University Team Develops Room-Temperature Ultrasonic Espresso Process

A research team at the University of New South Wales in Australia has developed a room-temperature brewing process that uses high-frequency sound waves to extract flavor, oils, aroma, and caffeine from ground coffee. ” The experimental system directs ultrasonic waves into a filter basket holding ground beans and water.

Researchers designed a device that transmits vibrations throughout the basket, turning it into an acoustic reactor that produces microcurrents through acoustic cavitation.

The ultrasonic process takes three minutes, compared with 30 seconds for conventional espresso, yet consumes 75 percent less energy. Using a fine grind and 100 watts of power, the team achieved dissolved solids and extraction yields that meet Specialty Coffee Association standards; the same conditions without ultrasound did not reach those values. 5 and 3 minutes.

Caffeine and chlorogenic acid concentrations matched those from conventional espresso, and no significant differences appeared in pH or overall volatile compound composition. A group of 100 people participated in sensory tests comparing ultrasonic espresso with conventional espresso. Participants showed no notable preference between the two for aroma, flavor, bitterness, or overall acceptance.

For filtered coffee, participants generally preferred the ultrasonically processed version and rated its bitterness as more pleasant. The ultrasonic system used 24 percent of the energy consumed by a typical espresso machine to produce beverages of the same intensity. ” The research is described in the June 2026 issue of the Journal of Food Engineering.

The authors note that coffee produced with ultrasound is not identical to traditional espresso but can achieve comparable chemical and sensory characteristics without heating the water.