Can you make espresso with room-temperature water and sound waves?
Dr Francisco Trujillo and his team at UNSW have developed an entirely new brewing process that uses ultrasound to produce espresso-strength coffee in under three minutes, while using around one-quarter of the energy of a traditional espresso machine.
In this episode, Francisco takes us inside the science of ultrasonic coffee. We unpack acoustic cavitation, the microscopic bubbles that pit and fracture coffee grounds, why tamping matters far less in this system, and how the team built the technology into something that still looks surprisingly close to a normal espresso machine.
We also get into the taste test. One hundred regular coffee drinkers compared the ultrasonic brew with traditional espresso, with no significant difference found across the key sensory measures. Francisco explains where the drinks do differ, including crema, bitterness and aftertaste, and why the biggest opportunity may not be your local café at all, but large-scale ready-to-drink coffee production.
If you’re new here (welcome), our show dives into some of the best coffee conversations on the internet, but we will always remind ourselves at the end of the day: It’s Just Coffee!
CHAPTERS!
00:00 A New Way to Brew Coffee
01:17 How Ultrasonic Espresso Works
02:18 Where the Idea Came From
03:29 From Three-Minute Cold Brew to Espresso Strength
04:58 Acoustic Cavitation Explained
10:35 Brew Ratio, Grind Size and Tamping
13:54 Is It Really Espresso?
16:34 Why the Brew Takes Three Minutes
18:04 Testing Different Coffees and Roast Levels
19:29 Brewing With Room-Temperature Water
21:40 The Blind Taste Test
28:24 What Happens to Aroma?
31:05 Extraction Yield and TDS
32:23 Less Bitterness and a Cleaner Aftertaste
33:48 The Energy-Saving Opportunity
35:41 APAX LAB
36:54 Can Ultrasonic Coffee Scale Up?
39:19 Patents and Commercialisation
42:04 Francisco’s First Coffee Project
44:39 The Team Behind the Research
45:08 Where to Find Francisco’s Work
Dr Francisco Trujillo, UNSW: https://www.unsw.edu.au/staff/francisco-trujillo
Ultrasonic espresso research: https://doi.org/10.1016/j.jfoodeng.2026.113193
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Proudly sponsored by:
APAX LAB: https://apaxlab.com/
Riverina Fresh: https://www.riverinafresh.com.au/
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