbon dioxide diffuses, the number of carbon dioxide molecules is greater than that of the ethanol molecules. This happens because ethanol bonds with the hydrogen in the water that exists in champagne. Because of this, carbon dioxide becomes its own separate entity and reacts by floating to the top of the glass. This also suggests that bubbles have no effect on a champagne's taste.
The idea is that the simulation technique in studying champagne is easily applied to other liquids.
"Although Champagne is a multicomponent liquid by nature (that is, composed of a number of different molecules), CO2 diffusion can be simply modeled by applying methods commonly used for binary mixtures," says David A. Bonhommeau from the University of Reims Champagne-Ardenne. "Such an approach could be extended to the investigation of the diffusion of small molecules in other supersaturated liquids such as brines (i.e., water in oceans) or maybe in amorphous solids (molecules trapped in ice for atmospheric or astrochemical applications)."
[Photo Credit: Free Images]
