Cold brew coffee in 3 minutes using acoustic cavitation
unsw.edu.au
unsw.edu.au
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.
It comes out lukewarm, hovering somewhere between room temperature and minutes-old vomit. If I want it hot, I microwave it. If I want it cold, I add ice. If I want a cold latte, I add milk. If I want a hot latte, I'm in the wrong house.
It costs less than $1 for a quad shot. It provides caffeine or at least a close-enough placebo effect. What more could an old, washed-out dev ask for?
I feel like my morning coffee is the one part of my day that I can control. You bet I’m gonna take my time and make it enjoyable.
And for people thinking you need some $$$ machine, even the most pretentious experts agree that pour over is about as good as that style of brewing can get (IE not something like espresso). A hand grinder and plastic v60 will get you to the point you're not limited by the equipment. The biggest expense is the beans themselves, and that's as much a taste thing as anything else.
But I guess like any hobby you there will be people selling you all kinds of things at any price people are willing to pay - maybe it makes it a bit easier, maybe a bit quicker, maybe it looks better on your counter. Maybe it gives you something a bit different and unusual. But none of it gives you better coffee.
The Faema e61 Legend isn’t quicker or easier, but damn it is pretty.
And that makes the coffee better. It’s also an effective space heater.
https://www.faema.com/uk-en/product/E61-MONOFASE-ANNIVERSARI...
Well. Not GIVE. It's $20K.
Using my v60, the slightly longer brewing process has led me to cut down my daily intake to 1-2 (sometimes 3) cups from my previous 4-5.
As a parent with young children, finding time for myself is a rare luxury, even going to the toilet isn't the private sanctuary it once was. Yet, on weekend mornings, I steal away 10-15 minutes to focus on brewing my coffee.
I'm not overly precious or meticulous about it, but the result is a richer, more flavorful coffee. The act of brewing itself becomes a calm and relaxing ritual as I watch the water soak into the coffee grounds and the aroma fills the air.
And its just a good way for me to start the day, before whatever madness and challenges my kids are about to create.
Spend 20% in effort and/or currency to get 80% of the optimal result. Spending the other 80% to get another 20% gain is rarely worth it.
Many relaxing things are part ritual. I like your thought process.
Friend of mine had a similar issue where his parents were wine people and, ever since he could drink, taught him how to pick good wine. Except he realised he does not want to pay that much for alcohol so he now just sticks to beer.
e.g. I used to drink any old instand coffee, then I found Douwe Egberts and strongly preferred that for a few years, then I started making pour-overs with pre ground coffee in a v60, then I found a better grind/roast/etc of the beans which is my go-to - now I drink 'real' coffee black and can only tolerate instant if it's adulterated with milk and a little sugar.
I'm trying to avoid making the jump to pulling my own espressos, it looks like way more fuss than the pour-over...
- Turn it on to heat up - Grind the beans - Weigh the grounds - Fill, tamp, and attach the portafilter - Start the infusion - Remove and dump the grounds - Clean the portafilter
It's a $600 electronic device, not a simple funnel and filter, but it's not a fussy process.
> now just sticks to beer.
Guess he's lucky he hasn't tried good beer ;)
Except that people who think they can "pick good wine" actually can't (there have been studies, too lazy to Google), and for the most part quality and price aren't correlated.
Luxury beliefs and all that.
The great thing is that it has zero maintenance and zero cleaning. I should probably do some de-limestoning (yes, there is a correct word for that that escapes me now) but I just avoid looking too closely.
My wife was considering a mid-range+ coffee maker where you would have two bean containers and make combinations. It cost a fortune (on my personal scale) and I told her that she lost her mind. And then did an Excel sheet where I realized that the two lines meet at 12 or 15 months...
Something about this description brings to mind the tea made by a Nutrimatic machine.
I’d not heard of it, because it’s not for plebes, like me.
Grinds and brews a perfect cuppa in about a minute.
I used to have a toddy maker, where you dumped a whole pound of ground coffee into a bucket of water, let it sit overnight, in the fridge, then you drained through a filter.
The resulting thick liquid was like really good instant coffee. You threw a bit into a cup, added hot water, and it tasted great.
The main issue that I would have, is maintenance. I would guess that it would need a fair bit of cleaning.
I just use a fairly basic Braun Melitta filter, and it does great.
About half as frequently, it'll also ask you to put in a descaling tablet. Similar process.
Beyond that, day-to-day, it can make about 8 shots of espresso before the grounds hopper is full. You just dump it and rinse it in the sink (no need for a thorough wash) and it's ready to use again. Less cleanup than a regular drip coffee maker (no filters to deal with, no grind dust to rinse/brush, no glassware, nothing to dry).
It's super convenient. The main downside is really just taste. I tried to do a blind taste test with my coffee snob friend (he's the kinda guy who measures everything down to the milligram and gives his grounds acupuncture before sending them to the spa). We used the same bag of beans, same water, same cups, etc. His came out with a layer of fine oils and sparkling foam. Mine looked like someone opened a dishwasher prematurely. We couldn't even get to the taste test part because you could smell the difference with your eyes closed. And I had a clogged nose that day.
Maybe the $3k Jura is different, but my janky little unit is definitely a poor man's machine – the hand-me-down Civic of superautomatic coffee makers. I'd buy it again in a heartbeat though.
Anyway, as others said ... good coffee they make, and some effort on cleaning they need (deserve).
On office coffee machines ... give me anything but syrup post-mix. Douwe-Egberts, I call you out. You make decent machines as well, stop peddling those abominations.
Reliable, repeatable, the coffee is not super duper excellent, but it's also not terrible. It's perfectly passable and it's free. My type of coffee.
It's kind of unavoidable that it's going to be expensive and higher-maintenance to be able to make espresso at home, so I simply don't. Not worth it for me when I already have access to high-end espresso machines at work 5 days a week.
If you have an office where the machine makes 100+ coffees it makes perfect sense. In a domestic setup it makes 0 sense.
You can get Juras for pretty cheap if you go bargain hunting. There are also other similar but cheaper brands. As a category, they're called "superautomatic espresso machines". I don't know why they're not more popular, but it's been a total game-changer for me.
I got my Jura A1 (their discontinued base model) used, third-hand re-refurbished, a decade ago for like $700. A chunk of change upfront to be sure, but since then it's consistently made like 4-8 shots of espresso a day, every day. If reliable mediocrity were a virtue, this thing would be the patron saint of saints. And if a cup of store coffee were $5 (which is cheap nowadays), the machine pays for itself in 3-5 months. Best purchase I ever made.
The mediocrity disappeared. It produces a fantastic brew close to the quality of the shop where I buy the beans.
Before attempting all this, I ran an experiment. I had my shop grind the coffee one notch back from where they grind for their in-house espresso. Then I put that into the by-pass chute and brewed it. This confirmed to me that machine’s grinder was not getting fine enough.
If you grind truly as fine as you would for an espresso machine, you may get a very slightly better brew, but it will come with a 5% chance of clogging the machine and wasting the ground coffee. Best not to fly too close to the sun.
A friend who knows a few things about coffee stopped by not too long after I did this conversion and asked if I had bought new beans, because “this shit is top notch”. It was a revealing experiment about the importance of the grind.
It’s a fascinating machine to take apart. We’ve had it for 15 years and I’m optimistic it will just keep going. At this point my goal it see when the espresso counter will roll over back to zero.
From the sound of things, Soylent.
As a kid I used to dream about being able to photosynthesize. I'd love to never have to worry about food or beverage intakes again.
New unit of measure unlocked.
It’s the natural progression of most hobbies
YOLO, and no one gets it right on the first try anyway...
Not that interested though, so whatever.
Then it quickly caught on as a novelty, with nitro et al, and when I tell people I drink cold brew warmed I get looks of confusion or turned up noses.
But brew temp and serving temp are orthogonal.
1. https://www.baristamagazine.com/the-function-and-future-of-b...
Where I live we don't get a lot of hot weather, so drinking cold brew cold is strictly a high summer activity for me.
And if anyone doesn't believe this, challenge them to find a truly "iced" coffee. :p
Yes!!! I’m biting my tongue a little on how infuriating the process has been to ask cafes for warmed cold brews, but you’re spot on and exactly right. I’m baffled that so many people who sell coffee for a living, think they know a lot about it, and act like coffee snobs, don’t seem to understand what cold brew even is. (Or, in a few cases in my sampling I’m certain it was willful ignorance, laziness, because it takes a little more work and more space to cold brew.)
I will say that one of my local cafes understood completely and they’re happy to make hot cold-brewed coffee, and made me feel welcome for asking for it. One or two others were very good about it, but hands down the majority of cafes were a bad experience when asking for a warmed cold brew. Good luck to them, they’ve lost my business.
It might seem like a very simple ask, but I think many people working in those jobs have learned it can be expedient to just say “we can’t do that” and short circuit the interaction, rather than to attempt whatever it is, have the customer send it back, attempt it again and have the customer start insulting them for not being able to “get it right”. This is particularly the case if there’s any sort of line, where one person sending something back will make every other customer angry.
I’m not at all saying you are doing this yourself, just offering context on why you might encounter this reaction.
As in many fields, a fraction of people are kind of awful and unfortunately their behavior winds up shaping how many things operate.
That said, part of what I’m blabbering on about is that I think cold-brew served hot should not be considered off-menu, I don’t think that’s entirely fair. Since cold brew served cold is an assumption in the first place, it seems like hot cold-brew is (or should be considered) just as on-menu as cold-served cold-brew. It’s fine that the assumption exists, I just don’t understand the pushback when I specify warm. I feel like calling a steamed cold-brew off-menu is exaggerating, considering that a) iced coffee exists; b) steaming espresso drinks is extremely common(!); c) many cafes that make espresso drinks essentially offer all combinations of brewing process, coffee, milks of various kinds, and flavorings. It’s so crazy to me to get shit for asking for a steamed cold-brew when something like a Caramel Ribbon Crunch Frappuccino with an Affogato shot and extra espresso exists and isn’t even considered weird or extreme. Maybe some cafes are pushing back against customers with Starbucks expectations, but they still offer a selection like espresso, cortado, mocha, latte, americano, flat white, blah blah blah. It’s like Mexican food, there is a name for every possible permutation of grounds, water, milk, sugar, and heat. Given that they have cold-brew, that they have a steamer, and that serving hot coffee and steaming things are both standard every-day every-order kinds of things, I simply can’t understand why I’d get pushback even if I am asking for something weird. I’m asking for something weird that is completely and trivially doable.
Anyway, you’re right. I know I’m peeing into the wind just a little. It is what it is, which is why it’s a waste of energy to fight it or complain about it. :P
Light roasts came (back?) into style among coffee snobs a few years ago because it highlights the difference between different sources/regions/whatever. Ever since then, the former best coffee shop in my town has been exclusively producing sour, vegetal, under-extracted brews. The justified reaction to Charbucks among coffee snobs has produced an objectively worse cup of coffee.
Roasting well in general is already quite challenging and is a lot more than just arriving at a certain bean color or temperature. Vegetal flavors are very much a roasting mistake that's being passed off as an inherent characteristic of a light roast. Combine that with techniques better suited to brewing (or pulling shots of) darker roasted, and you have a recipe for a dull, astringent, sour cup.
That being said, a sour espresso shot is always possible regardless of dark the coffee is, so I'd argue it has a lot to do with a cafe owner's willingness to train themselves and their staff to work with lighter roasted coffee.
Anecdotally, this is something I've experienced in the USA more than in Europe. When I ask a question in store a lot of times I get the feeling that the person answering considers themselves an expert and quickly make claims that I know for a fact are false.
It's like in the USA saying "I don't know, but let me get someone who does" isn't allowed.
> It's like in the USA saying "I don't know, but let me get someone who does" isn't allowed.
Venti!
But TBH one can do that with better coffee, caramel sirup, some crushed ice from the fridge, and even spray cream out of a can for much less money, just not 'on-demand' and anywhere/anytime.
Also, too much (spray) cream and caramel in Venti amounts can't be that good for your body.
90% of the experience is looking cool!
Fractional gram dosing, multiple pours at different temperatures, timed switch from immersion to percolation, and benchmarking different filter papers has a _measurable impact_ on my coffee.
And I have the data and refractometry measurement data to show it.
... Admittedly the refractometer was expensive, and incorporating it into the routine is complex and not very intuitive.
I can also assure you that I don't look cool while doing it.
Wouldn't it be a better term cold-brew or something like that?
I've found it a nice way to play with the style without investing the money and space. Still want one of those towers if I ever see them cheap though.
[1] https://puckpuck.me/ - no connection, just a customer.
https://www.amazon.com/Toddy-THM-Cold-Brew-System/dp/B0006H0...
He could even double down and make Breaking Bad references around the shop, since thats what this makes me think of.
I'm guessing it's not in Florida, or I would ask you for the address. He should at least get a window into that backroom installed or something to that effect.
I remember being really interested in a cup of Kyoto-style one day, only to be told to make a reservation and come back tomorrow... it was worth the wait.
> Fast forward 14 years. An acquaintance working and living in Japan went on holiday and discovered a bar with this exceptionally beautiful rig for the preparation of Viennese Triple Cold Extraction Coffee. Upon sampling this, he felt that, and I quote, “I could see colors that weren’t in the visible spectrum, and could vibrate through walls.” I looked at this I said to myself, “Hey, you’ve got enough virgin laboratory glassware lying around the house that you could probably build something like that.” Probably several somethings, actually, but that’s beside the point.
It has a picture of the original glassware in Japan and his first iteration in the kitchen. A sibling comment links to Yama glass ... which is out of Taiwan. The similarities might not be coincidence.
Likely the Yama cold brew tower [1].
[1]: https://prima-coffee.com/equipment/yama/yamcdm25sbk-yama-pp
And pricing is a completely orthogonal and obtuse concept too. Cold brew is putatively low effort and low cost. Just let coffee grounds soak in water overnight and you have cold brew. But it's often charged more than regular coffee or espresso-based drinks, which a) use more expensive equipment b) need more skilled operation c) more material [milk etc]
Cold brew takes more refrigerator space, which is relatively inflexible. Since it brews overnight, you have to put aside enough fridge space for all the cold brew you expect to sell that day. Contrast with regular coffee, which you make largely on-demand, with only the coffee beans to store overnight, on a shelf. So raising the price might be the sensible thing to do, to discourage purchases and/or pay for the extra refrigerator space.
In a coffee shop you need to prepare way more coffee, you need the space to store it cold over night, so I would say the higher price is understandable.
The consumer decides the price that is acceptable for the good - the cost of that good being higher or lower just changes the viability of the product and the bottom line from selling it. So it makes tons of sense that given two similar products that consumers will pay a similar price for that companies would prefer to sell the one that costs them less.
Not to discount the rest of your comment but it's a mild irony here for you to add the 'hipster' qualifier to a coffee place when you ask for steamed cold brew
I’m asking for cold brew because my esophagus gets inflamed with higher acidity coffee. I used hipster not as pejorative, but to indicate this is a cafe that claims to, and should, know the difference between cold brewed and hot brewed coffee. In fact, I’m certain the owner does know the difference and the snarky barista who refused to help me that day does not. First she said, “Uh, we call that a drip.” When I offered the acidity reason and that it’s my doctor’s recommendation, she replied with “it’s not on the menu”. Cold brew was on the menu.
I think of myself as very knowledgable barista and this is first time i am hearing this. I checked usual resources like James Hoffman and nobody is even mentioning heated cold brew. So its very niche and sounds more like something from camping.
I believe you that health wise its for some people better. But cold brew overall is not that popular with coffee fans because the coffee is underexttacted - it tastes ok but you will get more flavours using hot water. Its kinda waste to use high quality coffee on cold brew. But thats where i personally like cold brew - with lower quality coffee it can taste better than hot extraction.
Cold brew was in fact on the menu, and it is in a lot of cafes. Arguing that cold brew is not popular and not ideal is a straw man here, and is also very debatable given that it’s widely available. That cold brew was available and on the table is a given, regardless of what you think about it.
You say you are a knowledgeable barista. Can you handle steaming something? I’m pretty sure you can, and that it would be 100% trivial, right? I didn’t ask for some unknown or mysterious or strange process. What I asked for is pour the cold brew they were selling into a cup, and steam it. Exact same process as the milk half of a latte. Why, exactly, does it matter what’s being steamed, and why does that deserve scorn when requested? Why, exactly, does it matter if the request seems unusual? Who cares, when you and I both know it can be done without even thinking?
The good cafes do it happily without batting an eyelash, and don’t complain about it being weird, because if you think about it at all, heated cold brew might be uncommon but it’s neither weird nor hard to do at all.
If that's correct, then warming the coffee again to that temperature would again speed up the release of volatile compounds, though what effect that might have on flavor is anyone's guess.
Acetic acid is sour. Alkaloids are bitter.
I won't pretend to know the science behind it, or perhaps I warmed it differently than what the parent poster does, but I definitely sympathize with the barista's hesitation in his story.
Warm Coke is disgusting; freezing cold Diet Coke is the nectar of gods.
however HOT cola (which can happen if you leave it in a car) is physically painful because something weird happens to the bubbles
Cold brew needs a new name or it will likely fade away over time.
As someone that greatly prefers coffee brewed cold and served on ice, I hope it doesn't fade away, because without it I have a lot less reason to get coffee out as opposed to at home.
If it were called something else, maybe there wouldn't be this level of confusion, or people couldn't get away with the cheap/lazy way of just serving yesterday's leftover hot coffee as "cold brew."
[1]: https://www.sciencedirect.com/science/article/pii/S135041772...
Since you could presumably put 2 of these in parallel and have 2x100ml cups in 2min with 200W without changing the recipe (or 1 cup in half the time), this seems pretty scalable with increased cost and area.
Unagitated cold brew is in the 10hour region, but with agitation/pump through it seems like you can do 8 cups in 20min which is almost as fast as the cavitation method. I suspect the grind size starts having really big effects here.
The ultrasonic cleaner is always stashed away somewhere safe for its once-a-year use ... I think can't resist to experiment.
I'd disagree though that it's "extreme". There are local chains in my area (Midwest - US) that offer a variety of hot cold brew drinks that are quite popular offerings. I was pleasantly surprised when I ran across this more than a year ago. But I still do run into a number of coffee shops where baristas fail to understand the difference between cold brew and an iced coffee. There's really no comparison when you're explicitly looking for cold brew. It's also often hard to find available in the winter months in my region. Not sure why, but to me that's akin to pausing ice cream sales because there's snow on the ground. Just because it's a cold drink doesn't mean I don't drink it during cold weather.
The main problem is that I love the flavor of coffee, and I feel especially jealous on a Saturday morning when I can smell it but can’t drink it. Secondary problem is adjusting to a consistent caffeine level without getting headaches.
Wouldn't try to randomly talk a barista into making one, but if you see them on the menu at a shop or have an espresso machine, they're pretty neat.
Video on them: https://www.youtube.com/watch?v=tD_4hOg_SWU
I know a lot of coffee nerds and cold brew is disdained for not extracting enough flavors. This is just someone who never adapted to the world hoping the world will adapt to them.
There seems to be two ways to cold brew coffee.
The more traditional method (like in the toddy system) uses paper filters, and the newer method uses reusable metal filters.
They are slightly different. the paper filters remove the oil, while the metal filters let it through. I suspect this might have flavor/aroma effects.
I also read because of the oils, the metal filter method is higher on cholesterol (if that makes any difference to you)
I've also seem drip cold brewers at some coffee shops that probably let the oils through. There seems to be a container of ice at the top, it melts and drips on a glass container of coffee and that drains through a circular glass thing (looks like a slinky) into an output carafe.
> higher on cholesterol
Google tells me:
> Though brewed coffee does not contain actual cholesterol, it does have two natural oils that contain chemical compounds -- cafestol and kahweol -- which can raise cholesterol levels. And studies have shown that older coffee drinkers have higher levels of cholesterol.Since it's DIY I have no one to argue with about how to serve. I have stopped making cold brew for the most part because it seems to require more coffee beans than hot brew. Maybe I'm doing it wrong. I don't have a "cold brewer" and just add water to grounds in a glass jar with lid and shake when I walk by before filtering it the next day. Neither have I compared the cost of electricity for drip vs. the extra beans for cold so I don't really know which is more cost effective.
https://rpdillon.net/recipes/new-orleans-cold-brew-coffee.ht...
Serving temperature affects flavor, too, of course. Darn near everything does.
See, for example: https://www.mdpi.com/2304-8158/9/7/902
I have a bunch of kegging equipment that I don't use anymore because I've lost my taste for beer, and I keep wanting to see what happens if I use it to make cold brewed coffee under a bed of CO2.
Also, y'know, coffee on tap at home.
AFAIK the aromatics in coffee are quite volatile so what you end up with is like "grain soup". The coffee tastes more like the roast than the actual coffee.
After trying it, I liked it a lot... I always drink coffee over ice (usually with a lot of cream and sweetener), as I'm not so much a coffee fan as a caffeine consumer a few times a month. I like the more mellow taste of cold brew.
Using ultrasonic will do it even faster, but since ultrasonic underwater induces cavitation bubbles, it's much more violent.
Ultrasonic has been used for dermal infusion quite successfully, but it is....painful, as bubbles are exploding against your skin.
I would presume the same to be for the sonic coffee. Agitation speeds up the process, until cavitation occurs, where it becomes more violent
Yes it’s agitation with the mentioned frequency. Technically it should move the grounded coffee particles back and worth and so extracting the components.
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.
I'm not certain how I'd warm it up. I suppose it could be poured into a clean frothing pitcher and steamed directly, I'd somewhat worry that might dilute the flavor of the coffee.
I don't reckon someone's going to want me to microwave their cold brew, but it certainly seems like it'd be the quickest way to do it.
Most cafe workers get into flows of orders. Lattes means you always pump syrups into the cup, start the pour, then steam milk. Cold coffees usually means you ready the cup (syrups, milk) and pour the cold brewed coffee onto it.
Warming the cold brew totally breaks that flow, and is why it would be unexpected.
Hope that perspective helps. I do want to try it now though! I could imagine it being pretty good.
If hot cold brew was common you wouldn't pay extra for it
For each experiment, she made 2 cups of coffee, using 1 scoop of grounds (0.25 oz) to make a pour-over with 8 oz water heated to 200 degrees Fahrenheit for each cup. In one of them she added 1/16th teaspoon (which is a tiny pinch) of baking soda to the grounds before pouring the water over them. In the other cup, it was only grounds with no baking soda. She said she could see the water foaming in the cup with baking soda. She reported that there was no noticeable negative flavors at all, no hint of baking soda taste, the coffee made with baking soda was as good as the control, perhaps slightly better because it was less acidic. For the pH measurement, she measured a pH of 6 for the normal coffee and a pH of 8 for the baking soda added cup — it actually made the coffee slightly alkaline! PH of 6 sounds like a pretty weak coffee, I was usually getting a pH of 5 IIRC. PH strips are a pretty blunt measure and don’t give you fractional pH values, but she showed me the strips and I can confirm her conclusion. The 2nd experiment was the same setup, and the result was identical.
When I read your comment earlier, I thought it was a good question, but assumed baking soda would change the flavor negatively. I’m surprised to hear that it totally works, so I think you have a good idea. I might even consider making this my routine if it works that well. Now I’m curious if you can sprinkle in a tiny pinch of baking soda into an already brewed coffee and reduce acidity without damaging flavor…
There are low acidity beans, and as I just found out additives to counteract acidity that won’t compromise the flavor, such as baking soda. I guess I might head more in that direction and stop worrying about cold brewing.
Here is more info on hot/cold https://www.researchgate.net/figure/pH-values-of-six-coffee-...
Hot brewed coffee starts to taste bad after a few hours if you let it go cold, cold brewed coffee tastes differently from the start, but won't develop that bad flavour even after a week in the fridge.
The key for a good cold brew is however that the bean/roast is of very good quality. And it is quite simple to make. The way I do it:
1. Grind coffee coarsly and put it in a glas jar that can be closed. The amount of coffee can be adjusted quite freely, but I'd go with one fourth/fifth of the volume of the jar. More bean = more concentrated coffee.
2. Add cold water and stir
3. Put in the fridge and stir at least once in the morning, once in the evening.
4. After ca. 24 hours you can run the whole thing through a coffee filter to extract the coffee. It is also possible to reuse the coffee-sludge once if you add some fresh beans.
That is not too complicated and worth a try. Please avoid pre-grind cheap coffee for this, It will taste like bullshit.
The same things happens with beer. Many traditional and craft beer styles are intended to be served at a higher temperature than what it will be right out of the refrigerator, and you really do get more (and, to my palate, better) flavor out of them if you let the bottle warm up on the counter for a while before you open it.
If you let coffee and water sit for long enough, all the compounds that can be extracted, will be extracted. But those compounds will also start to break down over time. Heating and oxidation accelerates the breakdown.
When you go to taste coffee, the compounds in the coffee either expand or contract depending on the temperature, and solubility. So the temperature you drink it at, along with water concentration, determines the flavors. (Flavor is actually aroma, taste only has 5 basic senses)
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 morning.
Takeaway point: maybe Google your idea to see if other people have also had it before describing it as new.
Now it can be done without shelling out $695 for a dedicated machine. That's progress. I wouldn't be so dismissive.
I think the commenter you're responding to was calling out the use of the word 'new' (which is used five times in the article) to describe the process, when it's evidently not new at all. The commenter didn't say anything about the price point, and neither does the article.
I wouldn't be too dismissive.
I expect they used something like these:
https://www.emerson.com/en-us/automation/branson
You cannot 3d print anything in the ultrasonic chain, they need to be machined from specific metal, that's why the horns cost so much.
We're talking about coffee here...
More detailed recipe here https://www.uncarved.com/articles/cold-brew/
[1] UK/US/French name but you know the thing with the plunger
I use a $5 nut milk bag instead, it lets me brew way more at once; I do 1/4 kilo grounds with 2 liters of water. It also has the benefit of reducing cafestol, which makes it healthier, according to some.
I often filter my french press cold brew after-the-fact with a paper filter to achieve this.
Huh? I don't plunge until after it brews, and the purpose of the plunge is just to keep the water out of the grounds from that point forward, to (essentially) stop the brewing process. Or so I thought
Anything that gets more small particles past your filter will add to your coffee's bitterness. This can happen when using a ground coffee that has a lot of fine particles, or if you agitate when you pour/plunge.
But I realized less disturbing is better, and I started barely using the plunge - just to catch grounds when pouring.
After a while I went back to pour-over. The flavor is so much better - French press is now used for loose leaf tea and I have a lot more fun plunging.
Maybe the Coffee Lit Review podcast will cover this, but honestly it's not that interesting. Cavitation has already been done many times.
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.
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.
[1] https://www.engadget.com/osma-pro-cold-brew-coffee-machine-r...
(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.)
We need Lance Hendricks or James Hoffman to do experiments and determine the best temperature.
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.
It also looks like a PDF of a paper, so presumably they have a paper that talks about the geometry/frequency interactions.
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.
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.
Does the ultrasonic tub enable better extraction at lower proof or are you using it purely to speed up the maceration process?
For comparison, I also have a Soxhlet apparatus. As the extraction is boiled in the bottom with the recycling solvent it does not make the best flavours but it's the fastest way to get stuff like cinnamon.
Between a longer time, soxhlet and ultrasonic, the ultrasonic gives flavours as smooth as a longer time without the wait. (The ultrasonic bath heating up is still a problem so I have to cycle it).
Time beats both.
I think a short path soxhlet maybe be as good. My setup is a bit fragile for a good vacuum though.
It actually tastes pretty good. Most of the acrid taste from (hot) instant isnt there
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.
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. Now pour over ice.
Can also do this over night for larger brews in the fridge (non freezer).
This is as close as I could get to a Starbucks iced coffee that isn't watered down and still has bite.
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
Is this a joke?
Its unpleasant.
https://dailycoffeenews.com/2023/11/16/howard-schultz-part-o...
Of course, it's an attempt to be the next Keurig/Nespresso.
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.
And yes, ultrasonic cavitation will break apart the grounds very thoroughly. Think a jewelry or denture cleaner.
If you want speed, get a fully automatic machine. Ideally with a timer so your coffee is ready when you wake up.
How will cats feel about that high-pitched noise?
https://old.reddit.com/r/coldbrew/comments/ob0gzg/cold_brew_...
You can also sous vide coldbrew coffee for faster results than traditional coldbrew. But at that point is it still technically coldbrew? Maybe warmbrew is a better term for it.
I sense a new term making its way into coffee marketeering...
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.
The inventor of the aeropress shared this tip. Here's his recipe:
https://www.youtube.com/watch?v=oUD6HxDnlwI&t=56s&ab_channel...
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*!