Food Ultrasound

For as long as espresso has existed, its defining ritual has been the same: hot water, forced under high pressure through finely ground coffee, in about thirty seconds. That heat and pressure are what most of us assume are non-negotiable, the whole reason espresso tastes the way it does. In June 2026, a research team at UNSW Sydney's School of Chemical Engineering, led by Dr Francisco Trujillo, published findings in the Journal of Food Engineering suggesting that assumption might not hold. They built what they call an "ultrasonic espresso," a brewing process that produces espresso-strength coffee using room-temperature water in two to three minutes, while cutting energy use by roughly 75%. Sound Instead of Steam The mechanism at the heart of the breakthrough is acoustic cavitation, the same physical phenomenon that shows up across a growing range of ultrasonic food and beverage applications. High-frequency sound waves are driven into a slurry of cold water and ground co...