Science behind bottled beer bubbling over when tapped revealed

Researchers have claimed to have understood the reason as to why bottled beer bubbles over when it's tapped.

Now researchers from Carlos III University in Madrid, Spain and Universite Pierre et Marie Curie, Institut Jean le Rond d'Alembert, France, have produced new insight into the science behind foaming beer bottles by exploring the phenomenon of cavitation.

Javier Rodriguez-Rodriguez, the lead researcher from Carlos III University Cavitation, said that a phenomenon relevant to such common engineering concerns as erosion of ship propellers, is the mechanism by which bubbles appear in a liquid such as beer after an impact.

After a sudden impact against a bottle's mouth, back and forth movement of compression and expansion waves will cause bubbles to appear and quickly collapse.

The team's investigation of beer bottle-fluid interactions demonstrated that the cavitation-induced break-up of larger "mother" bubbles creates clouds of very small carbonic gas "daughter bubbles," which grow and expand much faster than the larger mother-bubbles from which they split.

The rapid expansion of these daughter bubbles gives the foam buoyancy.

Rodriguez-Rodriguez said that buoyancy leads to the formation of plumes full of bubbles, whose shape resembles very much the mushrooms seen after powerful explosions.

He added that this happens because fast-moving bubbles entrain more carbonic gas.