winemanden
Senior Member
French-American research project solves puzzle
Scientists from the American Brown University and the University of Toulouse have found out why the bubbles in sparkling wine rise in a straight line. In the study, which was published in the journal "Physical Review Fluids", the researchers poured samples of carbonated drinks into the glass. These included mineral water, beer and various sparkling wines that had been produced using the champagne method as well as in a tank. They used a needle to pump gas into the drinks and experimented with bubble size and the addition of surfactants. These are chemicals used to reduce the surface tension of the liquid.
They found that the surfactants already present in sparkling wine and champagne are responsible for the stable, single-row bubble chains, explained Roberto Zenit, lead author of the study and professor of engineering at Brown University: "Impurities in the champagne that act as surfactants are crucial in this. These protein molecules give sparkling wines their flavour and make the bubble chains created stable through wake."
Beer also contains surfactants, but its bubbles often do not rise in a straight line. Sparkling water has no such "impurities" and so there is nothing to guide the bubbles through the wake of other bubbles. Therefore, no vertical chains can form in it.
The researchers can also prove that larger bubbles tend to rise more evenly and also form more stable chains. This contradicts the common view that finer bubbles also means better sparkling wine. "By talking about champagne and beer, we want to make people understand that fluid mechanics is important to their daily lives," Zenit added.
Scientists from the American Brown University and the University of Toulouse have found out why the bubbles in sparkling wine rise in a straight line. In the study, which was published in the journal "Physical Review Fluids", the researchers poured samples of carbonated drinks into the glass. These included mineral water, beer and various sparkling wines that had been produced using the champagne method as well as in a tank. They used a needle to pump gas into the drinks and experimented with bubble size and the addition of surfactants. These are chemicals used to reduce the surface tension of the liquid.
They found that the surfactants already present in sparkling wine and champagne are responsible for the stable, single-row bubble chains, explained Roberto Zenit, lead author of the study and professor of engineering at Brown University: "Impurities in the champagne that act as surfactants are crucial in this. These protein molecules give sparkling wines their flavour and make the bubble chains created stable through wake."
Beer also contains surfactants, but its bubbles often do not rise in a straight line. Sparkling water has no such "impurities" and so there is nothing to guide the bubbles through the wake of other bubbles. Therefore, no vertical chains can form in it.
The researchers can also prove that larger bubbles tend to rise more evenly and also form more stable chains. This contradicts the common view that finer bubbles also means better sparkling wine. "By talking about champagne and beer, we want to make people understand that fluid mechanics is important to their daily lives," Zenit added.
