Extraction of flavor etc from coffee grounds changes based on the water temperature. You can easily experiment with this by taking some coffee grounds and trying to brew with various temperatures, and noticing what flavors you get out.
There's a reason cold-brew needs hours and hours to extract a good coffee flavor while regular espresso or pourover is done in a matter of minutes.
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.
For industrial processes it probably doesn't matter - look at how nescafe is manufactured.
"This doesn’t mean drinking room-temperature coffee exclusively. The complete experience encompasses the entire temperature journey." and "High temperatures deliver immediate aromatic impact—the unique, irreplaceable value of fresh coffee."
I'm also not sure bitterness should be considered a defect in coffee, it's part of the flavor profile and actually peaks in perception at a higher temperature according to that article.
I'm always wary of studies that claim that there is some optimal way to have coffee. People have different preferences.
The "optimal" drinking temperature of espresso is still considered higher than 50 degrees, like 60-65 degrees, though of course that is subjective, but the nice aspect of serving it hotter is that those that enjoy it hotter can have it and then it cools quickly and the customer can choose when to enjoy it or get to enjoy it at multiple temps.
I'm surprised you associated it with espresso. Creamer and drip coffee machines go together. Milk and espresso machines go together. I've seem drip coffee machines with real milk, but I've never seen an espresso machine with just creamer.
It tends to exist primarily in office environments, because it can stand not to be refrigerated and was the first lactose-free option. Therefore it was easy to buy one bottle and solve the problem of "stuff to add to coffee".
I make espresso at home by grinding/tamping it myself so I admittedly don't know much about the pod version or whether that still counts as espresso.
Espresso is so named because you "express" the brew from the beans and you do that with water because water is pretty neutral in flavour, is not poisonous and has quite a few other properties that we have evolved to exploit or live with.
Milk is a weird liquid associated with mammals nursing infants. We humans have evolved to be somewhat lactose tolerant post infancy which is rare in animalia (1)
Given that we are using the Italian word - espresso - then let's use their definition. If you add milk then you have a latte or a cappuccino or an americano con latte, a flat white or whatever.
Real weirdos try to milk oats. I've tried but I can't find their teats.
as in, a glass of just milk?
And lactose free milk is a thing, for those of us who can't have lactose anymore.
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!
Espresso, pour overs and even cupping shows you different aspects of the coffee when it cools. In fact, if you follow SCA cupping protocol, one of the most important parts is to evaluate the coffee at room temperature.
I can't recall any amazing cups I drank that became worse when they were cool (both V60s and espresso). They become sweet and syrupy, less harsh and bitter. They taste like juice and it just makes you joyful for some reason, it is almost unbelievable that this is coffee.
But the framing of the article around espresso specifically is somewhat bizarre. Most people want their shot of espresso to be piping hot, not room temperature. And most iced coffee is very intentionally not made with espresso (although you certainly can use it if you want).
The text of the article seems to suggest that this is more intended for "making ready-to-drink coffee products at industrial scale". But then that is not single-serve espresso shots that the article shows in several images.
So is this about room-temperature espresso shots (not what most people want) or about industrial-scale concentrated coffee? And if it's the latter, what would those machines look like? It's one thing to use ultrasound at a small scale; but what about in gigantic basins? Does that work, or are there challenges? Is this tech that scales?
Really? How is it made?
https://www.youtube.com/watch?v=YlQT4ptwLKs
I was inspired by the above video and have been playing around with ultrasonically aged drinks for quite some time now. It's quite fun. Still haven't brought myself to try ultrasonically aged milk yet though.
For domestic use, in the home of somebody whose coffee snobbery is dialled to 11, I need far more information.
What beans were they using, freshness, etc? (Edit: Campos coffee… not on my shopping list that’s for sure…)
How did they control for extraction method differences to maximise output quality for all brew methods? (Edit: TDS and EY)
Were the “regular” coffee drinkers regular consumers of espresso?
Most importantly, how long until Hoffman does a deep dive and much will it cost so I can allocate budget for yet another coffee making device?
I felt a great disturbance in Italy, as if millions of voices suddenly cried out in terror and were suddenly silenced.
Espresso does not have milk.
Macchiato, is an espresso based drink with milk.
Edit: it's bad form to change your message after-the-fact to remove the thing that was quoted.
Edited to remove because the paper clarifies that it’s black coffee. But missed the (edit- found the clarification). Was quoted whilst in the process of fixing!
You're using the term in an unnecessarily specific way.
For those sensitive souls I'd think they'd be more worried about "Expresso","Frappacino", "Puppacino", Starbucks, and 20oz "venti" lattes.
I’m from Melbourne, have a Brewtus IV + Mazza Mini, probably have a low user ID on coffeesnobs, hung out every day our Prouds and Patricia’s, and can tell from first sip if the beans are South American, African, or from Sumatra, so you can probably tell I’m anal about my coffee… and all I can say is don’t knock Campos (especially their King Street).
When I have a guest that wants a hot coffee, I just pour the shot into a mug and top it up with hot water to their taste, which works great.
What this isn't is anything new. That doesn't make it bad, but it's not novel.
The biggest downside: rinsing. You have to do it manually. And no, just refreshing the water and letting the ultrasonic emitter run will do nothing. And doing it manually takes a surprising amount of time.
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.
The best coffee that I've drank for the past five years have all been pour overs (my favorite was at a place called The Library in Toronto). I sometimes wonder if all the time, effort, and money I've dumped into espresso has been a huge mistake and maybe I should just buy a pour over setup...
Channeling is usually caused by too fine of a grind. If your machine (I'm assuming it's a pump machine) is pegging the pressure gauge at max (and dumping excess pressure internally) and your coffee tastes unevenly extracted, you may want to try grinding coarser. Not only will this reduce channeling, it'll result in less fines in the cup, also reducing bitterness.
The best thing I ever did for my espresso was to give up on the rigid rules I was first taught as a beginner. I don't time my shots, I don't use fixed brew ratios, I do everything by feel (watching the pressure build and the coffee flow) and taste. I do use a scale (for weighing beans per dose and weighing shots for repeatability). I dial in by adjusting the coffee output rather than fiddling with the grind. I only set the grind once to get a reasonable pressure (6-9 bars, no maxing out or dropping off), then fine-tune the gram output.
The biggest insight I gained from this freestyle approach is that the standard 2:1 ratio is altogether wrong for most of the light-roasted coffees you get from specialty coffee roasters. They simply will not extract properly with that small amount of water. Grinding coarser and pulling a longer shot (sometimes called a "turbo shot") gives you a much better result.
Usually the cause is channeling, where some pathways in the coffee puck are easier for water to get through, so they get eroded first which leads to even more water going through these channels. Coffee around these channels then gets over extracted (bitter).
Conversely, much less water is reaching the other parts of the puck, leading to those parts getting under extracted (sour)
Better puck prep helps. Using a WDT tool (some acupuncture needles on a cork would do) or a blind shaker to break up the clumps leads to good results. Making sure the surface of the puck is level after tamping is a big one as well.
What also helps is going coarser in the grind. The coarser the grind, the less puck prep matters and the less channeling occurs. Warning, you’ll no longer be getting the thick crema you may associate with espresso, or the instagram worthy beautiful rat tail extractions. But the coffee produced from coarse grind espresso is IMO much better.
I was taught a lot of this by Lance Hedrick and I applied these learnings to achieve mostly consistent fruity and sweet espresso on most mornings.
Also shoutout the library. Great shop
Edit: and if you want a non-bitter coffee, skip the pour over and cold brew, and go straight for the cold drip (one drop every second over 24 hours). And when from the fridge, let it sit to get to room temperature - now you have a non-bitter, flavoursome coffee that has a whiskey mouth feel
https://www.sciencedirect.com/science/article/pii/S135041772...
AI generated/hallucinated article? Or no one, author or editor, read it before publishing?
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.
When working with ultrasound, I think of it the context of a micro-agitator versus the large scale shaking, snipping, and slapping clothes against rocks methods.
"Ultrasound machines vibrate everything around them therefore make sound" does not imply "I vibrate everything around me therefore make ultrasound."
I get the sense that these people think calling something espresso is a mark of quality, but it's just a brewing method like any other...
I like my coffee heavy metal.
In any case, I think there are frauds in all ranks of universities. I've seen people in CMU steal someone else's research idea or even a whole paper and the university doesn't punish the professors who did this. It's the PhD students whose work and life gets destroyed by such things.
Even if it draws 1.5kW constant for 24h/day that’s only 36kWh. That’s about ~$5 to ~$15 of electricity, depending on how mismanaged your utility is.
It costs less than an hour of labor to power an espresso machine for an entire day, the energy cost to pull a shot is negligible, pennies. The rooftop unit cooling and heating the coffee shop probably uses 2-3x more energy.
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.
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.
We have the most expensive electricity rates in the country - both summer and winter are over $0.50/kWh.
I pay 0.45 Euro for public car charging, returning the cost of installing a charger at my (rented) house will probably take 2 years.
$200 / $0.50 = 400kWh / 720 hours = 556 watts of load on average, which is more power than I use to run a 1-ton AC unit on auto.
BLDC motors are fairly common these days in HVAC equipment, speed control is much easier and they’re more efficient.
> I am going to switch over to a bunch of DC tower fans which claim to cut energy usage substantially.
I’m guessing they’re made by Vornado?
If you turn off all of your AC consuming devices is your meter still registering usage?
But, yuck, who on earth wants to drink actual espresso at room temperature?
"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."
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.
I think almost everything tastes better at room-ish temperature.
(Some things need to be colder or hotter to keep their texture, but I can't think of anything that _tastes_ better outside of the 16~25°C range)
Even though I don't doubt your claim that some particles travel easier at higher degrees I suspect the difference is too small to notice before the rise in temperature becomes distracting to _me_.
- The taste is apparently the same "There were no significant differences in aroma, flavour, bitterness or overall liking."
- That ultrasonic horn looks a lot smaller than both a modern espresso machine or a hand-cranked model like a Flair/Rok.
For home use I'm much more interested in being able to add it to cold drinks and desserts.
Cutting costs does make sense for this type of product, but is it enough to keep up with declining demand?
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
“Saving up to 75% of energy by not heating the water is a minor benefit for home users or small coffee shops. But for companies making ready-to-drink coffee products at industrial scale…”
The instant and dried coffee market is $35B-$50B. Cold Brew another $3B-$4B.