A research team at UNSW Sydney says it has brewed espresso‑strength coffee at room temperature in under three minutes using high‑frequency ultrasound, cutting energy use by up to 75% compared with a conventional machine. The work, led by Senior Lecturer Dr. Francisco Trujillo in the School of Chemical Engineering, was published on 1 June 2026 in the Journal of Food Engineering, according to the university’s newsroom report and coverage in Daily Coffee News.
In controlled tests, the ultrasonic system consumed 0.020 kilowatt‑hours of electricity over 20 minutes to prepare three espresso‑strength beverages, compared with 0.0823 kilowatt‑hours for a single‑group traditional espresso machine producing drinks of similar strength, around 8.7–8.9% total dissolved solids (TDS), Daily Coffee News reported. The researchers describe this as an energy reduction of up to 75%, a figure repeated in both the UNSW announcement and a June 10 analysis in The Conversation.
“Traditionally, espresso is by forcing hot water through coffee under pressure. But with ultrasound we can use room‑temperature water instead, reducing energy consumption by up to 75%,” Dr. Trujillo said in comments published by the UNSW newsroom and Daily Coffee News. He added that “it’s a different process, but you get the same richness and concentration of a normal espresso in under three minutes,” according to UNSW and a June 11 article in Popular Science.
Sensory testing suggests the room‑temperature method may not require a trade‑off in flavor. In blind tastings with 100 coffee drinkers, participants “could not consistently differentiate between traditional and ultrasonic espressos,” the UNSW newsroom and Popular Science reported. Summarizing these results, Dr. Trujillo stated that “using ultrasound did not harm taste, and in some cases even improved it, despite brewing at room temperature and without the heat normally associated with coffee making,” according to UNSW and industry outlet Food Processing.
The team also examined filter‑style preparations. An article in The Conversation noted that, for filter coffee, study participants preferred the ultrasound‑brewed version overall and rated its bitterness more pleasantly than the control. The same article and Popular Science both reported that the “sweet spot” for the ultrasonic process was between 2.5 and 3 minutes of application.
From an extraction standpoint, the ultrasonic setup increased efficiency at finer grind sizes. At the finest grind tested, around 325 microns, ultrasound‑assisted brewing reached an extraction yield of 18.03% compared with 16.26% without ultrasound, entering the Specialty Coffee Association’s cited optimal range of 18–22% extraction yield, according to Daily Coffee News. The outlet reported that the system used a transducer vibrating at 38.8 kilohertz to generate acoustic cavitation, a mechanism that UNSW’s earlier 2024 cold‑brew research said creates micro‑jets that fracture coffee grounds.
UNSW’s newsroom described traditional espresso preparation as highly energy‑intensive, largely because of the need to heat water to near‑boiling under pressure, and stated that reducing this energy “is of substantial value to the global ready‑to‑drink (RTD) coffee beverage industry.” In the same announcement and in Daily Coffee News, Dr. Trujillo said “there are companies that make coffee products on an industrial scale and we are confident this ultrasound system can be scaled up to meet their needs, delivering real benefits in terms of reduced processing times and energy use.”
The ultrasonic brewing work builds on a 2024 project in which the UNSW team applied similar technology to cold brew. That earlier system doubled extraction yield and caffeine concentration and increased coffee oil extraction eightfold, according to an article from Engineers Australia. The same piece noted that Global Coffee Report had described the invention as “the future of brewing,” while Barista Magazine called it “a game changer in cold brew.”
The new room‑temperature espresso process is linked to a pending international patent application, WO2025/118023A1, assigned to UNSW, Daily Coffee News reported. According to the UNSW newsroom, the research team aims to license or scale the patented ultrasound system for commercial ready‑to‑drink beverage manufacturers to process coffee on an industrial scale.
