Brew Espresso With Sound Waves Instead of Hot Water

A team of researchers showed they can brew espresso using ultrasonic waves alone — no hot water needed. The result is a cup comparable to traditional espresso, and it uses 75 percent less energy.

The science is straightforward: ultrasonic waves agitate coffee grounds in cold water, extracting the same compounds that heat normally pulls out. Heat isn't the only way to brew — sound works too.

This could matter for the people who run corner coffee shops and food trucks, where energy bills are a real line item. A 75 percent cut in energy use for espresso machines could keep prices from creeping up on la gente.

Why this matters for us: If coffee shops and food trucks start using ultrasonic brewing, the savings could keep prices from rising for the people who buy them.