Sometimes scientists deserve a toast to their research. We are talking about physicists from Brown University in the USA, who in this particular case could hardly do without cooperation with specialists from France. Together with colleagues from the University of Toulouse, the flow research experts also succeeded in tracing the typical path of the bubbles in a champagne goblet and in finding out why they do not bobble back and forth in the glass, but mostly take the direct route to the surface.
One could almost speak of a “signature move” of bubbles in champagne, prosecco and other sparkling wines. Lined up like a string of pearls, they rise linearly as the bubbles in beer, soda, or other carbonated beverages move in all possible directions before escaping the beverage. The physicists, who published their results in the journal, speak of a “stable chain of bubbles”. Physical Review Fluids have published. They also assure that they did not drink all of the test liquids, but mostly discarded them.
The scientists attribute the typical arrangement of bubbles in champagne to a so-called surfactant factor, i.e. to surface-active substances (surface acting agents). Similar to soap, such molecules reduce the surface tension of bubbles, which reduces the tension between the gas inclusions and the liquid surrounding them. In this way, a smooth ascent is possible, the bubbles stay on track. “We suspect it’s the good stuff in champagne that reduces surface tension and leads to the stable bubble chain,” says Roberto Zenit, who was involved in the study. “In other words, exactly those flavorings that make the enjoyment so unique.”
In beer there are sometimes bubbles that rise up in an orderly fashion directly to the surface, but this is not the case for all types, but depends on whether the ingredients have a surfactant effect. The bubbles in mineral water, on the other hand, are never stable, but wander around in the liquid. There are simply no other components in the drink that could affect the surface tension.
The researchers emphasize that their everyday investigations are not the result of a champagne mood. In medicine, a specific surfactant factor plays an important role in the development of babies’ lungs; the lack of this substance can cause severe breathing problems in premature babies. In industry, gases are specifically pumped into liquids because they mix better through the formation of bubbles. The flow mechanics of bubbles is also of great importance for the preparation of drinking water.
The scientists are pleased that some of their observations can be reproduced in the corner pub or at home – and in this way it is also recognized in passing how important the behavior of liquids and research with the Blubb is. Hardly anyone has seen an ocean sink, a DNA analysis or the control module of a space shuttle up close, “but most people have had a glass of soda, beer or champagne in their hands,” says Zenit. Well then cheers!