The quality of a sparkling wine is often linked to the size of its bubbles: and acoustical measurements could provide a way of determining bubble size distribution.
The research is being presented at the 174th Meeting of the Acoustical Society of America this week in New Orleans, Louisiana.
Underwater sound
Investigators Kyle S. Spratt, Kevin M. Lee and Preston S. Wilson from the Applied Research Laboratories at the University of Texas (Austin, US) typically investigate bubbles and underwater acoustics using a hydrophone, which records underwater sound.
A hydrophone listens in to sounds underwater. It works by converting a change in pressure, such as a sound wave, into an electrical voltage.
When they learned of the concept that bubbles are related to the quality of a sparkling wine, they decided to apply their techniques to Champagne.
However, taking measurements proved to be more difficult than expected because bubbles formed on the hydrophone itself, affecting the data obtained. A very small hydrophone was used to combat the problem.
The team also had to consider the properties of the container – investigating bubbles using both a champagne flute and Styrofoam.
"The point of the project is to study the sounds champagne bubbles make, and to see what we can infer about the bubbles from the sounds," said Spratt.
"Bubbles are very resonant. They basically ring like bells, and the frequency of that ringing depends in part on the size of the bubbles.
“There is a well-known notion that the quality of a sparkling wine is correlated to the size of its bubbles, and we are investigating whether the bubble size distribution of a sparkling wine can be obtained from simple acoustical measurements."
The applications of this work could be used for quality assurance testing of sparkling wines, Champagne or even any carbonated beverage. It would have the benefit of highlighting issues that may not be detectable by taste alone.
"The direct application would be as a simple tool that could be used to monitor the bubble size distribution in sparkling wines," Spratt said.