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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

#6
This is awesome in an overengineered way, but if you want to make cold brew the normal way it's very easy. Basically you make it using a cafetière/French press/Bodum[1] using cold tap water in the fridge overnight (probably put some cling film over it), then press it and run it through a drip filter. The secret (if there is one) is to use fine ground coffee like you would use for an espresso rather than coarse ground (like you would use for a normal drip coffee or French press). It's very easy and very lovely. Just don't skimp on coffee.

More detailed recipe here https://www.uncarved.com/articles/cold-brew/

[1] UK/US/French name but you know the thing with the plunger

Re: Cold brew coffee in 3 minutes using acoustic cavitation

#7
Interesting, I wonder how that would compare to recirculating water through the coffee grounds through a filter.

It does say the ultrasound generates 'micro-jets with enough force to pit and fracture the coffee grounds', so I assume that the ultrasound would work better?

There also seems research in using ultrasound in artificial ageing of whisky/spirits.

Re: Cold brew coffee in 3 minutes using acoustic cavitation

#8
It's really just a matter of mindset -- Many things go faster if you chuck them into a microwave or a sonicator :) I'm definitely going to try this out with cold brew in a cheapie bath sonicator. The thing here is like a big ass probe sonicator butted up against an espresso portafilter which is probably a bit louder than a loud steamer

Re: Cold brew coffee in 3 minutes using acoustic cavitation

#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.

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