Losing your bubbles: decarbonation rate of bubbly drinks

When a can or bottle of a carbonated drink is opened, the dissolved CO2 comes out of solution forming gas bubbles. These bubbles are responsible for making these drinks special: the perception of flavour is enhanced by bubbles. Although the diffusion-dominated bubble growth process is well understood for pure fluids, the effect of 'other' solutes is not. Our study investigates how acidity, sweetness, alcohol content influence the rate of bubble growth and bubbling rate of CO2 supersaturated water. Experiments used deionized water with various carbon dioxide partial pressures, ranging from 3.0 bars to 4.0 bars. Synthetic 'soda' and 'beer' samples were prepared using varying concentrations and mixtures of sucrose, citric acid, ethanol, and SDS surfactant. Each carbonated fluid sample was placed in a petri dish and observed via a camera for one hour. The videos were processed to extract data showing the growth of the bubbles as a function of time. The effective diffusion coefficient was inferred by fitting the measurements to the Epstein-Plesset prediction. We found that sweetness is the factor that most significantly impacts the decarbonation rate and the frequency of bubble formation. Tests were also conducted with commercial soda and beer, corroborating the results found with synthetic drinks.