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 refused my request to warm it up saying that would make the coffee extremely sour. (It didn’t) Oh, and at least one other, maybe two, said they couldn’t warm cold brew (in view of both a steamer and microwave) or would have to charge extra (while someone’s cheaper latte was being steamed).<p>Reading the paper, it’s not clear whether their cold brew has lower acidity (higher pH) than the same coffee hot brewed. It does say that the sonic-brew has the same pH as the normal long-steep cold brew. I’m also curious if this cavitation/sonication brewing process is basically agitating the coffee, or doing something different, and how different it is from manually agitating a cold brew compared to letting it sit still for hours.
Funny thing is that I'm currently drinking cold brew that I prepared on my acoustic cavitation brewer.<p>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.<p><a href="https://www.engadget.com/osma-pro-cold-brew-coffee-machine-review-131552500.html" rel="nofollow">https://www.engadget.com/osma-pro-cold-brew-coffee-machine-r...</a><p>Luckily, mine works great and I like it a lot. I use it every morning.<p>Takeaway point: maybe Google your idea to see if other people have also had it before describing it as new.
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.<p>More detailed recipe here <a href="https://www.uncarved.com/articles/cold-brew/" rel="nofollow">https://www.uncarved.com/articles/cold-brew/</a><p>[1] UK/US/French name but you know the thing with the plunger
Or you could use a (quite affordable) ultrasonic machine designed for gentle cleaning of jewelry, dentures, glasses..<p>I've used one to extract fragrance from biological material for an artistic project[0], and it worked really well. Instead of having to wait for a few weeks for a tincture to finish, you put the same tincture (alcohol and material you want to extract fragrance from) into a plastic bag for just 15 minutes. Sure, it smells not quite the same, but the speed is often worth it. I've even heard about some guy trying to turn vodka into whiskey with an ultrasonic machine and wood chips.<p>There are quite a few ultrasonic machines on the market. I've tried EMAG and multiple Chinese no-name machines that are just as powerful but cheaper. Sadly the no-name machines are quite a bit louder - you can't stay in the same room while it's running basically. Still, they all work well for this kind of fast and dirty extraction.<p>[0] <a href="https://rybakov.com/blog/smelling_cz/" rel="nofollow">https://rybakov.com/blog/smelling_cz/</a>
A few years ago there was a crowdfunded instant cold brew machine based on acoustic cavitation called Osma.[1] I don't think it's still in production. I met the founder during testing at Chromatic Coffee in San Jose, and took delivery of one of the first units. Cool concept, but it didn't work very well<p>[1] <a href="https://www.engadget.com/osma-pro-cold-brew-coffee-machine-review-131552500.html" rel="nofollow">https://www.engadget.com/osma-pro-cold-brew-coffee-machine-r...</a>
Ooh an excuse to upgrade some homelab equipment :-)<p>(My preferred "weird" coffee is sous-vide: 125g/liter, 2h @ 150f - so you don't leave as much flavor "on the table", but by not getting near boiling you leave more of the bitter compounds behind. Refrigerated but served iced or warmed with boiling water, to taste.)
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
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.<p>I also chuckled at graf about doubling the caffeine content, as if that's necessarily a good thing =).<p>Those cheap HC-SR04 ultrasonic modules output at 40kHz, so maybe this is home-brewable.
"Ultrasounds can be applied to several areas across the food industry including drying, extraction, emulsification and crystallisation – making the process faster and more efficient.", .. I think they have the tense wrong. It should read "Ultrasounds are now commonly applied .."<p>People have been doing this sort of thing for years. I have an ultrasonic tub for extracting flavours into ethanol. I didn't invent it, people were talking about it years ago on the forums on this stuff.<p>Maybe they don't have internet over there at UNSW. They can come over and borrow mine for a bit of a search. I am just a few ks away. Or go to that internet cafe in Kensington in the next block.
As someone who makes cold brew every day, this is one of the two approaches I've considered to speed things up, the other being one of those magnetic stirrers they have in chemistry lab.
However, after careful consideration, the real low-hanging-fruit here is the time it takes to grind the coffee, load it, fill the water, clean the filter, and rinse the jar. If a cold brew machine could automate these steps (like some hot coffee machines do) you wouldn't care about making a cup in 3 minutes because you'd always have an automatic jar ready for you from 24 hours ago.
Hmm.. I didn't think to try my ultrasonic machine. Last time I made cold brew and got impatient, I just warmed it up to around 100F and put the whole thing in my vacuum chamber for a bit. Seemed to speed things up but I don't know. I don't brew enough to have a recent comparison. The result is pretty great though.
I discovered you can mix Nestle instant coffee with cold (charcoal filtered) water and it dissolves fine. Somehow the added sugar easily dissolves too. I also add heavy cream<p>It actually tastes pretty good. Most of the acrid taste from (hot) instant isnt there
Search for "portable ultrasonic washing machine" on Amazon/Aliexpress, looks like a hockey puck you drop into a bucket with water and clothes. Looks like the principle of operation is the same, just add a coffee filter.
Is their approach different from this one from 5 years ago? <a href="https://youtu.be/cO6-SL3bMZg?si=_pVdOLNdej2pjDnT" rel="nofollow">https://youtu.be/cO6-SL3bMZg?si=_pVdOLNdej2pjDnT</a>
I'm disappointed that their test didn't include a comparison to traditional drip coffee made using the same beans, then chilled to match the temperature of the cold brew.<p>I haven't looked into ultrasonic cavitation in years, but since it can produce enough heat and light to make some people wonder if it was a form of nuclear fusion back in the early 2000s, I feel like maybe it's affecting the flavour of the coffee at least as much as using hot water would.
Here's my iced coffee prep for those who like it strong with a bite:<p>Prepare a "lungo" via espresso by brewing through twice (or more) as much water through a single espresso puck. Don't do this over ice. Put the cup in the freezer. Depends on the cup (I use ceramic) but should be close to room temperature or slightly cold after about 30 minutes. <i>Now</i> pour over ice.<p>Can also do this over night for larger brews in the fridge (non freezer).<p>This is as close as I could get to a Starbucks iced coffee that isn't watered down and still has bite.
I'm guessing few on this board have heard an uktrasonicator in action.<p>I just showed to article to my mate, and he enthusiastically said we'll brew some... as soon as we leave the lab to break for lunch
It’s strange that they write this like it’s some new discovery when modernist chefs have known this for years and even developed “sonicators” for commercial use.
You can also make reasonable (not excellent, not terrible) brandy this way by putting vodka and oak wood shavings of a suitable kind into an ultrasound machine.
The longtime CEO/President of Starbucks recently invested in a Cold Brew startup called Cumulus which makes instead coldbrew via a $600 countertop machine.<p><a href="https://dailycoffeenews.com/2023/11/16/howard-schultz-part-of-20-3-million-seed-for-pod-based-cold-coffee-startup-cumulus/" rel="nofollow">https://dailycoffeenews.com/2023/11/16/howard-schultz-part-o...</a>
Interesting, I wonder how that would compare to recirculating water through the coffee grounds through a filter.<p>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?<p>There also seems research in using ultrasound in artificial ageing of whisky/spirits.
New startup idea: manufacture a hard-plastic spiky attachment, shaped like a tubular hair-brush that I can simply screw onto the base of my Sonicare toothbrush, then stand upside down into the brewing carafe of my Oxo cold-brew setup. The Sonicare's built-in 2 minute timer may have to be activated twice, for a full brew.
Why 3 minutes? Fancy ways of brewing coffee bring more value via their ritualistic part than via the final product. Same for smoking a pipe, it's the filling up and cleaning that matters.<p>If you want speed, get a fully automatic machine. Ideally with a timer so your coffee is ready when you wake up.
So, to simplify, we could take a large mason jar and attach to the bottom a magnet and wire coil attached to a power source, and just pump sound waves into a glass jar of water and coffee grounds. Effectively it's a speaker that holds coffee. Should have the same effect
Our espresso machine has been on the fritz for a while, but I barely miss it after discovering that a few oz. of TJ's cold brew with a splash of milk in the microwave for 30s is practically as good. I think warmed-up cold brew is one of my favorite life hacks.
I enjoy a good cold brew but it’s been a rare occurrence. It usually has a stale taste I assume is due to oxidation. I can see coffee shops using acoustic cavitation to make fresh batches throughout the day instead of one big overnight batch!
Was going to crack some joke about their work, but then realized that this tech is absolutely monetizible. Hook it up to, say, Nespresso marketing machine and this will sell like hotcakes.
<a href="https://en.wikipedia.org/wiki/Sonication" rel="nofollow">https://en.wikipedia.org/wiki/Sonication</a><p>How will cats feel about that high-pitched noise?
Technically interesting and possibly useful at an industrial scale, but I think I'll stick to my moka pot/french press setups. Both are good enough and easy enough for me.
This is a neat idea, since cold brew has a common criticism of an oxidized flavor due to its long steep time. A shorter steep could get you the smooth flavor without the oxidation
Ultrasonics seems like a heavily underused technology based on the little I know about it. Piezo elements are cheap too and you can get a lot done with them
Wake up yourself and all the dogs in the neighborhood at the same time. I want one.<p>I went through the obligatory Australian fascination with espresso and am well over it. It is a load of fetishistic bs and scalding hot coffee is disgusting. I buy bottles of cold brew from a local roaster and avoid the hassle.
Not to be that guy, but this works with room temperature water if you stir it for a minute as well. No need for "acoustic cavitation" for this to work.<p>The inventor of the aeropress shared this tip. Here's his recipe:<p><a href="https://www.youtube.com/watch?v=oUD6HxDnlwI&t=56s&ab_channel=EuropeanCoffeeTrip" rel="nofollow">https://www.youtube.com/watch?v=oUD6HxDnlwI&t=56s&ab_channel...</a>
<p><pre><code> The Doctor: It's sonic, okay, let's leave it at that.
Captain Jack Harkness: Disruptor? Cannon? What?
The Doctor: It's sonic, totally sonic. I am sonicked *up*!
Captain Jack Harkness: [yelling] A sonic *what*?
The Doctor: [yelling] *Coffee maker*!</code></pre>