[kowalej]

This seems very interesting, at least from a pure coffee nerd standpoint and what it could mean for improving espresso brewing in general.

However, I'm going through the research paper, and am a bit skeptical of the energy savings angle, especially considering the many variables with espresso machine in terms of how they heat and brew (single vs dual boilers, heat exchangers vs dippers, spring lever machines vs pump driven). I'm weary of how they are doing a baseline comparison here, especially because the paper states that the comparison was done between a modified Ascaso machine (with the ultrasound gizmo) vs an entirely different machine (Sanremo Cube); and also that they swapped the Ascaso machine's original brew pump and put in a seemingly expensive, but more efficient "positive displacement magnetic gear pump". They still use the pump to drive about 11 bar of pressure during brewing with it run on some sort of interval schedule throughout the 3 minute cycle. They did factor out the initial heat up times which I guess makes sense.

However, another thing (on top of the obvious "room temperature espresso" problem) is that you'd still need steam / heat to produce milk based drinks (relevant for both home and especially cafes). Depending on the machine (including the Sanremo Cube they tested with) some of the "idle energy" usage is to support on demand steam generation. This doesn't seem to have been factored into their energy model which is pretty sketchy.

[hdndjsbbs]

"room temperature espresso" was the first thing I thought of - espresso is meant to be drunk hot, right away. If you let a good shot cool off and compare it to a bad shot you're not going to notice the difference as much because you made them both worse by letting them sit and cool.

For industrial processes it probably doesn't matter - look at how nescafe is manufactured.

[pfdietz]

I wonder if this process would work if the water were replaced with milk. Milk would degrade at high temperature, but this (at least in bulk) is at room temperature.

[brian-m]

Would be awesome for industrial processes if it can be scaled, is comparable in price to heating water, and preserves what makes a good espresso a good espresso.

Was talking with a roaster who was providing espresso to a distillery recently. The distiller had tried a range of other products but only espresso shots were giving the flavour they were chasing. Needless to say, it ended up being a pretty limited run because the guys grew tired of pulling litres of shots for a batch!

[Skunkleton]

If your goal is to understand the quality of the espresso shot, rather than experience a high quality espresso shot, letting it cool off provides a useful data point.

[kowalej]

Ok, I just looked it up and the Ascaso Uno is a thermoblock design, while the Sanremo Cube is an HX machine with a full on steam boiler. Therefore, the Ascaso wouldn't even have instant on steaming and has basically no stand-by power usage. So yea... their comparison is bogus, unless I'm missing something from the paper.