Scientists brew espresso using room-temperature water and sound waves.

Scientists brew espresso using room-temperature water and sound waves. Researchers at UNSW Sydney have created a new way to make espresso using room-temperature water and ultrasonic sound waves. The method can reduce energy use by up to 75% compared with traditional espresso brewing. High-frequency sound waves extract flavour, aroma and caffeine from coffee grounds without the need for heat. Scientists say the process produces espresso-strength coffee in less than three minutes. In blind taste tests, around 100 regular coffee drinkers could not tell the difference between the ultrasonic coffee and a traditional espresso. The technology uses tiny collapsing bubbles to quickly release flavour compounds, oils and caffeine into the water. Researchers believe the system could help large-scale coffee manufacturers produce ready-to-drink beverages more efficiently.