Ultrasonic Waves Used to Brew Espresso Without Hot Water, Study Says
10 reported
A research team led by Colombian scientist Francisco Trujillo at Australia’s University of New South Wales has developed a method for brewing espresso using ultrasonic waves instead of hot water. The process, described as “ultrasonic espresso,” uses high-frequency sound waves at room temperature to extract flavor, oils, aroma, and caffeine from ground coffee. While the ultrasonic method takes three minutes compared to 30 seconds for conventional espresso, it consumes 75 percent less energy. The findings were published in this month’s issue of the Journal of Food Engineering. Sensory tests involving 100 participants found no notable preference between ultrasonic and conventional espresso in terms of aroma, flavor, bitterness, and overall acceptance. The researchers note that the coffee produced is not identical to traditional espresso but has comparable chemical and sensory characteristics.
What’s reported
The ultrasonic brewing process uses high-frequency sound waves at room temperature to extract coffee compounds.
The method takes three minutes versus 30 seconds for conventional espresso.
It consumes 75 percent less energy than a typical espresso machine.
Using a fine grind and 100 watts of power, the beverages achieved dissolved solids and extraction yields considered ideal by the Specialty Coffee Association.
Experiments without ultrasound under the same conditions did not achieve these values.
Concentrations of caffeine and chlorogenic acid were similar to conventional methods.
No significant differences were observed in pH or volatile compounds responsible for aroma.
In sensory tests with 100 people, participants showed no notable preference for either method.
For filtered coffee, the ultrasonically processed version was generally preferred, with bitterness rated as more pleasant.
The ultrasonic system used just 24 percent of the energy consumed by a typical espresso machine to produce beverages of the same intensity.
Key figures
Francisco Trujillo: Colombian researcher, led the team at Australia’s University of New South Wales.
Sources: Wired
