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Scientists from Brown University in the US and the University of Toulouse have discovered 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 glasses. These included mineral water, beer and various sparkling wines produced using the champagne method and in tanks. Using a needle, they pumped gas into the drinks and experimented with the bubble size and the addition of surfactants. These are chemicals used to reduce the surface tension of the liquid.
They discovered 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. These protein molecules give sparkling wines their flavour and make the chains of bubbles produced stable through wake."
Although beer also contains surfactants, its bubbles often do not rise in a straight line. Sparkling water has no such "impurities" and therefore 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 generally rise more evenly and also form more stable chains. This contradicts the common belief that finer bubbles also means better sparkling wine. "By talking about champagne and beer, we want to make people realise that fluid mechanics is important for their daily lives," added Zenit.
(uka / Source: Drinks Business)