Researchers at UNSW Sydney have harnessed the power of ultrasonic sound waves to make espresso-strength coffee with room temperature water, cutting energy use by up to 75%.
this post was submitted on 16 Jun 2026
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Why the fuck would I want a room-temp espresso?
When hot days and you need to wait for it to cool down and add ice. All those Starbucks frappucinos with this tech will save the world.
Hot day? What's that?
Yeah I don't know what these fellas are talking about, this is the coldest summer of the rest of our lives
It’s like a hot dog.
"Although the researchers say their new system could be relatively easily developed into an automatic coffee machine for home users, the biggest opportunity is likely to be for large-scale commercial producers of coffee-based drink."
They say it in the article what it is for...
Cold brew
I wonder if this method produces less acidic coffee, like cold brewing does?
while ultrasound can do some weird things, article says
Their research, published in the Journal of Food Engineering, included blind taste-testing experiments which showed that their ultrasonic room-temperature version of espresso was undistinguishable from coffee shots brewed in the traditional way.
Except cold... Why would someone drink a cold expresso? It just seems kinda gross, then again, I'm not a fan of putting cheese in my coffee either (different strokes for different folks I guess).
Espresso is often served over an ice cube in Spain, and it’s fuckin great, to use the technical term. If it’s hot, I’m all for the cold and tasty
At that point I would think it's more of an americano (espresso and hot water) that's been mishandled, but that's just my opinion. I've never been a fan of cold coffee though I always end up drinking some before I'm done in the morning.
You’ve clearly never had it. You neck it immediately, it’s an espresso shot, but instantly cooled by flowing over an ice cube. It’s not watered down any significant amount, you don’t wait for the ice cube to melt, you’re missing how much latent energy there is in the change between frozen and liquid in ice. There’s plenty to cool a small shot without melting the whole thing. It keeps the sweetness and even most of the texture of the original shot, it’s just not hot, it’s worth trying
I'd probably give it a shot if I end up around one (I thought for sure horchata would be gross but then was pleasantly surprised). It just seems odd to drink coffee cold, I've never liked coldbrew or the cold ones from Starbucks/Costa.
Who tf puts cheese in their coffee
Haha... That was my honest response when my wife told me about her coworker doing it. I believe she was Columbian and it was just the way she liked it.
Doesn't count until James Hoffman reviews it.
Not sure how I feel about this. There is no real logic to my resistance on the idea, but I have some.
I don't really get it to be honest. It's pretty pointless if you don't want room temperature coffee, or no.
Perfect for iced coffee though
Better. Perfect would be using chilled water. I'm on a limited connection right now so I can't investigate, but I'm curious to know if they tested.
probably can be done, but ultrasound irradiation itself will warm up coffee a little. if all of it goes to heat, then it's extra 20C or so so you'll have to cool it down afterwards anyway
They're talking about commercial scale coffee products and coffee flavoured products (bottled coffee drinks, instant coffee, etc.), where a reduction of 75% of the energy consumption could not only be very profitable, but also helpful in hitting environmental targets. Coffee is already a bit of an environmental nightmare when it comes to water usage in farming, so lessening the impact of commercial coffee is definitely a plus.
if all that energy is used to boil water and we're cutting that energy use by 3/4 then it's saving 70Wh (not kWh) per litre, or 70kWh per cubic meter. that's not much
When you're dealing with thousands of litres per hour, it's a fair amount.
You can heat the water afterwards. A lot of the heat in the hot water is lost in the beans. This might never have an application at your local coffee shop, but for canned coffee it will make a dramatic difference in profitability.
A coffee shop is still going to have a regular espresso machine running all the time.
Did you use reading comprehension as a dump stat? You just used different words to say what I said.
One day my wife at McStarbucks:
Yes, can I have a grande pamuchino with double cherry smoothie foam over a choco layer at 47KHz please?
I like to think the person who revealed this to the public was like "Good news, everyone!" like Prof Farnsworth
It's never good news
Piezotransducer? As in the little thing that makes electronics beep and buzz?
Yeah basically, but at a much higher frequency since it's ultrasound. Human hearing tops out at 20khz, and this would be close to 50khz
I found one for sale that does 40k that has the same form factor as the one shown in the paper. I almost want to make a high-speed coldbrew system but I don't expect it'd be worthwhile for the coffee, only maybe for the fun of building it.
Lol worst case you can convert it to an ultrasonic parts cleaner
Not quite. Worst case scenario is I make a torture machine for any dog, cat, and maybe other non-human animal in the area.
Finally
/s