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.
My dad was stationed on a submarine in the navy and he and a few others used to dump their laundry in the ultra-sonic cleaner normally used to clean engine parts. Said it did a great job....
After the last one of these posts talking about cold brew coffee I attempted to replicate the results by just throwing some water and coffee into an ultrasonic jewelry cleaner. Results were not satisfactory. I wonder if extracting the transducer from the jewelry cleaner and attaching it to my Portafilter would work.
It'd be a learning experience to find the right settings.
Coffee usually goes in two directions. Under-extracted (sour) or over-extracted (bitter). Things that will affect the extraction are temperature (hotter usually means more extraction), time (longer = more), grind size (more surface area in smaller grinds = more), pressure (higher = more) etc. Roast levels also matter.
I tend to wake up before my partner, and I can only imagine the look on her face when the ritualistic grinder noise gets joined by a noisy brewer.
In all seriousness, people tend to have a routine around coffee, but I think the Aeropress showed that people will change if the result is meaningfully better.
As I glance at my (checks notes) $200 power bill in San Diego apartment used entirely to run 3 ceiling fans and a box fan, I’m getting curious about all the ways power consumption can be reduced. No AC, LED lights, all gas appliances.
I am going to switch over to a bunch of DC tower fans which claim to cut energy usage substantially. I wish more appliances would just switch to DC motors.
Look into balcony solar, if you have a balcony with sun exposure.
California energy prices are among the highest anywhere, so anything you can do to cut usage will have a bigger payoff there, and justify some investment to achieve it.
You may want to do a basic audit of your electrical usage -- it's not unheard of for apartments to have messed up circuits where one pays for usage by another.
If you turn off all of your AC consuming devices is your meter still registering usage?
"Most of us think of espresso as a hot, high-pressure ritual." - No, most of us dont care how the sausage is made, and just want the end product. Sure theres lots of individual coffee enthusiasts who cares, but in % terms thats not "most of us", most of us do not care, and nobody in my 40 years of life has ever complained about coffee energy usage.
Extract with sound waves is an interesting idea, but dont romanticize demand that doesnt exist, it wrecks credibility, literally in the first sentence of the article
"You got your cold brew, your Japanese iced coffee, your iced americano. Then there's your mazagran, that's coffee with lemon juice, real refreshing. Your espresso tonic. Your iced latte, iced cappuccino, iced macchiato. You got your iced mocha, your frappuccino, your Greek frappé. Vietnamese iced coffee with the condensed milk dripping down real slow. Affogato, that's espresso poured right over ice cream. That's... that's about it."
The target of this process is not the residential use, but industry processing.
Instead of heating water to extract coffee and then latter cooling it to freeze dry and make instant coffee you keep the whole process at low temperatures, saving lots of power.
Sparkling water (8-10C is the recommendation on the bottle in my hand).
Bread (fresh from the oven, toast).
Chicken Soup.
And leaving aside examples, many things do taste better when they are hotter then 25, the heat helps more particles reach the olfactory receptors in your nose.
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.