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Cold brew coffee in 3 minutes using acoustic cavitation

unsw.edu.au

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Re: Cold brew coffee in 3 minutes using acoustic cavitation

#21

Post by iancmceachern »

triceratops wrote: post #14
peteforde wrote: post #13

Funny thing is that I'm currently drinking cold brew that I prepared on my acoustic cavitation brewer. It's called Osma Pro. The company that made it sadly did not survive, and they took a lot of heat (no pun initially intended) for the price point and various complaints about how it worked. https://www.engadget.com/osma-pro-cold-brew-coffee-machine-r... Luckily, mine works great and I like it a lot. I use it every m…

> The system connects a bolt-clamped transducer with the brewing basket via a metallic horn – transforming a standard espresso filter basket into a powerful ultrasonic reactor. Now it can be done without shelling out $695 for a dedicated machine. That's progress. I wouldn't be so dismissive.

But you have to shell out $10k for a commercial ultrasonic welder from Branson, etc. Just the horn they show in the paper probably cost $6k to make.

I wouldn't be too dismissive.

Re: Cold brew coffee in 3 minutes using acoustic cavitation

#22

Post by sharpshadow »

dahart wrote: post #17

Recently I discovered that many coffee shops, maybe half in my sampling of a couple dozen in different cities, are selling cold coffee (brewed hot, then refrigerated) under the name cold brew, and even the ones that actually cold-brew them seem to be under the impression that it needs to be served cold. I was laughed at in one hipster joint for asking for a steamed or warmed cold-brew, and another one initially refus…

I think they mentioned that cold brew has lower acidity than hot brew.

Yes it’s agitation with the mentioned frequency. Technically it should move the grounded coffee particles back and worth and so extracting the components.

Re: Cold brew coffee in 3 minutes using acoustic cavitation

#25

Post by sharpshadow »

htrp wrote: post #12
showerst wrote: post #9

This is incredibly cool and I want to go build one, though it feels like that cutaway model of injecting the ultrasound from the side would lead to very uneven extraction. I also chuckled at graf about doubling the caffeine content, as if that's necessarily a good thing =). Those cheap HC-SR04 ultrasonic modules output at 40kHz, so maybe this is home-brewable.

I think the idea is that the vibration transmits through the entire filter. The question is whether it's geometry/frequency specific

It’s likly not specific one could reduce the cold brewing time by shaking the jar.

Re: Cold brew coffee in 3 minutes using acoustic cavitation

#26

Post by dahart »

sharpshadow wrote: post #22
dahart wrote: post #17

Recently I discovered that many coffee shops, maybe half in my sampling of a couple dozen in different cities, are selling cold coffee (brewed hot, then refrigerated) under the name cold brew, and even the ones that actually cold-brew them seem to be under the impression that it needs to be served cold. I was laughed at in one hipster joint for asking for a steamed or warmed cold-brew, and another one initially refus…

I think they mentioned that cold brew has lower acidity than hot brew. Yes it’s agitation with the mentioned frequency. Technically it should move the grounded coffee particles back and worth and so extracting the components.

Yes, they mentioned that cold brew has a reputation for being lower acidity than hot brew, but they didn’t measure the pH of the coffee they were testing using a hot brew process. They reported the pH of the normal cold brew and sonicated cold brew as both about 5.1.

For frequency, does it matter if it’s high or low frequency? I’m wondering if I can shake my cold brew for 3 minutes and get close to the same effect.

Re: Cold brew coffee in 3 minutes using acoustic cavitation

#27

Post by vallode »

dahart wrote: post #17

Recently I discovered that many coffee shops, maybe half in my sampling of a couple dozen in different cities, are selling cold coffee (brewed hot, then refrigerated) under the name cold brew, and even the ones that actually cold-brew them seem to be under the impression that it needs to be served cold. I was laughed at in one hipster joint for asking for a steamed or warmed cold-brew, and another one initially refus…

The paper[1] seems to imply agitation is exactly what this method is promoting: "Furthermore, acoustic streaming induced greater mixing and enhanced mass transfer during brewing.". I assume the 100W of ultrasonic energy would be pretty hard to reproduce by just shaking your cold brew container though!

[1]: https://www.sciencedirect.com/science/article/pii/S135041772...

Re: Cold brew coffee in 3 minutes using acoustic cavitation

#28

Post by daniel_reetz »

iancmceachern wrote: post #21
triceratops wrote: post #14

Earlier quoted context omitted.

> The system connects a bolt-clamped transducer with the brewing basket via a metallic horn – transforming a standard espresso filter basket into a powerful ultrasonic reactor. Now it can be done without shelling out $695 for a dedicated machine. That's progress. I wouldn't be so dismissive.

But you have to shell out $10k for a commercial ultrasonic welder from Branson, etc. Just the horn they show in the paper probably cost $6k to make. I wouldn't be too dismissive.

Also it will be punishing for pets and MEMs microphones.

Re: Cold brew coffee in 3 minutes using acoustic cavitation

#30

Post by triceratops »

iancmceachern wrote: post #21
triceratops wrote: post #14

Earlier quoted context omitted.

> The system connects a bolt-clamped transducer with the brewing basket via a metallic horn – transforming a standard espresso filter basket into a powerful ultrasonic reactor. Now it can be done without shelling out $695 for a dedicated machine. That's progress. I wouldn't be so dismissive.

But you have to shell out $10k for a commercial ultrasonic welder from Branson, etc. Just the horn they show in the paper probably cost $6k to make. I wouldn't be too dismissive.

It's a prototype.
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