Researchers at the University of New South Wales (UNSW) have unveiled a new method of making espresso that could dramatically reduce energy consumption. The technique uses ultrasonic sound waves and room-temperature water to produce espresso-strength coffee in under three minutes, eliminating the need for the hot water traditionally required in espresso brewing. 

The team developed an ultrasonic reactor that uses high-frequency vibrations to extract flavour compounds, oils, and caffeine from coffee grounds. The process cuts energy use by up to 75 per cent compared with conventional espresso machines.