The mystery of why bubbles in champagne rise straight up has finally been cracked by researchers. In sparkling wines like champagne, gas bubbles appear continuously and rise quickly in a single file.
Experts say this is known as a stable bubble chain and it occurs when ingredients act as soap-like compounds known as surfactants.
Tension between the liquid and the gas bubbles is reduced, making for a smoother rise to the surface. In other carbonated drinks, many bubbles veer off to the side, making it look like multiple bubbles are rising at once, meaning the chain is not stable.
Researchers from Brown University in the US and Toulouse University in France – the home of champagne – set up their study to investigate the stability of bubble chains in carbonated drinks.
They carried out a series of experiments, including pouring out glasses of champagne, beer, sparkling water and sparkling wine.
Researchers said the results may hold important implications for understanding bubbly flows in the field of fluid mechanics. Senior study author and engineering professor at Brown University Roberto Zenit said: “Most people have never seen an ocean seep or an aeration tank but most have had a soda, a beer or a glass of champagne.
“Our plan is to make people understand that fluid mechanics is important in their daily lives.”
The researchers said the stability of bubbles is affected by their size. They found that chains with large bubbles have a wake similar to that of bubbles with contaminants, leading to a smooth rise and stable chains.
However, in drinks these bubbles are always small, making surfactants the key ingredient to producing straight and stable chains. The results provide a general framework in fluid mechanics for understanding the formation of clusters in bubbly flows.
Experts say understanding these flows may help better explain methane and carbon dioxide emerging from the bottom of the ocean.