In a fun experiment, Max Koch, a researcher at the University of Göttingen in Germany—who also happens to be passionate about homebrewing—decided to use a high-speed camera to capture what occurs while opening a swing-top bottle of homebrew.

When Robert Mettin, who leads the Ultrasound and Cavitation group at the university’s Third Institute of Physics, Biophysics, suggested that Koch should submit the findings to the special “kitchen flows” issue of Physics of Fluids, Koch and his colleagues chose to expand on the home experiment and delve into the novel acoustics and physics at play.

The group found that the sound emitted by opening a pressurized bottle with a swing-top lid isn’t a single shockwave, but rather a very quick “ah” sound. Their high-speed video recordings captured condensation within the bottleneck that vibrated up and down in a standing wave.