Ultrasound Technology Brews Cold Coffee in Minutes, Rivaling 24-Hour Method

Scientists at the University of New South Wales have developed an ultrasound technology that can produce cold brew coffee in 1-3 minutes, matching the taste profile of traditional cold brew. The innovative method uses ultrasonic pulses to extract coffee compounds, resulting in a beverage with higher caffeine levels.

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Bijay Laxmi
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Ultrasound Technology Brews Cold Coffee in Minutes, Rivaling 24-Hour Method

Ultrasound Technology Brews Cold Coffee in Minutes, Rivaling 24-Hour Method

In a groundbreaking development, scientists at the University of New South Wales in Sydney have created an innovative ultrasound technology that can produce cold brew coffee in just 1-3 minutes. This breakthrough matches the taste profile of traditional cold brew coffee, which typically takes 24 hours to steep.

Why this matters: This innovative technology has the potential to disrupt the coffee industry, making high-quality cold brew coffee more accessible to a wider audience and changing the way coffee is produced and consumed. As the demand for specialty coffee continues to grow, this technology could have significant economic and environmental implications.

The research team, led by Dr. Jaqueline Nadolny from the Queensland Alliance for Agriculture and Food Innovation (QAAFI), modified an existing espresso machine to accommodate an ultrasonic transducer. This device administers ultrasonic pulses to the coffee grounds, significantly reducing the brewing time from several hours to under three minutes.

The ultrasound technology uses a bolt-clawed transducer connected to the brewing basket with a metal horn. By applying 38.8 kHz sound waves, the filter basket is transformed into a powerful ultrasonic reactor. The acoustic bubbles produced by the sound waves dissolve small grains of coffee, releasing more of the 2,000 compounds found in coffee beans into the water.

The researchers conducted taste tests with the help of 11 paid testers who compared the taste profiles of coffee made using three methods: ultrasound for 1 or 3 minutes, and 24 hours of traditional cold brewing. The results showed that the 1-minute sonicated coffee matched ordinary cold brew on measures of flavor and aftertaste, while the 3-minute sonicated coffee matched on aroma intensity and scent of dark chocolate.

Co-author Francisco Trujillo of UNSW Sydney expressed his enthusiasm for the new brewing method, stating, "There's nothing like it. The flavor is nice, the aroma is nice and the mouthfeel is more viscous and there's less bitterness than a regular espresso shot. And it has a level of acidity that people seem to like. It's now my favorite way to drink coffee."

The cold brew method has gained popularity in recent years due to its less bitter taste compared to traditionally brewed coffee. It involves mixing coffee grounds with room-temperature water and allowing it to steep for several hours to two days. Previous studies have explored the chemistry of coffee, but few have specifically focused on cold-brew coffee.

The University of New South Wales researchers' 2020 study investigated the extraction yields of light-, medium-, and dark-roast coffee beans during the cold-brew process. They found significant differences between hot- and cold-brew methods when medium- and dark-roast coffee beans were used.

This innovative ultrasound technology not only drastically reduces the brewing time for cold brew coffee but also produces a beverage with higher caffeine levels, potentially even surpassing espresso. The breakthrough could make high-quality cold brew coffee more accessible to a wider audience, including those who are short on time or lack the necessary equipment for traditional cold brewing methods.