There are as almost as many kinds of coffee as there are of coffee drinkers, with each method for preparing the beverage appealing to a different kind of palate: moka pots, filter coffee, pour-over coffee, French presses, cold brews, espresso, and more produce their own unique flavours by extracting different compounds from the grounds to different degrees. Now, a new method has joined the throng: ultrasonic-assisted extraction, which can produce even an espresso at room temperature.

Espresso is normally made by forcing hot water through tightly-packed, finely-ground coffee beans, quickly producing a concentrated extraction. Its one of the hardest kinds of coffee to consistently make well, since the outcome is influenced by everything from grind size and packing density to temperature, pressure, and more. Ultrasonic agitation helps here by creating cavitation bubbles, which form shock waves as they collapse, breaking open the bean structure and producing small, strong jets of water. The experimental apparatus was built into a modified espresso machine. An ultrasonic transducer delivers vibrations to the basket containing the room-temperature slurry of coffee grounds for two or three minutes.

To quantify the results, the researchers analysed total dissolved solids, extraction yield, pH, colour, volatile components, and caffeine and chlorogenic acid contents. By varying ultrasonic power and grind size, the extraction yield and dissolved solids could be adjusted to closely match traditional espresso or cold-brew coffee. The other metrics had no significant differences, and a survey of 100 coffee drinkers found no preference between this and traditional espresso. When the drinkers tried the cold-brew coffees, they preferred the version made with ultrasonic assistance. The experiment succeeded in its goal of reducing energy consumption: the ultrasonic-assisted coffee took about a quarter as much power to make.

If you still prefer a more traditional approach, we’ve covered some beautiful espresso machines before, including one made out of motorcycle engine parts.

Rodrigo Arias Mallo, maintainer of the Dillo web browser, has written a blog post with a proposal on one way to ensure that a contribution is written by a human and not AI; he suggests asking new contributors to record their programming session using asciinema.

In the same way that LLMs generate patches, they can also generate the asciinema recordings themselves. Then, the contributors can lie to the reviewers pretending to have made the edits. Perhaps surprisingly, this is not a easy task for LLMs, at least from my observations. The corpus of recordings of developers making mistakes and thinking the whole process of editing a file is not as large as the corpus of FOSS programs and patches in which to train an LLM. During my very simple tests I haven't been able to generate an asciinema session that remotely resembles what I would expect from a human, and even less so from a human with a nice editor theme and editing an existing Dillo source file.

The Dillo project is not yet requiring asciinema recordings, but he said that he would like to test the theory further. LWN covered asciinema in January 2026.

Update: the New York Times has published an obituary of Dr. Neuman.