Dry ice can briefly shoot out of a Champagne bottle at nearly twice the speed of sound, or about 2,400km per hour, according to new research published in the Science Advances journal.
While this velocity was only reached for a millisecond and came after storing bottles above the ideal serving temperature, one scientist involved said it was a ‘huge surprise’.
Researchers had set out to capture a Champagne cork popping using high-speed video and six bottles of rosé Champagne from Vranken-Pommery Monopole.
They hoped to better understand how temperature and associated air pressure changes influence the way carbon dioxide (CO2) in the bottle reacts with the air outside once released.
It is already known that storing Champagne at higher temperatures increases the pressure in the bottle versus the air outside.
This can cause CO2 to freeze and turn to dry ice when suddenly released, creating a plume at the bottle opening. Bottles stored at 20 degrees Celsius ejected a freezing jet of CO2 at nearly -90 degrees Celsius in the latest study.
‘The huge surprise deserving an article in Science Advances was the formation of a Mach disk [in the jet of freezing CO2], similar to what is happening with rocket plume exhausts,’ said Gérard Liger-Belair, one of the researchers and who is professor of chemical physics at the University of Reims Champagne-Ardenne.
‘The conditions needed to create such shock waves are drastic, but in the very first millisecond following cork popping, all the conditions are met,’ he told Decanter.com.
‘The velocity of gases expelled from the bottleneck reaches almost Mach 2, twice the velocity of sound.’
However, the experiments were carried out on Champagne bottles stored at 20 and 30 degrees Celsius for 72 hours before filming – well above what would be considered the ideal serving temperature.
A bottle chilled and opened at between eight and 10 degrees Celsius ‘is not enough to produce such a transverse shockwave’, Liger-Belair said, unless the bottle was opened at high altitude with a lower outside air pressure.
Still, he said the filming experiment showed that ‘there is a lot of wonderful and subtle science hidden in a single bottle of Champagne’.
See the Science Advances journal article here
See also: How to pair Champagne with food