Can Champagne ‘bubble acoustics’ be used to measure wine quality?

You may be able to taste the difference between a good and a bad wine, but scientists at the University of Texas have suggested you may be able to hear the difference too.

According to a release published in Science Daily, scientists are examining whether the sound of Champagne bubbles forming can be a measurement of a wine’s quality. Both the number and size of the bubbles in a fizz are already established quality indicators, with oenophiles regularly extolling the virtues of a fine mousse. In contrast, large, infrequent bubbles are considered undesirable.

Scientists Kyle S Spratt, Kevin M. Lee and Preston S. Wilson from the Applied Research Laboratories at the University of Texas wanted to examine what can be determined by the sound of Champagne bubbles. They are due to present their findings during the 174th Meeting of the Acoustical Society of America, taking place this week.

Commenting on the project, Spratt said: “The point of the project is to study the sounds that Champagne bubbles make, and to see what we can infer about the bubbles from the sounds that they make. 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 team measured the Champagne acoustics using a hydrophone, an instrument used to record sound underwater. However, when used in carbonated drinks, the sounds recorded by the hydrophone become distorted, as bubbles form on the device itself. To stop this from happening, the scientists used “a very small hydrophone”.

They also found that the type of vessel used to hold the Champagne also impacted on the results.

Maggie Henriquez, CEO and president of Krug, recently told members of the drinks media in Hong Kong that drinking Champagne out of a flute was akin to going to a music concert and wearing ear plugs. The Krug Champagne was instead served up in tulip glasses which are believed to retain the aromas of a wine better than those with ‘straight sides.’

It is also thought that the design of a glass influences the formation of bubbles, with coupe glasses, due to their width and lack of depth, causing a cluster of bubbles to congregate on the surface and in the centre of the glass. Taller, narrower glasses, such as the flute or tulip glass, cause a more even distribution of bubbles.

In this experiment, however, the material – rather than the shape – of the vessel was examined.

Spratt continued: “A wine glass is also a resonant object, so another challenge for us was to make sure that the characteristics of the glass itself weren’t biasing our measurements in some way”.

In order to avoid this, the team took readings from Champagne housed in different containers, including one made of styrofoam.

“It turns out the bubble formation process on styrofoam is completely different than on glass. So, if you ever have to resort to drinking champagne out of a styrofoam cup, the bubbles will be quite different,” Spratt revealed.

The team believe that their findings could prove useful in quality assurance tests of sparkling wines as well as other carbonated drinks. They have said that there is a possibility that measuring the sound of the bubbles could flag up potential faults or issues that are not 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 added.

In a recent study, that has been met with scepticism from many in the trade, cork and screwcaps were pitted against each other to find out whether the pop of a cork affects our perception of wine quality. The results of the experiment found that wines bottled under cork are perceived to be 15% better quality than those closed with a screwcap.