"Explosive" bottled beer phenomenon explained
24 Nov 2013
European scientists have produced fresh insight into the science behind rapidly foaming beer bottles by exploring the process of cavitation.
Lead researcher Javier Rodriguez-Rodriguez explained that cavitation, a phenomenon relevant to common engineering concerns such as the erosion of ship propellers, is the mechanism by which bubbles appear in a liquid after an impact.
“We wanted to explain the extremely high efficiency of the degasification process that occurs in a beer bottle within the first few seconds after the impact,” Rodriguez-Rodriguez said.
“Buoyancy leads to the formation of bubbles, whose shape resembles the mushrooms seen after powerful explosions
Javier Rodriguez-Rodriguez
The investigation of beer bottle-fluid interactions demonstrated that the cavitation-induced break-up of larger “mother” bubbles created clouds of small carbonic gas “daughter bubbles” - which grow and expand much faster than the larger mother-bubbles from which they split, according to researchers.
They explained that the rapid expansion of these daughter bubbles gives the foam its buoyancy.
“Buoyancy leads to the formation of plumes full of bubbles, whose shape resembles very much the mushrooms seen after powerful explosions.
“And here is what really makes the formation of foam so explosive: the larger the bubbles get, the faster they rise and the other way around,” Rodriguez-Rodriguez said.
The team’s work is said to be the first quantitative analysis of the beer bottle foamover but can also be applied to other engineering systems and serious natural phenomena such as the sudden release of dissolved carbon dioxide.
