Sobriety may be in order at the end of the year, but it’s still hard to imagine the holidays without champagne. If everyone has their own technique for opening a bottle, be aware that the uncorking of the precious liquid is the subject of very serious scientific studies. We owe them to Gérard Liger-Belair, professor at the University of Reims Champagne-Ardenne. A specialist in bubbles, this physicist has been studying carbonated drinks and the phenomenon of effervescence for twenty years.
In Champagne, his work quickly led him to phosphorus on champagne and to decipher in particular the role of bubbles which make the charm of the drink. Pressed by questions from journalists, Gérard Liger-Belair also had fun measuring the speed of a popping champagne cork. “We are around 50 to 60 km/h”, he explains. A speed not that high but which can still cause serious damage, physical or material, if the traffic jam goes in the wrong direction.
“Like when a rocket takes off”
While conducting his experiments, the researcher also noticed that a fleeting blue cloud appeared in the neck of the bottle of champagne just after it was opened. “It is the carbon dioxide which is contained in the champagne which is transformed into dry ice crystals”, underlines the physicist. Pushing the envelope a little further, the researcher then asked two colleagues from Rennes Institute of Physics in order to model the images shot during the experiment using an ultrafast camera.
“On many sequences, we systematically saw the appearance of a small horizontal line parallel to the neck of the bottle”, explains Gérard Liger-Belair. Well known in the aeronautical sector, this phenomenon has proven to be a shock wave, the gas escaping from the bottle at supersonic speed within a thousandth of a second following its opening. “It’s like when a rocket takes off, explains Robert Georges of the Institute of Physics in Rennes. At the time of uncorking, the gas escapes from the bottle and comes to smash on the cork which moves away from the bottle. »
Understanding champagne stacking
Delighted with their discovery, the three researchers are no less modest. “We are not revolutionizing anything with this study, believes Gérard Liger-Belair. But it shows that science is hiding behind a whole bunch of small harmless gestures. “We are here on fun physics”, abounds Robert Georges, who sees the bottle of champagne “as a kind of mini-laboratory in which a lot of complex phenomena are happening. »
Not satisfied with bubbles, Gérard Liger-Belair is not done with his work on champagne. The scientist from Reims will now seek to understand the phenomenon of “stacking”. In other words, why does foam spurt out of certain bottles when uncorking them even though they have not been shaken? “It’s a real problem in the sparkling wine industry,” assures our bubble expert.