Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

Making espresso with ultrasound

unsw.edu.au

Post reply on HN
Print view View original

21–30 of 94 posts

Re: Making espresso with ultrasound

#21

Post by hultner »

fabian2k wrote: post #13

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.

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.

Re: Making espresso with ultrasound

#23

Post by hultner »

blcknight wrote: post #7
abujazar wrote: post #5

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.

I like my Nespresso thank you very much.

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

Re: Making espresso with ultrasound

#24

Post by nomilk »

abujazar wrote: post #5

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.

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.

Re: Making espresso with ultrasound

#26

Post by klausa »

abujazar wrote: post #5

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.

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!

Re: Making espresso with ultrasound

#28

Post by hultner »

abujazar wrote: post #12
blcknight wrote: post #7

Earlier quoted context omitted.

I like my Nespresso thank you very much.

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.

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.

Re: Making espresso with ultrasound

#29

Post by fabian2k »

tjcvirage wrote: post #14
fabian2k wrote: post #13

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.

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.

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.

Re: Making espresso with ultrasound

#30

Post by klausa »

mzitelli wrote: post #3

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

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.

Post reply on HN