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Fluid mechanics researchers found that surfactants give the celebratory drink its stable and signature straight rise of bubbles [brown.edu]:

Here are some scientific findings worthy of a toast: Researchers from Brown University and the University of Toulouse in France have explained why bubbles in Champagne fizz up in a straight line while bubbles in other carbonated drinks, like beer or soda, don't.

The findings, described in a new Physical Review Fluids study [aps.org], are based on a series of numerical and physical experiments, including, of course, pouring out glasses of Champagne, beer, sparkling water and sparkling wine. The results not only explain what gives Champagne its line of bubbles but may hold important implications for understanding bubbly flows in the field of fluid mechanics.

"This is the type of research that I've been working out for years," said Brown engineering professor Roberto Zenit, who was one of the paper's authors. "Most people have never seen an ocean seep or an aeration tank but most of them have had a soda, a beer or a glass of Champagne. By talking about Champagne and beer, our master plan is to make people understand that fluid mechanics is important in their daily lives."

[...] When it comes to Champagne and sparkling wine, for instance, the gas bubbles that continuously appear rise rapidly to the top in a single-file line and keep doing so for some time. This is known as a stable bubble chain. With other carbonated drinks, like beer, many bubbles veer off to the side, making it look like multiple bubbles are coming up at once. This means the bubble chain isn't stable.

[...] The results of their experiments indicate that the stable bubble chains in Champagne and other sparkling wines occur due to ingredients that act as soap-like compounds called surfactants. These surfactant-like molecules help reduce the tensions between the liquid and the gas bubbles, making for a smooth rise to the top.

"The theory is that in Champagne these contaminants that act as surfactants are the good stuff," said Zenit, senior author on the paper. "These protein molecules that give flavor and uniqueness to the liquid are what makes the bubbles chains they produce stable."

The experiments also showed the stability of bubbles is impacted by the size of the bubbles themselves. They found that the chains with large bubbles have a wake similar to that of bubbles with contaminants, leading to a smooth rise and stable chains.

[...] The results in the new study go well beyond understanding the science that goes into celebratory toasts, the researchers said. The findings provide a general framework in fluid mechanics for understanding the formation of clusters in bubbly flows, which have economic and societal value.

Technologies that use bubble-induced mixing, like aeration tanks at water treatment facilities, for instance, would benefit greatly from researchers having a clearer understanding of how bubbles cluster, their origins and how to predict their appearance. In nature, understanding these flows may help better explain ocean seeps in which methane and carbon dioxide emerges from the bottom of the ocean.

Journal Reference:
Omer Atasi, Mithun Ravisankar, Dominique Legendre, and Roberto Zenit, Presence of surfactants controls the stability of bubble chains in carbonated drinks, Phys. Rev. Fluids 8, 053601 DOI: 10.1103/PhysRevFluids.8.053601 [doi.org]

Original Submission