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.
"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.
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.
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!
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.
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.
Even if that quote was left in, "espresso drinkS" usually stands for drinks based on espresso, not espresso itself. You know, like cappucino or macchiato.
Correct. An espresso drink may have milk in it. An espresso does not.
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!
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.
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...
If your espresso is bitter and sour, you're getting uneven extraction. One reason for this includes channeling: water encountering a tightly-packed puck and boring a hole through it or even lifting the puck so that water flows around it. Channeling over-extracts the areas of the puck that experience a high flow rate and under-extracts the areas that experience low flow.
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.
What you’ve hit is uneven extraction. Parts of the puck were over extracted and other parts under extracted.
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.
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.
^-- this comment was typed on a computer, similar to the computers the worlds most advanced AI is developed on, so you know he knows what he's talking about.
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.
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.
An espresso machine is essentially a 1-2kW electric boiler, a compressor pump, some valves/actuators, and some PIDs, right?
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.
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.
I just checked my plan yesterday, I pay 0.13 Eur, summer and winter. I can commit to my provider for a year and lower it to 0.11, but with slightly higher fixed monthly cost (which is about 50 eur, regardless of consumption). With this prices you less likely to think about the efficiency of fans - it will probably will years to return the cost of fan replacement.
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.
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
“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.
"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.
I'm sure that is correct for many people, but as I said: to _me_ things taste better at around room temperature.
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_.
Well, you know what's taste good and what's not - for you. You are the only judge for your own experience, and taste is an experience of the brain, not something out there. Nevertheless, most people do prefer hot meals, and there's scientifically explanation for that.
Not really I think, but it’s not uncommon to protect product by restricting production methods or ingredients to traditional ones. So name espresso could be legally restricted to only when it’s brewed in traditional way.
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.
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!
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!
[1]: https://news.ycombinator.com/item?id=48552440
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
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.
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.
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.
$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?
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.
If you turn off all of your AC consuming devices is your meter still registering usage?
- 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.
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_.