- Researchers at UNSW Sydney demonstrated a brewing technique that replaces hot water with sound waves.
The team built a prototype that directs high‑frequency ultrasonic pulses through room‑temperature water, extracting coffee solubles to produce a drink comparable to espresso. In blind tests with 100 participants, none could reliably tell the ultrasonic brew from a traditional hot‑water extraction. The method consumes roughly 25% of the power needed for conventional espresso machines, according to the authors' measurements.
If the approach scales, coffee shops could lower their electricity bills and reduce the heat load on kitchen ventilation. The same principle might apply to other hot‑water processes, from tea to certain industrial extractions.
For now it remains a lab demo, but the energy claim is hard to ignore.