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Cold brew coffee in 3 minutes using acoustic cavitation

unsw.edu.au

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Re: Cold brew coffee in 3 minutes using acoustic cavitation

#351

Post by pkroll »

lostlogin wrote: post #285
kimixa wrote: post #270

Earlier quoted context omitted.

I also like the "ritual" of brewing a coffee to help me wake up in the morning. And even then, it's less than 10 minutes total preparing a pour over, it probably takes less time than cleaning out a filter machine would. 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 gri…

> 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 he…

Oh, THAT's pretty? I give you the Manument: https://manument.com/en/manument-leva-machine

Well. Not GIVE. It's $20K.

Re: Cold brew coffee in 3 minutes using acoustic cavitation

#352

Post by pkroll »

solardev wrote: post #251
ChrisMarshallNY wrote: post #247

Earlier quoted context omitted.

Yeah. My friend has one that cost around 3 grand. 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.

It's got a decent self-cleaning cycle. Every month or two, it'll ask you to put in a cleaning tablet (about $2 for the OEM version, or there are cheaper generic ones). It goes through an internal cleanse and poops out a slop of muckety muck. I put on soft yoga music for mine, but that's optional. Ten minutes later it's ready to use again. About half as frequently, it'll also ask you to put in a descaling tablet. Simi…

For anyone who hasn't gotten into the coffee insanity yet, he doesn't mean his friend literally gives the coffee acupuncture... but a cork with some acupuncture needles (or a device that looks like such) is commonly (!) used to stir/even out/redistribute/break up clumps of coffee in the portafilter before tamping. And reading that I now need to go get some coffee.

Re: Cold brew coffee in 3 minutes using acoustic cavitation

#353

Post by currency »

insane_dreamer wrote: post #332
currency wrote: post #311

Earlier quoted context omitted.

Making espresso with my semi-auto Breville Infuser is almost exactly as much fuss as a 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.

You still weigh the grounds? The difference with eyeballing it is probably too negligible to be noticed.

I'm not very good at eyeballing it, so it helps me stay consistent.

Re: Cold brew coffee in 3 minutes using acoustic cavitation

#354

Post by CydeWeys »

beAbU wrote: post #350
CydeWeys wrote: post #300

Earlier quoted context omitted.

Yeah, good point on the constant power draw too. I forgot to mention the last bit of kit I use to make my simple at-home coffees: an electric kettle. (And speaking of which, if I ever build my own home, I'm putting 240V counter-top outlets in the kitchen.)

Yeah thats a strange US only quirk: lack of kettles and 120V power. I have a 3Kw kettle at home. I boils 2l of water in a few minutes. If I add just enough for one hot drink, then it finishes before I have my mug and ingredients ready. I cannot imagine a home without a kettle, its the first appliance I bought when I moved countries. I also cannot abide by a kettle less than 3Kw anymore either.

It's annoying because we have dedicated 240V circuits for all major installed appliances in US households (drying machine, electric stove, HVAC), as well as, increasingly, 240V circuits in the garage for EV charging.

But no one is putting in 240V circuits for countertop plug-in appliances afaik, even though there's absolutely no reason you can't do so.

And by the way, electric kettle are quite common in the US amongst the tea or fancy coffee drinking set.

Re: Cold brew coffee in 3 minutes using acoustic cavitation

#355

Post by cafebee »

kibibyte wrote: post #347
cafebee wrote: post #274

Earlier quoted context omitted.

What are the variables that a roaster can tweak? Temperature, time, and lots of others I assume? Which variable can produce vegetal flavors? I’d never thought much about roasting but now I’m curious!

This is something that I still consider to be black magic to me, so this is my best attempt at describing a number of the variables. Temperature is controlled in two ways: direct heat input (e.g. gas flame heating the outside of the rotating drum) and air flow (moving air through the roasting drum to the exhaust). It's not 1 measurement though: there is bean temperature (measured by a probe stuck into the pile of bea…

Thank you for the detailed answer! It makes sense that the vegetal flavors are the raw flavors from the beans themselves. And that temperature is much more complicated than it appears. I also appreciate the Scott Rao pointer, perhaps that will be interesting future reading.

Re: Cold brew coffee in 3 minutes using acoustic cavitation

#356

Post by dahart »

romafirst3 wrote: post #346
dahart wrote: post #334

Earlier quoted context omitted.

This contradicts the common claims about cold brew. Do you have any references on it? When I google it now, the first answer I get says hot brewed gives a pH around 4.8 and cold brewed around 5.1, which if true is a 2x difference in acids. My home tests with pH strips show drip and pour overs to be a bit more acidic than a very fast aeropress. There are low acidity beans, and as I just found out additives to countera…

Are you sure when you are brewing that the concentrations/extractions are the same ? If you brew an aeropress and then dilute it, it will probably be less acidic. Here is more info on hot/cold https://www.researchgate.net/figure/pH-values-of-six-coffee-...

I’m not sure of anything TBH, mostly chatting about what I’ve heard from others. My doc told me cold brew is lower acidity, and googling I get the same answer, but yeah I have no idea about whether the extraction or concentration is a fair comparison. I’m interested in any rigorous measurements.

Re: Cold brew coffee in 3 minutes using acoustic cavitation

#357

Post by dahart »

boulos wrote: post #345
dahart wrote: post #262

Earlier quoted context omitted.

I can understand that. I do feel like the reaction I’m sometimes getting is reflexive and not given any thought. My daughter worked at Starbucks for a while, and told me about crappy customers doing this all the time - ordering drinks with questionable modifications and then sending them back when it wasn’t as good as they hoped. Her initial reaction to my steamed cold brew story was that I’m asking for something unu…

Maybe ask them to make you "an Americano, but with cold brew coffee"? Trick them into it being an on-the-menu item.

I like this idea. Today I just talked the nearest cafe into trying a steamed nitro cold brew. The owner said it was a slightly weird idea, but liked it and agreed to make it whenever I ask.

Re: Cold brew coffee in 3 minutes using acoustic cavitation

#358

Post by romafirst3 »

dahart wrote: post #356
romafirst3 wrote: post #346

Earlier quoted context omitted.

Are you sure when you are brewing that the concentrations/extractions are the same ? If you brew an aeropress and then dilute it, it will probably be less acidic. Here is more info on hot/cold https://www.researchgate.net/figure/pH-values-of-six-coffee-...

I’m not sure of anything TBH, mostly chatting about what I’ve heard from others. My doc told me cold brew is lower acidity, and googling I get the same answer, but yeah I have no idea about whether the extraction or concentration is a fair comparison. I’m interested in any rigorous measurements.

There are very few rigorous measurements and a lot of people just saying whatever they feel like :)

With regards to acid and GERD which is when doctors normally talk about coffee acidity, what they usually say makes no sense at all and they should know better.

The idea that a very weak acid like coffee would increase the acidity of your stomach which contains a very very strong acid (1.5 to 3.5) is ridiculous. I think what they should just say is that hot coffee can relax the muscles keeping your stomach contents in.

Re: Cold brew coffee in 3 minutes using acoustic cavitation

#359

Post by ada1981 »

lytfyre wrote: post #157
ada1981 wrote: post #58

Earlier quoted context omitted.

The more complex, expensive and counter intuitive your morning coffee, the better! 90% of the experience is looking cool!

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 i…

The entire hipster aesthetic is assuring people they don’t look cool in an attempt to look cool.

Re: Cold brew coffee in 3 minutes using acoustic cavitation

#360

Post by kjkjadksj »

bobthepanda wrote: post #276
dahart wrote: post #256

Earlier quoted context omitted.

Okay this is a totally wild and hilarious coincidence, but I came home tonight and told my wife about this thread. Turns out that, today of all days, without knowing I was ranting about cold brew on HN, she did a careful home experiment with her coffee using baking soda, so I can report on what she found. She has suffered me complaining about fake cold brew and rude baristas before, but it’s been months since we disc…

I suppose this makes sense? Baking soda’s main flavor profile is bitter, but coffee is already bitter so I suppose it isn’t going to make things worse. (Compare this to its use in baking, where you have to be careful not to use too much so the bitterness doesn’t ruin the baked good.)

You are extrapolating baking rules-of-thumb but forgetting the chemistry that is happening. When you add baking soda to something acidic, you end up with less baking soda, you can even end up with zero baking soda leftover with enough acid, as the baking soda reacts with the free hydrogen ion and yields water, co2, and a sodium ion.
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