Researchers have unveiled a new way to make espresso that skips the usual heating step. By using ultrasound at room temperature, the team extracted coffee's aroma, oils, flavor, and caffeine in under three minutes while using far less energy than a standard machine.
How the method works
The system attaches a small transducer to a traditional espresso basket. As it vibrates, high-frequency sound waves travel through the water and coffee grounds, creating acoustic cavitation. In simple terms, microscopic bubbles form and collapse, helping release compounds from the coffee more quickly.
That shift from heat to mechanical energy is the key innovation. The researchers found that the process can reduce energy use by up to 75%, which could matter not only for home brewing but also for large-scale ready-to-drink coffee production.
What the tests showed
To see whether the result could match conventional espresso, the team ran blind tastings with about 100 regular coffee drinkers. Participants compared standard espresso, ultrasound-brewed espresso, traditional filter coffee, and ultrasound-brewed filter coffee.
The outcome was striking: most tasters could not distinguish the two espresso versions in aroma, flavor, bitterness, or overall enjoyment. In the filter coffee test, the ultrasound-brewed version was even preferred overall, with a smoother bitterness profile.
Beyond cafés, the approach could support bottled coffee, milk-based drinks, and concentrated coffee products that are easier to transport and prepare later. The research points to a future where brewing can become faster, smarter, and more energy-efficient without changing the familiar coffee experience.