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Espresso machines work fast: you can go from a puck of ground coffee to a delicious shot in 30 seconds. But they also use a lot of energy, mostly because they heat water to pull shots—they’re often a coffee shop’s most energy-intensive appliance. What if there were a more efficient way to achieve similarly tasty results?
A team of Australian researchers says they have done just that, using ultrasonic soundwaves to brew espresso-strength coffee from room-temperature water. They claim the new process reduces energy consumption during brewing by 75% compared to a regular espresso machine.
There is a trade-off, however: using ultrasonic waves takes 2-3 minutes, which any math whiz will tell you is significantly longer than 30 seconds.
The new method is based on a previous experiment conducted in 2024, in which the researchers used sound waves to accelerate the cold-brewing process. The team retrofitted an espresso machine with a device called a “sonic horn” attached to the portafilter. The device sends ultrasonic waves through the portafilter, creating something called “acoustic cavitation,” which causes the rapid formation and collapse of microscopic bubbles near the coffee particles. This process creates a reaction that speeds up extraction.
A group of 100 coffee drinkers was unable to distinguish between espresso shots pulled the old-fashioned way versus those brewed using ultrasonic waves. “These findings showed 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,” co-author Francisco Trujillo said in a press release.
While it can’t compete with a commercial espresso machine for speed, Trujillo hopes that their creation can be used by companies that brew coffee at scale. “Because the process produces a concentrated, espresso-strength coffee, it can be used directly to manufacture ready-to-drink products, or shipped as a concentrate and later diluted into a range of drinks, including cold brew and milk-based coffee drinks,” he said.
Read more on ultrasonic espresso from Popular Science here.
Photo by Pawel Czerwinski on Unsplash
