[HN Gopher] Cold brew coffee in 3 minutes using acoustic cavitation
___________________________________________________________________
Cold brew coffee in 3 minutes using acoustic cavitation
Author : ople
Score : 328 points
Date : 2024-05-07 12:46 UTC (10 hours ago)
(HTM) web link (www.unsw.edu.au)
(TXT) w3m dump (www.unsw.edu.au)
| skrunch wrote:
| Quick, someone let James Hoffman know!
| blkhawk wrote:
| I was just about to suggest he same thing
| brotchie wrote:
| Coffee fracking IRL
| doodlebugging wrote:
| Get yourself fracffiened.
| simondw wrote:
| Ah yes, with a delicious frackuccino.
| eps wrote:
| 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.
| seanhunter wrote:
| 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 cafetiere/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
| arijun wrote:
| If you use a French press for cold brew, be aware that the
| harder you press, the more bitter it will come out.
|
| 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.
| senkora wrote:
| > 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.
| hammock wrote:
| >the harder you press, the more bitter it will come out
|
| 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
| vincentrolfs wrote:
| I agree with your confusion, are we all talking about the
| same thing?
| i_am_jl wrote:
| Plunging pushes your coffee through the metal filter.
| Pushing harder pushes the coffee through the filter with a
| higher pressure. Higher pressure pushes particles past the
| filter more easily than lower pressure. Coffee particulate
| has a tendency to make coffee more bitter.
|
| 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.
| hammock wrote:
| I don't know anyone who's jumping up and down on the
| plunger or doing anything more than pressing it slowly.
| Have to imagine the coarseness/evenness of your grind is
| a 10x bigger factor in that regard
| NegativeLatency wrote:
| > or doing anything more than pressing it slowly
|
| I have a french press for camping, it's fine but when I
| want that first cup of coffee and it's cold and rainy
| outside you better believe I'm not pressing it slowly.
| dhritzkiv wrote:
| One thing I'll mention is that cold brew doesn't need to be put
| in the fridge to "brew". It can be left out on the counter at
| room temperature. As a result, this takes the brew time from 24
| hours to about 12 hours.
| anfractuosity wrote:
| 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.
| bethekind wrote:
| A YouTuber calls thought emporium tried out the whiskey method
|
| And yes, ultrasonic cavitation will break apart the grounds
| very thoroughly. Think a jewelry or denture cleaner.
| xkcd-sucks wrote:
| 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
| kazinator wrote:
| I have two sonicators, aged 3.5 and 5.5. The older one is going
| into grade 1 in September.
| bethekind wrote:
| This had me cackle :D
| showerst wrote:
| 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.
| htrp wrote:
| I think the idea is that the vibration transmits through the
| entire filter. The question is whether it's geometry/frequency
| specific
| sharpshadow wrote:
| It's likly not specific one could reduce the cold brewing
| time by shaking the jar.
| floatrock wrote:
| The embedded youtube video at 0:58 shows a laptop screen with
| some pretty fancy-looking simulation jiggles and heatmaps on
| what looks like an espresso filter.
|
| It also looks like a PDF of a paper, so presumably they have
| a paper that talks about the geometry/frequency interactions.
| eichin wrote:
| The article includes a link to the paper, which has
| simulation models of the acoustics, showing pressure levels
| and areas where cavitation can occur. (I didn't see
| anything about heating from dissipating the acoustic
| energy, though?)
| naltroc wrote:
| Two of my favorite things, cold brew and acoustics :D
| peteforde wrote:
| 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
| morning.
|
| Takeaway point: maybe Google your idea to see if other people
| have also had it before describing it as new.
| triceratops wrote:
| > 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.
| iancmceachern wrote:
| 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.
| daniel_reetz wrote:
| Also it will be punishing for pets and MEMs microphones.
| triceratops wrote:
| It's a prototype.
| fallat wrote:
| What? I went on Aliexpress and found a 40KHz transducer for
| $40. You can 3D print the attachment, can't you?
| iancmceachern wrote:
| A woofer from AliExpress is not a speaker with amp you
| can use for University level audio work.
|
| 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.
| fallat wrote:
| I looked up "transducer" and it seems to be what you'd
| need. But! You seem to have found where I was wrong: the
| horn. The horn seems to be the actual expensive part
| here. They could start a business I guess selling these
| en-masse. If anyone has any ideas how a maker could
| create this within reason please reply.
| iancmceachern wrote:
| You can't really sell them in big quantities because
| they're typically custom to the task. They need to be
| custom shaped for each application.
| srmatto wrote:
| Portafilters are made in mass so you could make horns for
| common portafilters.
| parineum wrote:
| > A woofer from AliExpress is not a speaker with amp you
| can use for University level audio work.
|
| We're talking about coffee here...
| iancmceachern wrote:
| Exactly!
|
| Wars have been fought over coffee, people regularly spend
| thousands for coffee machines. There are entire companies
| that exist just to cater to this market.
|
| Me, I'm a tea guy.
| JoBrad wrote:
| A wholly different set of wars
| bongodongobob wrote:
| They make ultrasonic jewelry cleaners for $75 that should
| work just fine. You're referencing something that is
| intended to be used with hundreds of gallons of water.
| iancmceachern wrote:
| I'm just talking about the paper. If they had referenced
| what you mention I would have referenced that
| karaterobot wrote:
| > However, engineers from UNSW have now developed a new way
| to make cold brew coffee in under three minutes - just like a
| regular hot brew - without sacrificing on the taste
| experience.
|
| 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.
| Alex3917 wrote:
| I hope the creator does another run of the original Sora Pot, I
| would buy that in a heart beat.
| kjkjadksj wrote:
| $695 isn't even bad, have people seen what even an entry level
| espresso machine can cost?
| throwaway482945 wrote:
| Is their approach different from this one from 5 years ago?
| https://youtu.be/cO6-SL3bMZg?si=_pVdOLNdej2pjDnT
| dahart wrote:
| 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).
|
| 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.
| sharpshadow wrote:
| 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.
| dahart wrote:
| 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.
| sharpshadow wrote:
| Yes hot brew coffee has more acidity tan cold brew. I like
| hand filter coffee and I use water around 90 degree
| Celsius. The higher I go with to boiling water the more it
| washes out bitter and acidic components.
| vallode wrote:
| 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...
| dahart wrote:
| Very interesting, and I missed the 100W bit, thanks! Yeah
| that would be really hard to do by hand for 2 minutes. Maybe
| Guinness records needs to see who can shake their cold brew
| hardest/longest. So this begs further questions for me, like
| can I shake with 10W for 30 minutes, or 10 minutes, or...?
| Does the frequency matter? Can we use one of those chem lab
| agitator machines to cold brew?
| kurthr wrote:
| I find it interesting that 100W for ~120 seconds is
| ~0.3kcal which for a 100ml cup is ~3C. They are right at
| the limit of power to flow rate. Much faster flow and
| presumably the cavitation wouldn't "brew" enough, while
| much slower and it would warm up the coffee noticeably. I'm
| doubtful the frequency matters much if the cavitation is
| what is causing the mixing since those are just bubbles
| emerging and popping, but the efficiency of coupling from
| ultrasonic wand to liquid could change a lot.
|
| 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.
|
| https://instantpot.com/products/instant-cold-brewer
| petre wrote:
| Yes, it's the frequency and also the amplitude that makes
| it faster. One could use a lab agitator but it would still
| be too slow. I think if you pour the water into an
| ultrasonic cleaner along with the coffee and filter the mix
| you might get the same result.
| aaarrm wrote:
| I think the size of the vibrations is important here. The
| paper mentions acoustic cavitation, which I believe would
| only really occur at small frequencies like the ones stated
| in the paper, not large shakes that you or I would do.
| lamename wrote:
| Thank you for saying this. When cold brew first came out, it
| was promoted as a brewing process that resulted in smoother
| (I'm guessing lower acidity) tasting coffee. Heating it up
| seemed natural, and its use in iced coffee seemed simply
| opportunistic. (In my experience at least).
|
| 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.
| dahart wrote:
| > brew temp and serving temp are orthogonal
|
| 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.
| kurthr wrote:
| It's funny cuz Charbux has no problem pouring hot espresso
| into cold ice milk with caramel and cream on top. I think
| it's pretty clearly just "baristas" justifying not changing
| their process, which is fine if a bit lazy and
| argumentative. Many coffee people are totally interested in
| finding new ways to do stuff, but they have to have the
| mental space to do it.
| LargoLasskhyfv wrote:
| Funny. Exactly that stuff is the only reason I've ever
| entered a Starbucks.
|
| 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.
| hinkley wrote:
| Pouring hot coffee onto plastic...
| look_lookatme wrote:
| Starbucks cold brew is actually not bad as far as cold
| brews go. It's definitely not iced coffee.
| NoGravitas wrote:
| > 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.
|
| 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.
| panopticon wrote:
| This is mainly what got me into roasting my own coffee.
| It was becoming a pain to find high quality dark roasts
| as all of the boutique roasters turned their efforts to
| light roasts.
| thrixton wrote:
| How did you go about roasting your own if you don't mind
| me asking.
| sq_ wrote:
| I hadn't thought of that as part of why finding good dark
| roasts has been hard for me. I've been annoyed at light
| roasts for a long time because I tend to find them acidic
| to the point that they're not enjoyable. I appreciate the
| bitterness and toastiness of a good dark roast, but
| finding good ones has been few and far between in my
| experience.
| an_aparallel wrote:
| i live in Sydney - not far from UNSW :P Campos coffee are
| phenomenal roaster imo. There's no hype around these
| light roasts - i would never cold brew them though - i've
| tried - and it's an incredibly inefficient form of
| brewing. But light roast itself is a phenomenal thing :)
| WirelessGigabit wrote:
| > 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.
|
| 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.
| lb1lf wrote:
| > It's like in the USA saying "I don't know, but let me
| get someone who does" isn't allowed.
|
| -Anecdotally, I believe this sentiment is inversely
| related to worker protections - it appears that the
| easier it is to fire you, the less likely you are to
| volunteer that you are not at the top of your game at all
| times.
| dmix wrote:
| You're saying Europeans are less smug than Americans?
| Spivak wrote:
| It's less about smugness and more that customer-service
| people are expected to behave like AI and always have an
| answer whether it's correct or not. I hope at some point
| we can drop the facade and "I don't know man, I just run
| the till. Do you want coffee or not?" becomes an
| acceptable response.
| macNchz wrote:
| In my experience having worked in coffee shops, restaurants
| and bars, there is a considerable overlap between the
| people asking for something off-menu that nobody has ever
| asked for, and the people who will never be satisfied with
| their order.
|
| 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.
| ada1981 wrote:
| The more complex, expensive and counter intuitive your
| morning coffee, the better!
|
| 90% of the experience is looking cool!
| ok123456 wrote:
| You can buy cold brew coffee at Costco in bulk in cans.
| Just throw some in the fridge.
| klyrs wrote:
| I was excited by this in theory, but it's some of the
| worst cold brew I've had. For shame, Costco is usually
| pretty good for selecting quality. Then again, my
| favorite preparation of cold brew is a shot of
| concentrate straight from the toddy.
| look_lookatme wrote:
| I agree. Bought a flat of it a couple of months ago and
| haven't drank more than half of them.
| Y_Y wrote:
| Pretension is nine tenths of the law
| lytfyre wrote:
| Look, my coffee routine is _perfectly reasonable_.
|
| 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.
| cratermoon wrote:
| As far as I can recall, I've always considered "cold" to
| apply to the brewing, not the drinking. I learned the
| technique as "brew extra strong, then add hot water to
| taste", and that's how I've been doing it since I bought my
| first cold-brew maker.
|
| 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.
| taude wrote:
| me, too. the Toddy brewer 30 years ago, even spoke of this.
| It was a way to premake your coffee concentrate, and then
| mix with water and microwave to heat up....
| lamename wrote:
| This was the first cold-brewing device I ever
| encountered....as a guest at someone else's house. Didn't
| know it had a name. Thanks!
| cratermoon wrote:
| That's exactly the one I started with, and used for years
| until the plastic got brittle and cracked.
| SamBam wrote:
| Barismo in Cambridge does (or did) a "hot draft" coffee, that
| is always on tap, is delicious, and is remarkably like hot
| cold brew. Their method is apparently a secret (although I'm
| sure more digging could find it), but I wouldn't be surprised
| if it wasn't basically on-demand heated cold brew. [1]
|
| 1. https://www.baristamagazine.com/the-function-and-future-
| of-b...
| Morizero wrote:
| Thanks for the tip, I'll hit them up tomorrow!
| Terr_ wrote:
| > But brew temp and serving temp are orthogonal.
|
| And if anyone doesn't believe this, challenge them to find a
| _truly_ "iced" coffee. :p
| opwieurposiu wrote:
| At my friends coffee shop they make cold brew with an elaborate
| laboratory glassware setup that drips ice-water through a
| filter. Looks pretty neat and sciencey. They got 4 of these
| devices running all the time in the back room. I was telling
| him all the other shops in town just fake it, he should put one
| of the devices out front so people can see his cold-brew is for
| real.
| dahart wrote:
| That is awesome! I would absolutely love it if more cafes did
| this. Let us know where it is so we can go patronize.
| giancarlostoro wrote:
| I would literally go to a shop doing this, like as often as
| possible. As a coffee lover, this is peak coffee shop.
|
| 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.
| samcheng wrote:
| I think this is called "Kyoto-style slow drip" coffee. I
| agree with you that the contraption should be in plain view
| of the customers!
|
| 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.
| Spivak wrote:
| It seems to be a niche taste among my friends, yes it's
| sour and bitter that's why I like it!
| bobthepanda wrote:
| To be fair all you need to actually make cold brew is a
| pitcher and a cheesecloth or some other filter. The absence
| of an apparatus does not make it fake.
| bananskalhalk wrote:
| Chilling warm brewed coffee is definitely faking it. And I
| presume all places selling "cold brew" is faking it so this
| guy is losing money by not showing off doing real cold brew
| with his apparatus.
| bobthepanda wrote:
| I'm not talking about chilling warm brewed coffee. All
| you need to make cold brew coffee is soak coffee grounds
| in cold water. Whether that is in a mason jar or through
| a thousand dollar complex laboratory setup is entirely an
| aesthetic choice.
|
| https://www.loveandlemons.com/cold-brew-coffee/
| klyrs wrote:
| My favorite route to camp coffee is running this GSI
| filter backwards:
|
| https://gsioutdoors.com/products/h2jo-filter
|
| Put a week's worth of grounds in the bottle, screw on the
| filter, pour in some cold water, steep for 24h, and
| transfer to another bottle. If somebody wants "drip"
| strength they can cut it with water, hot or cold.
| janalsncm wrote:
| It's a market for lemons at this point. Unless you can
| see an expensive apparatus or observe them soaking the
| coffee, there's no way to know if it's correct, and as a
| customer it means it's risky to buy if you care about the
| difference between refrigerated hot coffee and cold brew.
| deadlydose wrote:
| Risky to buy? It's not real estate it's a cup of coffee.
| And if you're worried about people faking it, just buy a
| $2 mason jar and make some in the fridge while you sleep.
|
| I don't get the fascination with paying exorbitant prices
| and constantly complaining when it's next to zero effort
| to make it at home, cold or hot. And the best part is you
| get to choose where your beans come from, you don't have
| to worry about the political slant du jour of the coffee
| shop, and you can do it all for a fraction of the price
| even when using the most expensive beans.
| janalsncm wrote:
| Yes, risky to buy. In the same way a slot machine has an
| expected value of 80-99% payout it's still a bad use of
| money even if you only put in $5.
|
| If you object to the word "risky" I used it in the sense
| of "uncertain you will get the value you expected".
| Perhaps there's a better word.
| metabagel wrote:
| > you don't have to worry about the political slant du
| jour of the coffee shop
|
| I can't say this has ever been an issue for me.
| Generally, they just want to sell me some coffee.
| rhaps0dy wrote:
| > It's a market for lemons at this point. Unless you can
| see an expensive apparatus or observe them soaking the
| coffee, there's no way to know if it's correct
|
| Presumably the taste should tell you whether it's
| correct. Otherwise why care if they fake it?
| klyrs wrote:
| I prefer to know what I'm buying before paying for it.
| majormajor wrote:
| Unless I'm a visiting tourist I'm likely to go back to a
| good coffee shop many times. Being surprised my cold brew
| isn't cold brew - both the caffeine content and taste are
| tells IMO - for one visit isn't life or death here. I
| just don't get it again.
| kjkjadksj wrote:
| The way I've seen it done is with one of those massive
| plastic commercial kitchen lidded containers, and a
| softball sized teabag of coffee sold by the restaurant
| supply company specifically for cold brewing like this.
| Then they put it in the walk in for a while to steep and
| sell it after a certain number of hours.
| this_steve_j wrote:
| Perhaps the Yama cold brew tower CDM25 is the device you saw.
| It is used at many fine establishments including my kitchen,
| and I also have the smaller CDM8. The numbers 8 and 25
| correspond to the number of cups of diluted 1:1 cold brew
| that it produces in a single cycle (6-12 hours).
|
| https://yama-glass.com/collections/cold-brew-towers
| tedmiston wrote:
| > At my friends coffee shop they make cold brew with an
| elaborate laboratory glassware setup that drips ice-water
| through a filter. Looks pretty neat and sciencey.
|
| Likely the Yama cold brew tower [1].
|
| [1]: https://prima-coffee.com/equipment/yama/yamcdm25sbk-
| yama-pp
| cout wrote:
| As I understand, the serving temperature of coffee does have an
| effect on perceived acidity (which is NOT the same as pH),
| though I don't understand the science behind it. Here is one
| paper that claims it is due to release of volatiles at higher
| temperatures:
| https://www.sciencedirect.com/science/article/abs/pii/S03088...
|
| 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.
| dahart wrote:
| I could buy it, that it might have some perceived effect
| that's measurable. I have tasted many a warmed up cold brew,
| and it tastes like coffee to me. The ones that are actually
| cold brewed are milder, and the hot brewed fakes are
| noticeably sharper, and I feel it later in my throat... The
| thing for me is that the actual acidity of coffee has started
| causing some inflammation. The reason I'm seeking cold brew
| is my doctor recommended it. I'm less worried about the
| perception of acidity and more worried about issues caused by
| too low pH.
| nkozyra wrote:
| Ah, just posted that I detect a change in flavor after I heat
| cold brew (but didn't know a mechanism behind it)!
| YetAnotherNick wrote:
| Also, in my experience heating the coffee in microwave
| increase perceived acidity even more. Which kind of make
| sense with this explaination as there could be pockets of
| superheated water when it is microwaved.
| eternauta3k wrote:
| Could you try giving it a good stir right before putting it
| in the microwave?
| klausa wrote:
| Isn't that a pretty generic and well known (and not coffee-
| specific) effect, that flavor is pretty temperature
| dependent?
|
| Warm Coke is disgusting; freezing cold Diet Coke is the
| nectar of gods.
| parpfish wrote:
| room temp soda is my favorite. there's so much more flavor
| when it's not cold.
|
| however HOT cola (which can happen if you leave it in a
| car) is physically painful because something weird happens
| to the bubbles
| hinkley wrote:
| Cold brew isn't about pH, it's about bitters. The oils aren't
| (just) acidic, they're bitter, and that's what you don't get
| when you make real cold brew instead of failing it.
|
| Acetic acid is sour. Alkaloids are bitter.
| rrrrrrrrrrrryan wrote:
| As a complete layman, when I tried tossing cold brew into the
| microwave it ended up tasting pretty gross. Like, jarringly
| so.
|
| 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.
| ch4s3 wrote:
| Yeah, there are still a lot of dissolved coffee solids in
| cold brew that get further extracted if heated. There are
| also a lot of volatile compounds that break down when
| heated. The idea that you can just reheat coffee, even cold
| brew and have it taste the same is just ridiculous.
| draw_down wrote:
| I agree people can be really annoying about heating up cold
| brew. Iced espresso no problem, heated cold brew = mind blown.
| csmpltn wrote:
| This is an extreme form of coffee hipsterism. "Cold brew, but
| steamed please". Brother, this is starting to get ridiculous.
| nkrisc wrote:
| It's no different than drinking an iced coffee drink that was
| made from coffee brewed traditionally.
| dahart wrote:
| That'd be true if putting ice in coffee reduced its
| acidity. Heating cold brew brings a lower acidity liquid up
| to a nice warm good morning temperature.
| dahart wrote:
| My doctor recommended cold brew for lower acidity, because
| hot brew is bothering me. Cold brew is just a brewing process
| and has nothing to do with serving temperature. Cold brew has
| never meant served cold. So what, exactly, is ridiculous
| about warming up cold brewed coffee? I like my coffee hot,
| like a lot of people, and I'd like it if I can keep drinking
| coffee and don't have to stop due to the acidity.
| ackfoobar wrote:
| It might be obvious but I have to ask, is that a stomach
| problem?
| dahart wrote:
| Not for me, but it is for some people. My current issue
| is more esophageal, my throat gets inflamed with too much
| acid then it feels like I have food stuck and can't
| swallow it. Other people have stomach issues, ulcers,
| etc. but still want to enjoy coffee, so I think there's
| plenty of reasons for cold brew served hot to exist.
| aaarrm wrote:
| Not the person you are asking, but I do have GI issues
| due to the acidity with coffee. It can cause reflux,
| ulcers, and more for people if they are sensitive to the
| added acidity.
| sushid wrote:
| I'm a coffee snob and I can respect your preferences but
| have you considered non-coffee alternatives? Japanese and
| Chinese tea culture can be fun to delve into and tea would
| probably be easier on your stomach.
| dahart wrote:
| I definitely have considered alternatives, and do drink
| tea, more now than before, in part because of my negative
| experience experiences trying to get hot coffee that was
| cold brewed. Finding the fake cold brew many places
| really scares me off cold brew more than baristas who
| don't want to heat the coffee. Single shot americano is
| another alternative with a bit lower acidity, I believe,
| and even with that I often get mild push-back from
| baristas... "you sure?? We pull two shots anyway..."
|
| 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.
| windexh8er wrote:
| For people who are accustomed to cold brew (we always have
| cold brew in the fridge and grounds steeping) there's a very
| large difference in flavor and profile using the same beans.
| This also translates when it's heated, although I will say I
| don't do that often because I enjoy it cold more than hot.
|
| 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.
| surement wrote:
| > extreme form of coffee hipsterism
|
| 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.
| the_optimist wrote:
| "Old Brew" can be more valuable. You must check the vintage and
| terrioir.
| nkozyra wrote:
| I find that heating cold brew reintroduces some of the flavor
| of hot brewed coffee, though I've never been able to pinpoint a
| mechanism for it.
| bunderbunder wrote:
| Speculation: A lot of it is that chemicals that contribute to
| flavor are more volatile at higher temperatures.
|
| 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.
| dev-tacular wrote:
| Does cold brew served hot taste good? I have never really
| considered asking for it hot before simply because I thought it
| would just be like regular coffee. But, I guess if regular
| coffee tastes different cold and hot, cold brew should too.
| rpdillon wrote:
| Cold brew is much less acidic, and I find warmed cold brew to
| be exceptionally smooth compared with hot brew. I got my
| recipe from a NYT interview with the CEO (I think?) of Blue
| Bottle, though I've since lost the link. This is my copy:
|
| https://rpdillon.net/recipes/new-orleans-cold-brew-
| coffee.ht...
| bunderbunder wrote:
| Yes. The major reason for cold brewing coffee (or tea!) over
| simply cooling and icing hot brew is that you extract a
| different mix of compounds from the bean (or leaf) due to
| different chemicals having different levels of solubility at
| different temperatures.
|
| Serving temperature affects flavor, too, of course. Darn near
| everything does.
|
| See, for example: https://www.mdpi.com/2304-8158/9/7/902
| marcoalopez wrote:
| This is only partly true. Because low-temperature
| extraction is much less efficient, it requires a much
| longer immersion/exposure time than hot extraction at
| ambient or slightly higher pressure. One of the effects of
| this type of cold extraction is the oxidation of the
| coffee, which is much greater with this method, giving the
| coffee an oxidised taste which, although not bad in itself
| (nothing is set in stone about personal taste), is not to
| everyone's liking. For my taste, I prefer to make it hot
| (with a higher coffee/water ratio than usual) and cool it
| down by diluting it with water or ice.
| bunderbunder wrote:
| Definitely. Though the oxidation seems different? I don't
| find cold brew to taste "stale" the way hot brewed coffee
| that's been stored overnight in the refrigerator does.
|
| 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.
| eternauta3k wrote:
| Won't the CO2 make the water acidic?
| dahart wrote:
| Tastes good to me. It is like regular coffee, just lower
| acidity, which is what I need. I want it to taste the same as
| regular coffee! ;) To be fair, it usually tastes milder than
| how brewed coffee, and this is one of the things people like
| about cold brew.
| HankB99 wrote:
| Good is subjective. I've trialed cold brew at home and have
| been serving it warmed. I prefer my coffee hot. I thought it
| tasted fine, different but neither better nor worse than hot
| brew (drip in my case.)
|
| 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.
| jmilloy wrote:
| Everything you say makes sense, with the exception of your
| expectation not to pay extra for an unusual order (for that
| cafe). Consider if I asked for my salad to be roasted, and
| balked at a surcharge on the grounds that they also have
| roasted brussel sprouts! I don't think it's up to you to decide
| what orders fit into their flow and which cost extra. I'm glad
| you found the places that will make the coffee the you like.
| dahart wrote:
| It's not an unusual order, hot coffee is sold millions of
| times per day, and steaming comes with many coffee drinks,
| it's par for the course with espresso drinks. Roasting a
| salad is weird, hot coffee is not, so your example is straw
| man. The "cold" in cold brew is not referring to serving
| temperature, that's your own misunderstanding, so I find the
| suggestion that hot cold brew is weird to be pretty funny. As
| has been said many times in this thread, nobody balks at the
| idea of cold hot brew, nor do they charge extra.
| shawabawa3 wrote:
| But hot cold brew is weird, as you've just been complaining
| about people not doing it or finding it weird
|
| If hot cold brew was common you wouldn't pay extra for it
| dahart wrote:
| The biggest sticking point is not the heating of the
| coffee at all, it's the widespread misunderstanding of
| the what the word cold means in the term "cold brew". It
| is incorrectly assumed that brewed relatively cold (room
| temperature) means served ice cold. Somehow a lot of
| people can't understand the verb brew has nothing to do
| with serving temperature. Does that make sense to you?
| artimaeis wrote:
| Former barista, it _is_ an unusual order from the
| perspective behind the bar. Unusual in that I never have
| heard of someone ordering a warmed cold brew.
|
| 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.
| dahart wrote:
| I appreciate that, it does help, thank you. Indeed I
| found a few cafes that were used to it, and quite a few
| that weren't. I think you're totally right that this
| trips up some people's flow especially when they're not
| used to it. I'm okay with accepting it actually is
| unusual for some and just instead being the person
| complaining that it _should_ be usual or expected even if
| it isn't always. FWIW I have tried it microwaved, and
| it's fine, but never in a cafe - baristas have always
| steamed it until warm or hot. That also works for me.
| bethekind wrote:
| Using low frequency sound will agitate the solute and solvent,
| speeding up the natural cold brew process.
|
| 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
| petre wrote:
| That reminds me of the _Soul Kitchen_ movie when a client of a
| fancy restaurant asked for a hot gazpacio. The waiter escalated
| to the chef who calmly explained to the client what a gazpacio
| is. After the client insisted, shouting at him, the chef
| refused driving his knife into the client 's table.
|
| https://youtu.be/rQ61MfRBSQg
| SamBam wrote:
| > We had gazpacho soup for starters... I didn't know that
| gazpacho soup was meant to be served cold. I called over the
| chef and told him to take it away and bring it back hot! So
| he did... the looks on their faces still haunt me today! I
| thought they were laughing at the chef, when all the time
| they were laughing at me as I ate my piping hot gazpacho
| soup! I never ate at the Captain's table again. That was the
| end of my career. - Rimmer, _Red Dwarf_
|
| https://www.youtube.com/watch?v=3ZGJHDegPcU
| aspenmayer wrote:
| Red Dwarf is one of the most unhinged shows I've seen, in
| the best way. Nice reference, as I was also thinking of hot
| gazpacho soup, but had forgotten this scene until you
| reminded me of it.
| D13Fd wrote:
| I drink only cold brew normally, and I've noticed this as well.
| It's 50/50 whether you will get actually cold brew at any given
| coffee shop or just iced hot-brew coffee, which tastes
| different and has much less caffeine.
|
| Cold brew needs a new name or it will likely fade away over
| time.
| fuzzzerd wrote:
| There's nothing wrong with the name cold brew. It describes
| the difference from "standard" coffee. It is the charlatans
| selling warm brew over ice that devalue it.
|
| 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.
| dahart wrote:
| There _shouldn't_ be a problem with the name, but my
| experience tells me that people don't comprehend it the
| majority of the time, and assume incorrectly that cold
| brewed must be served cold. This mentality is even here in
| this thread in a few places. It does seem like some other
| word than "cold" might help avoid leading people into an
| erroneous conclusion.
| m463 wrote:
| I've been doing cold brew for a while now.
|
| 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.
| elevatedastalt wrote:
| The emperor really has no clothes when it comes to food fads.
|
| 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]
| fwip wrote:
| Speculation:
|
| 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.
| elevatedastalt wrote:
| That's a good point. From what I understand, cold brew can
| be made at room temperature too. So it will need storage
| but not cold storage. But it's possible I don't have the
| full picture.
| Bluecobra wrote:
| I have found no difference in just using cold water and
| having it sit on my counter overnight vs. keeping in the
| fridge. It is nice to still refrigerate it to use less
| ice or no ice though. In a retail setting, I would think
| customers would demand a cold product (I would). The
| Starbucks near me serves Nitro Cold Brew and for some
| reason it's always warm/room temp, and they purposely do
| not put any ice in it. Other locations seem to not have
| this issue so maybe it's broken equipment or training.
| stephenhuey wrote:
| Cold brew coffee is by definition not brewed with hot
| water the way most coffee is (in other words, room
| temperature is within the range of "cold" when talking
| about brewing with "cold" water). So, it's not necessary
| for it to be served cold to enjoy the benefits of the
| cold brew method--sometimes I like it chilled, but I also
| enjoy the taste at room temperature or warmer.
| elevatedastalt wrote:
| Cold brew is so much more caffeinated that I've seen most
| shops add tons of ice to create enough drinkable volume
| without giving you enough caffeine to knock a horse down.
| tracker1 wrote:
| As to C, that applies to cold brew just as well as hot brewed
| coffee.
| elevatedastalt wrote:
| Possibly, but I've seen cold brew served mostly just by
| itself or just some syrup / cream, as opposed to
| cappuccinos / lattes which need much more milk.
| askvictor wrote:
| Cafes often charge more for niche items, mainly because they
| can. There's also the workflow of the barista to consider -
| leaving the espresso machine to get ice from the freezer
| disrupts the flow of constantly pumping out lattes.
| 0xbadcafebee wrote:
| Flavor compound release is affected by method, temperature, and
| wat. The method (which _includes_ temperature, but is not
| restricted to it) extracts certain compounds. The release is
| affected by temperature and the amount and type of compounds in
| solution. It 's entirely possible that warming up a cold-brewed
| coffee could create off-flavors.
|
| 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)
| tracker1 wrote:
| I like, and use the term "iced cold brew" for serving cold...
| not sure about serving cold without ice... In that my first
| introduction to it, the person would be taking it from a
| container in the fridge, adding some water and microwaving it
| to heat it up.
|
| 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.
| mmanfrin wrote:
| > I was laughed at in one hipster joint for asking for a
| steamed or warmed cold-brew
|
| 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
| dahart wrote:
| Why's that? What's ironic? Do you feel like that's a fair
| gotcha? Do you know why I asked for a heated 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.
| romafirst3 wrote:
| All coffees tend to be in the same ph range regardless of
| brewing technique.
| kjkjadksj wrote:
| I wonder if you can deal with the acidity issue in a quick and
| dirty manner by just throwing in some baking soda into your
| grinds and brewing hot?
| blincoln wrote:
| 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.
|
| 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.
| eschneider wrote:
| 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.
| eezurr wrote:
| 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
|
| It actually tastes pretty good. Most of the acrid taste from
| (hot) instant isnt there
| triceratops wrote:
| But then you miss out on the self-flagellation aspect of
| drinking instant.
| all2 wrote:
| You can no longer mutter to your coworkers _I just need the
| caffeine_ as you add the 5th scoop of instant to your
| Styrofoam cup of hot water.
| MisterBastahrd wrote:
| Anyone ever tried dumping coffee grinds and water into an
| ultrasonic jewelry cleaner?
| bethekind wrote:
| Wattage might not be high enough to notice a difference, but
| might be fun
| MisterBastahrd wrote:
| So I looked at Amazon for products. There's an ultrasonic
| brewer that is used for both cold brew coffee and also for
| rapid infusion of spirits with charred barrel staves. There's
| also a stir plate / french press combo for sale that
| apparently does fine cold brew in 20 minutes.
| monkayMan wrote:
| 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!
| pain_perdu wrote:
| The longtime CEO/President of Starbucks recently invested in a
| Cold Brew startup called Cumulus which makes instead coldbrew via
| a $600 countertop machine.
|
| https://dailycoffeenews.com/2023/11/16/howard-schultz-part-o...
| jerlam wrote:
| _The machine uses single-serve, single-use aluminum pods, which
| along with the machines are expected to be available next
| summer._
|
| Of course, it's an attempt to be the next Keurig/Nespresso.
| hardwaregeek wrote:
| 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
| gruez wrote:
| Wouldn't it be cheaper to brew the coffee in a sealed/vacuum
| chamber instead? Whatever machine they're using to generate
| "acoustic cavitation" doesn't sound cheap.
| quarkw wrote:
| That was my first thought. It seems like others have already
| tried it with good results.
|
| 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.
| antonchekhov wrote:
| 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.
| beefman wrote:
| 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
|
| [1] https://www.engadget.com/osma-pro-cold-brew-coffee-
| machine-r...
| surfingdino wrote:
| James Hoffman's video on the subject incoming in 3... 2... 1...
| can't wait :-)
| knicholes wrote:
| Does anyone know what make this better than just stirring for
| three minutes?
| eichin wrote:
| The paper lists many things they tested for, but the
| fascinating one is that the coffee oils and water get
| _emulsified_ which isn 't going to happen with any level of
| stirring below "puree" :-)
| thsksbd wrote:
| I'm guessing few on this board have heard an uktrasonicator in
| action.
|
| 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
| askvictor wrote:
| > heard an uktrasonicator
|
| Is this a joke?
| bastardoperator wrote:
| Whatever they're holding up in that picture, it looks more like
| iced tea versus cold brew coffee.
| maherbeg wrote:
| Huh, I'd love to taste a sample. This would be such a nice
| extension to an existing Espresso setup!
| dukeofdoom wrote:
| They should add led lights and ultrasonic vibration to the cup
| for a futuristic cyber punk style presentation.
| lacrosse_tannin wrote:
| In the picture, it looks like they're posing with some refreshing
| sun-tea. Maybe they should try 4 minutes.
| ugh123 wrote:
| Here's my iced coffee prep for those who like it strong with a
| bite:
|
| 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.
| greentxt wrote:
| Guess this proves Havana Syndrome is real after all.
| LargoLasskhyfv wrote:
| https://en.wikipedia.org/wiki/Sonication
|
| How will cats feel about that high-pitched noise?
| cwillu wrote:
| 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*!
| m463 wrote:
| > _sonicated_
|
| I sense a new term making its way into coffee marketeering...
| selimnairb wrote:
| First they should teach Australian baristas what iced coffee is.
| eichin wrote:
| Ooh an excuse to upgrade some homelab equipment :-)
|
| (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.)
| 0xbadcafebee wrote:
| 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
| eternauta3k wrote:
| If the cavitation really is important then no, it won't have
| the same effect. But maybe the cavitation is not important! Try
| it out and report back.
| kjkjadksj wrote:
| Buy an ultrasonic cleaner off the shelf and just decant the
| grounds out of the coffee when you are done
| nefrix wrote:
| Finally, the scientists discovered a life changing thing.
| spython wrote:
| Or you could use a (quite affordable) ultrasonic machine designed
| for gentle cleaning of jewelry, dentures, glasses..
|
| 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.
|
| [0] https://rybakov.com/blog/smelling_cz/
| cabirum wrote:
| 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.
| acc_297 wrote:
| unfortunate that the acoustic cavitation frequency is just barely
| within the range some dogs can still perceive
| Spaced-Oddity wrote:
| 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.
|
| The inventor of the aeropress shared this tip. Here's his recipe:
|
| https://www.youtube.com/watch?v=oUD6HxDnlwI&t=56s&ab_channel...
| mianos wrote:
| "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 .."
|
| 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.
| shirro wrote:
| Wake up yourself and all the dogs in the neighborhood at the same
| time. I want one.
|
| 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.
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