ultrasonic coffee

Australian scientists have developed a method of brewing coffee by
blasting ground beans with sound waves - and it produces a powerful
cup

I'm looking at a coffee that's thick, cold and the deep brown colour
of 90% dark chocolate. It tastes like coffee but, weirdly, without any
bitterness. It is the only coffee I've had that was made by blasting
ground coffee beans with sound. They call it ultrasonic coffee.

It wasn't made by a barista but by two chemical engineers in a lab at
the University of New South Wales in Sydney. Dr Francisco Trujillo, a
senior lecturer in the school of chemical engineering, and the PhD
student Nikunj Naliyadhara explain the coffee they're about to make is
sonicated, or hit with ultrasonic waves. I have no idea what that
means. But they grind coffee beans, pack them into a portafilter
basket (the handled device you've probably seen your barista twist and
untwist) and connect the portafilter to a Breville espresso machine.
And just like your barista, they press some buttons. The machine makes
soft whirring sounds.

Trujillo explains what's happening inside the machine. First, the
coffee is infused in water for five seconds. Then, as the machine
releases room-temperature water on to the coffee grinds a transducer -
a device connected to the portafilter - pushes sound waves through the
basket and into the coffee grinds. He describes an opera singer's
voice making a glass vibrate so intensely it breaks.

https://www.theguardian.com/food/article/2024/may/29/ultrasonic-coffee-australia-scientists-unsw