UNSW Sydney Researchers Develop Ultrasonic Espresso Brewing Method

Researchers at the University of New South Wales (UNSW) Sydney have developed a method to brew espresso-strength coffee using ultrasonic sound waves ^[1].

This development could fundamentally change the coffee industry by removing the requirement for high-pressure heating and boiling water. By eliminating these energy-intensive steps, the process makes coffee production more efficient and potentially less expensive for consumers and businesses [1, 2, 4].

The new technique allows for the creation of espresso-strength coffee using room-temperature water [1, 3]. Traditional espresso machines rely on heating water to near-boiling temperatures and forcing it through coffee grounds at high pressure to extract oils and flavors. The UNSW Sydney method replaces this mechanical pressure and heat with ultrasonic waves to achieve a similar extraction result [1, 2].

The research team said the method reduces energy use by up to 75% compared with conventional espresso brewing ^[2]. This reduction stems from the lack of a heating element and the energy required to maintain high pressure within a boiler system [1, 4].

The project was conducted at the university's facilities in Australia [1, 2]. While traditional methods prioritize heat to accelerate the solubility of coffee compounds, the ultrasonic approach uses sound waves to create cavitation—tiny bubbles that collapse and disrupt the coffee grounds to release flavor compounds into the room-temperature water ^[3].

This innovation targets the significant energy footprint of the global coffee industry. By shifting the brewing process away from thermal energy, the researchers aim to create a more sustainable model for high-strength coffee production [1, 2].