The Ultrasonic Coffee Maker Creates Delicious Cold Brew Coffee in Just Minutes

A revolutionary method for quickly making cold brew coffee using ultrasound to extract flavor could significantly reduce brewing time from 24 hours to just a few minutes.

Cold brew coffee, produced by steeping coffee grounds in cold water, has gained popularity for its reduced bitterness compared to traditional hot water brewing methods. However, the lengthy 24-hour brewing process and the need for refrigeration space have posed challenges for coffee shops.

Researchers at the University of New South Wales in Sydney, led by Francisco Trujillo, have developed a unique ultrasound-based method to expedite cold brew coffee production, with the final drink ready in just 3 minutes.

The initial concept of using ultrasound waves to enhance flavor extraction was to increase antioxidants, though this didn’t prove true. Nonetheless, the use of ultrasound equipment yielded exceptionally good coffee. This process was later modified to utilize standard espresso machines at a fraction of the cost.

Trujillo remarked, “There’s nothing like it. It tastes and smells great, has a thicker, less bitter mouthfeel than a regular espresso shot, and has a level of acidity that people enjoy. It has become my preferred way to enjoy coffee.”

The researchers recommend a 60-second ultrasound process using intermittent water pumping for optimal cold espresso brewing. They also experimented with a three-minute brewing time.

Ultrasonic cold espresso showcases unique characteristics, as the coffee grounds remain intact unlike traditional methods. The emulsification of oils by the sound waves gives the coffee a distinct appearance and taste compared to traditional cold brew varieties.

A study conducted at the University of Queensland assessed aroma, texture, flavor, and aftertaste of the new cold brew samples produced by ultrasonic technology.

Trujillo noted that a one-minute ultrasonic shot scored similarly to coffee chilled for 24 hours but with a lower aroma intensity, indicating incomplete extraction. Meanwhile, the three-minute shot matched the 24-hour cold brew in aroma intensity but was slightly more bitter, reflecting over-extraction. Fine-tuning between 1 to 3 minutes can produce the perfect ultrasonic cold brew, according to Trujillo.