alt.hn

6/16/2026 at 8:52:06 AM

Making espresso with ultrasound

 https://www.unsw.edu.au/newsroom/news/2026/06/New-way-making-espresso

by darktoto

6/16/2026 at 10:16:51 AM

> Both espresso samples were served at 22 °C to ensure a fair like-for-like comparison […]

> It is noted that espresso is normally consumed hot and has transient sensory attributes that are temperature- and time-dependent. Hence, serving espresso at 22 °C will alter its sensory characteristics.

This is a weird test, coffee get’s so much worse when cold. So people can’t distinguish between two bad coffees.

by jurf

6/16/2026 at 5:57:25 PM

> coffee get’s so much worse when cold

This is a myth. Bad coffee tastes better when hot because your sense of taste is dulled - reducing bitterness. Also, at higher temperatures, aromatics and volatile compounds are more airborne, improving the smell of coffee. Good coffee is better enjoyed around 60-70C

by cush

6/16/2026 at 7:00:15 PM

I don’t understand, you say it’s a myth and then said it’s better when warm?

Regardless, I would say it’s an objective fact that good coffee is ruined at room temperature. It still tastes fine, but no where near as good.

What especially irks me is that they could have just heated the stuff in a microwave [1] to 50°C and have a much better test.

[1] https://youtu.be/yqgKlqAUM9g

by jurf

6/17/2026 at 11:59:37 PM

I meant it's better when cooled, not straight off the boil. Bad coffee tastes better when it's too hot to drink. Good coffee tastes better when it's cooled.

by cush

6/17/2026 at 6:53:56 PM

No way. I make espresso over ice and it's great, a lot better than cold brew. The Greek make just about any coffee using the espresso machine over ice and Koreans are quite fond of their iced Americanos, which are a bit dilluted for me but I also enjoy them from time to time. I also made Aeropress over ice with specialty coffee and its was better than the hot drink prepared using the same cofee and recipe. I just do it during summer when one would normally enjoy ice cream, the rest of the time I drink the usual hot espressos.

Room temperature coffe is just like room temperature water: boring.

Our espresso machine (De'Longhi) makes cold brew in like a minute or two. Brilliant. It's tastes like normal cold brew but I enjoy espresso over ice better. Maybe this ultrasonic espresso machine could achieve better extraction with cold water than purely pumping water at high pressure through coffee?

Anyway I'd be quite excited to see a review by James Hoffmann when it hits the market.

by petre

6/16/2026 at 5:46:11 PM

> coffee get’s so much worse when cold

Coldbrew is a thing and done right it brings out a refreshing sweetness. Also iced coffee. Bad coffee is bad hot or cold.

by hylaride

6/16/2026 at 8:51:12 PM

"Cold brew" means that the coffee was brewed with "cold" water. Whether or not it is served cold is orthogonal -- iced coffee is usually brewed hot.

by david-gpu

6/16/2026 at 7:12:43 PM

I love coffee on ice in summer, but I think that’s a different category, like ice cream.

I would rather have room temperature coffee than a cold brew usually though. I just did not have good luck with it so far

by jurf

6/16/2026 at 4:42:39 PM

"Good" (well-extracted) coffee is still relatively good when warm, especially compared to "bad" (over-extracted, or under-extracted) coffee. That said, many believe that the optimal temperature for serving coffee is 50-60 degrees celsius (122-140 degrees fahrenheit).

by nickff

6/16/2026 at 6:53:07 PM

Yes, but the test was at 22°C, which I wouldn’t consider warm. And it’s too cold for the differences to be even perceptible well, making the test flawed. Disregarding the fact that it’s also much colder than people use to drink coffee, making it even harder to distinguish for non-experts.

by jurf

6/17/2026 at 9:30:38 AM

Wonder why they chose to stick with the portafilter form factor rather than something custom for the method. Perhaps it just fits the task well and they don't need to change, or they want to preserve the look of an espresso machine. Though, if the water is room temp, they only really need the pressure, which doesn't need the entire machine. Seems pretty cool.

Edit: The article shows that they chose this method specifically to use the basket, and the basket allows for the vibrations they need. The other conveniences of the basket form factor also come into play; reloading, cleaning, etc. and don't need reinventing or retraining. Cool stuff. I wonder whether they'll remodel the machine around the basket and remove what's not needed if this becomes a product.

by nusl

6/17/2026 at 4:23:17 PM

Consistency in output - this is a standard test model to replicate entire existing system and then apply changes components of the system to test a theory.

by The_President

6/16/2026 at 5:50:30 PM

This is really cool, I have so many questions! What's interesting to me is they only replaced the hot water part of the equation, and the system still requires high pressure.

How does ultrasound affect flow rate? Do fines sink to the bottom of the puck and choke the shot?

There is a new movement happening, especially in lighter roast coffees, where we're finding that more balanced extractions (less bitterness/acidity/acridity) are happening at lower pressures, even going so far as grinding so coarse that the puck offers zero resistance - effectively making the pump the limiting factor for flow rate. Light roast coffee is much less porous and more hydrophobic.

I wonder if adding ultrasound would allow light roasts to yield more extraction in general, maybe even keeping the high temperature. Or, would adding ultrasound allow a finer grind size and more resistance without adding the harsh flavors of a high-temperature shot.

So many experiments to be done!

by cush

6/16/2026 at 10:13:11 AM

Does this work with cold water? Because if so, my iced espresso drinks are crying out for it

Where's James Hoffmann when you need him?

by swiftcoder

6/16/2026 at 10:13:04 AM

What exactly is the innovation here compared to the press release from two years ago?[1]

[1]: https://www.unsw.edu.au/newsroom/news/2024/05/Ultrasonic_col...

by erikgahner

6/16/2026 at 10:39:11 AM

Different kind of coffee drink being prepared; espresso vs cold brew.

(You might quibble whether it's actually espresso if there's not pressure and it's extracted cold; but it's closer to espresso in strength.)

by klausa

6/16/2026 at 4:24:05 PM

Got it, thanks!

by erikgahner

6/16/2026 at 5:16:30 PM

This sounds awful. I’m an espresso snob and caffeine isn’t even on my list of why I love it. It’s like they complete ignored what makes a good shot and focused on one element.

by supertroop

6/16/2026 at 5:18:35 PM

> “And when we gave our ultrasonic espresso to 100 regular coffee drinkers in a randomised test, they could not tell it apart from a normal espresso.”

I like the ritual of it, for sure, but I'm not sure that's what makes it a good shot?

by ceejayoz

6/16/2026 at 5:21:08 PM

Regular coffee drinkers vs snobs are two vastly different categories. In the guy that ruins your fun. ;)

by supertroop

6/16/2026 at 5:27:01 PM

I grow my own beans and harvest rain water from my roof to use in my coffee ritual and ... am happy to let others do their own thing

by slwvx

6/16/2026 at 6:22:46 PM

I actually capture free hydrogen and oxygen and make my own water.

by wuliwong

6/17/2026 at 8:48:57 AM

If you're not creating your own galaxy which can make free hydrogen, oxygen, and an environment to promote the evolution of a coffee plant over millions of years, you're consuming such an inferior product that you might as well drink instant coffee.

by manarth

6/16/2026 at 6:27:11 PM

I literally have a friend that roasts their own and has a rainwater collection system.

by supertroop

6/16/2026 at 6:15:42 PM

I'm also an espresso snob and got the complete opposite take. The idea of decoupling grind size and brew time from yield is super interesting. The only other device I'm aware of that does this is a pressurized portafilter basket but that's only there for people that don't have good enough grinders.

by duped

6/16/2026 at 5:39:43 PM

I'm curious why you focused on caffeine when the article says their study found that people tasted no difference

by cush

6/17/2026 at 7:23:30 PM

I'm sure someone like Giovanni Gaggia will improve it a bit, to the point there is nothing to improve anymore.

by petre

6/16/2026 at 11:09:19 PM

It immediately brings to mind that YouTube video where a guy was making whiskey out of vodka and oak chips in an ultrasonic bath.

by cocodill

6/17/2026 at 1:26:12 PM

> For filter coffee, however, the ultrasound-brewed version performed even better: participants significantly preferred it overall, particularly rating its bitterness as more pleasant.

I'm surprised by this, my assumption from hot coffee vs cold brew was that since the water isn't hot, there wouldn't be as much bitterness? Or maybe I'm reading it wrong and it's why they prefer it, because it's less bitter?

by m-p-3

6/17/2026 at 7:19:02 PM

Then just get a lighter roast and don't over extract? Also if it's espresso get rid of the crema. Looks geat, tastes awfully bitter.

by petre

6/16/2026 at 9:29:44 AM

But people want to drink coffee/espresso hot, not room-temperature. So you have to heat the water afterward anyway. I'm not seeing that much potential for energy savings here, unless you're comparing setups with large boilers inefficiently used for small amounts of coffee.

by fabian2k

6/16/2026 at 9:35:49 AM

According to the article they see the main use for industrial scale production of coffee/espresso based drinks, in that regard it does make sense. For home use not so much even if there could be some niche market for cold espresso drinks at home, using less ice would allow for less dilution and faster than prepping and then refrigerate the coffee. I sometimes put concentrated ice coffee into my whey/oat shakes, but this is indeed very niche use even for me.

by hultner

6/16/2026 at 10:01:22 AM

I have friend with a Jura coffeemaker.

Makes nice coffee, but I don’t think it’s worth the cost (but he has a lot of money, so it’s not a big deal for him).

I envision some fairly high-end kit, coming from this.

by ChrisMarshallNY

6/16/2026 at 9:32:08 AM

They explicitly mention large scale producers for mixed drinks as a massive target audience. E.g. iced coffee manufacturing will be heavily impacted, they would normally need to heat the liquid, extract the coffee and then cool it back down.

by tjcvirage

6/16/2026 at 9:40:44 AM

If I read it correctly, they did espresso and filter taste tests at room temperature (thought they don't state the exact temperature, and how they managed to brew filter coffee with the described setup). Overall the press release is somewhat misleading in what the goal is until the part you mention. If the focus is industrial production of cold, mixed coffee drinks I'd have expected more quantitative measurements instead of taste tests. Testing how well your coffee is extracted is pretty trivial with the right equipment.

by fabian2k

6/16/2026 at 10:58:45 AM

There's plenty of TDS and other extraction charts in the actual paper.

by klausa

6/16/2026 at 10:30:23 AM

> But people want to drink coffee/espresso hot

An awful lot of people drink iced espresso drinks these days. Room temperature (or below) brewing would make a big difference to the dilution in those drinks.

by swiftcoder

6/16/2026 at 10:01:11 AM

To be fair, precedent has already been made with cold brew.

by exitb

6/16/2026 at 9:56:20 AM

I usually forget about my coffee anyway until it's cold.

by ma2kx

6/16/2026 at 6:01:07 PM

mmm.. what about pressure? the real espresso need pressure... is not just hot water. is the pressure of the expanding water that pushes it... not sure it would be the same stuff lol

by Febriss33

6/16/2026 at 7:29:28 PM

There is still pressure

by cush

6/17/2026 at 10:31:23 AM

you are right. i went to the paper, the original post is not clear about it.. they claim 11 bar instead of 9 of the normal espresso. well, just curious now to try it....

by Febriss33

6/16/2026 at 9:22:25 AM

Someone get James Hoffmann on the line right now.

by thomasoffinga

6/16/2026 at 10:21:47 AM

I will wait for his blind testing before homebrewing this one.

Might be a new meta for iced lattes.

by willis936

6/16/2026 at 9:37:21 AM

The American tech video is still surprising me.

by intended

6/16/2026 at 9:22:54 AM

75% energy save to make a room temperature expresso. I am ok spending a bit more energy to have it warm.

by mzitelli

6/16/2026 at 9:45:05 AM

I'm _very much_ a coffee nerd.

There's a semi-famous, super hipster cafe near me in Tokyo, that I sometimes go to.

Once, they had a special on the menu, when they give you a flat white, and a double shot of espresso on the side, with a thermometer hovering over the shot, with suggestions of tasting notes that you can get out from sips at different temperatures.

Now, that's generally very much a thing — things definitely taste differently based on the temperature (or maybe _they_ don't, but we _perceive_ them differently? distinction without a difference, I guess.).

The suggested temperature ranges were 51-40C; 40-30C, and 30-20C.

51-40 was great. 40-30 was getting weird, but still _interesting_, because you definitely got different notes.

But the 30-20 was terrible. That is absolutely too cool to enjoy a shot of espresso. I'm all for experimentation and doing weird things, but that was no longer riding the line of "not great but interesting" and went straight into "why would you ever do this" territory.

by klausa

6/16/2026 at 9:52:04 AM

Cool! I noticed most of my Chinese friends drink cold or iced coffee. Undrinkable imho but yeah, there is def. a market.

by thenthenthen

6/16/2026 at 9:28:53 AM

It is intended for manufacturing canned iced lattes and similar, as stated in the article.

by elil17

6/16/2026 at 9:34:58 AM

> The saving could be especially significant for companies who make coffee-based ready-to-drink products at industrial scale

It's not for you

by moodyScarf

6/16/2026 at 9:26:03 AM

Think of how cool you'll look with an oscilloscope on top of your coffee machine, though.

by alansaber

6/16/2026 at 9:36:10 AM

Could be great for an iced Americano

by weird-eye-issue

6/16/2026 at 9:27:54 AM

Awesome idea. I would love to try it. If that can also make my espresso routine easier I am up for it.

by uberex

6/16/2026 at 8:57:36 PM

If you are looking for an easier routine, have you tried the OXO rapid brewer to make "soup"? It is as easy to operate as an Aeropress, and it makes a really yummy concentrated cup.

A typical recipe is something like 20g coffee and 80g water, yielding about 60g of concentrated coffee. Lance Hedrick has done a few videos on the subject.

It is not espresso, obviously, but it takes no time to prepare, it tastes fantastic and it is very easy to dial-in.

by david-gpu

6/18/2026 at 10:45:46 AM

Is this an actual hack on HN? Well, no. Not, really. But almost.

Still, pretty cool.

by a96

6/16/2026 at 5:38:24 PM

Of all the objective and subjective metrics a home coffee drinker is trying to optimize, never once have I heard anyone care in the least about the watt-hours consumed during the brew process. "I really wish I could drink coffee at room temperature all the time and save a penny on electricity while doing it!" Someone will do the math, I'm sure it's not exactly a penny.

TL;DR: Aiming for a high-volume industrial goal, tone-deaf to coffee enthusiasts.

by emptybits

6/16/2026 at 5:43:36 PM

Actually, heating and pressurizing is limited by how much juice your electrical installation can pour out.

by econ

6/16/2026 at 9:25:48 AM

The crema looks like terrible, more like Nespresso, and having the coffee warm is kinda important.

But perhaps this can be used in the instant coffee industry or something.

by abujazar

6/16/2026 at 9:28:14 AM

>But perhaps this can be used in the instant coffee industry or something.

As stated in the article, the whole point is for use in ready-to-drink coffee manufacturing.

by elil17

6/16/2026 at 9:37:34 AM

For certain styles of coffee, crema in espresso is not necessarily desired — it typically has a high concentration of more bitter flavor compounds.

If you're drinking light, floral and acidic coffees, it's been relatively "trendy" recently to skim the crema off before drinking it.

I don't bother with that, but pulling two shots and removing the crema from one of them and trying them side by side is an interesting sensory experience — I'd encourage you to try, at least once!

by klausa

6/16/2026 at 10:02:02 AM

In that case I'd say espresso is not the right brewing method : )

by abujazar

6/16/2026 at 10:06:14 AM

Fully disagree, but I understand that perspective.

by klausa

6/16/2026 at 9:37:03 AM

Could be useful for mass production of espresso-based drinks (like the ones sold at convenience stores), and possibly various foods like Tiramisu.

An average coffee shop's espresso machine might use $200/month of electricity, so even though the percent saving (75%) is high, it's off a base that's small relative to other costs; possibly too small to be enticing.

by nomilk

6/16/2026 at 7:34:17 PM

It's funny people associate crema with good tasting espresso given the crema is the worst tasting part of an espresso

by cush

6/16/2026 at 9:00:08 PM

Yup. I bet they haven't tried scooping the crema and tasting it by itself. Since doing that, I now scoop and throw away the crema every time.

by david-gpu

6/16/2026 at 10:00:27 PM

I guess it's a matter of taste, and the quality of the coffee, but I love the crema. Personally I think removing it sounds a bit like picking the olives off the pizza.

by abujazar

6/16/2026 at 9:56:56 PM

This is completely false if the espresso is brewed with freshly ground and properly roasted beans with correct temperature and pressure. The texture of the crema also says a lot about the quality of the extraction.

by abujazar

6/16/2026 at 9:33:07 AM

> having the coffee warm is kinda important.

Cold drip coffee is a thing, done well a very nice thing.

by rstuart4133

6/16/2026 at 9:58:37 PM

Absolutely, and I enjoy a lot of cold brew, but it's not espresso.

by abujazar

6/16/2026 at 9:29:31 AM

It is the GPT2 of espresso. Looks bad but idea is sound. There will be a GPT5.5 later on.

by uberex

6/16/2026 at 9:26:39 AM

I like my Nespresso thank you very much.

by blcknight

6/16/2026 at 9:29:38 AM

And this is why you can't use "100 regular coffee drinkers" to judge the quality of the brewing method. Most people can't even taste (or care about) the difference between arabica and robusta beans or whether it's red or white wine.

by abujazar

6/16/2026 at 9:35:40 AM

Sure you can. You can absolutely use those 100 participants if your aim is to develop and market a process that can then be used to make a product for those same types of people. Samples generalise if your sample is representative, and in this case, for large commercial coffee extraction companies, third wave coffee aficionados are not in their target audience.

by tjcvirage

6/16/2026 at 10:07:40 AM

The product is moving into a different territory, though. I doubt these guys even know how to pull a proper espresso shot as a baseline for the test. I'm sure you can grind espresso coffee beans to a powder and just shake it until it achieves a flavor similar to espresso, but that doesn't mean the resulting drink can really compare to something that was brewed at the right temperature and pressure.

Technically you can also buy a bottle of grape juice from the grocery store, let it sit on the kitchen sink with a yeast lock for a few weeks and call it wine, and technically it even is, but it's also going to taste quite shitty.

by abujazar

6/16/2026 at 10:41:20 AM

> I doubt these guys even know how to pull a proper espresso shot as a baseline for the test.

You could just read the linked paper?

> Esp was prepared using a Sanremo Cube espresso machine. Brewing parameters were standardised following the supplier's guidelines: extraction time of 35 ± 3 s, pressure of 9 bar, and boiler temperature of 122 °C, with the corresponding group-head temperature of 94 ± 1 °C. A total of 21 g of ground coffee (GS = 2.6 ± 0.1; ∼262 μm) was placed in a ridged coffee basket and tamped using a constant-pressure tamper (MHW Flash Constant Pressure Tamper 2), applying 13.6 kg of force. The BR was reduced from 2 to 1.7 following the recommendations of the coffee roaster for better flavour (1 g of coffee grounds yielding 1.7 g of coffee brew).

1:1.7 is a bit short for my preferences (I like longer shots, usually aim for ~2.5); but otherwise that sure sounds like a pretty good double to me!

by klausa

6/16/2026 at 11:05:09 AM

You're right. But I drink my espresso hot, so I don't quite see how it can compare : )

by abujazar

6/16/2026 at 9:40:35 AM

I jumped on this at first as well. But to be honest if their target demographic is industrial production of coffee like beverages (like those Star Bucks soda can ”coffees”), well then it might not be so bad. I was thinking that a lot of flavour compounds of espresso breaks down quite rapidly while the drink cools, so the method of cooling all drinks to equal temperatures could be enough to skew the results regardless, but again for commercial coffee based soft drinks this is already the case. Headline is a bit misleading though.

by hultner

6/16/2026 at 9:35:18 AM

I like good quality coffee.

But I also need my coffee: I'll drink whatever quality coffee is being offered, as long as it's the best I can get that morning.

by kzrdude

6/16/2026 at 9:33:52 AM

Wine ruins the taste of coffee regardless of colour

by jemmyw

6/16/2026 at 9:36:56 AM

Considering the vibrations from those capsule machines it might not be so far off

by hultner

6/16/2026 at 10:01:10 AM

[dead]

by nryoo

6/16/2026 at 9:25:37 AM

Not even the baristas are safe. Technology really is coming for everyone.

by alansaber

6/16/2026 at 9:35:16 AM

When you thought that coffee snobs couldn't get any worse...

by elAhmo

6/16/2026 at 9:39:58 AM

...you discover frackuccino with cat processed beans: https://www.youtube.com/watch?v=rqw09I-BTvE

by defrost

6/16/2026 at 9:50:54 AM

Civet coffee is the best! The production method not so much sadly :( Maybe they can create an artificial cat stomach?

by thenthenthen

6/16/2026 at 8:13:28 PM

Trung Nguyen did that:

https://www.vice.com/en/article/a-vietnamese-company-is-brin...

Seemingly as early as 2010:

https://en.wikipedia.org/wiki/Trung_Nguy%C3%AAn#Weasel_and_L...

by ValentineC

6/17/2026 at 9:40:51 AM

Ok i NEED to check this out. Thanks for the articles! (Wtf basically kopi luwak was created through colonialism? An even more cursed product now wow

by thenthenthen

6/18/2026 at 12:43:39 AM

I don't get kopi luwak though.

I assume that such coffee is good because the civet cat has taste for good coffee cherries, not really because of the digestive enzymes or whatnot.

by ValentineC