ITHACA, N.Y. — A bubble bath with a constant acoustic sound in water may be the best chemical-free, gentle method for cleaning agricultural produce, according to new research published March 25 in the journal Droplet.

Agricultural produce is currently cleaned by washing with bubblers for greens or soft brushes for root crops to clean off sediments. Chlorine, ozone and peroxyacetic acid are often added to the water as sanitizers.

The new technique places vegetables in a bath with a bubbler, and then adds a constant acoustic drone at a low frequency with an underwater speaker. The sound creates resonance in bubbles that causes them to vibrate. Vegetables were 90% cleaner when washed with the resonating bubbles, as compared with bubbles without any sound waves or at frequencies that didn’t lead to resonance, according to the study.

“There are few options for cleaning soft surfaces,” said Sunny Jung, professor of biological and environmental engineering in the College of Agriculture and Life Sciences at Cornell University and the study’s senior author.

Yany Lin ’26, a biological sciences and philosophy double-major in the Cornell University College of Arts and Sciences and a member of Jung’s lab, is the paper’s first author.