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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

#151

Post by dahart »

shawabawa3 wrote: post #108
dahart wrote: post #93

Earlier quoted context omitted.

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 be…

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

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?

Re: Cold brew coffee in 3 minutes using acoustic cavitation

#152

Post by lamename »

taude wrote: post #147
cratermoon wrote: post #105

Earlier quoted context omitted.

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.

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....

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!

Re: Cold brew coffee in 3 minutes using acoustic cavitation

#154

Post by Terr_ »

lamename wrote: post #32
dahart wrote: post #17

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 refus…

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 turne…

> But brew temp and serving temp are orthogonal.

And if anyone doesn't believe this, challenge them to find a truly "iced" coffee. :p

Re: Cold brew coffee in 3 minutes using acoustic cavitation

#155

Post by [deleted] »

kurthr wrote: post #66
dahart wrote: post #40

Earlier quoted context omitted.

> 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 w…

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.

[deleted]

Re: Cold brew coffee in 3 minutes using acoustic cavitation

#156

Post by dmix »

WirelessGigabit wrote: post #130
dahart wrote: post #40

Earlier quoted context omitted.

> 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 w…

> 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…

You're saying Europeans are less smug than Americans?

Re: Cold brew coffee in 3 minutes using acoustic cavitation

#157

Post by lytfyre »

ada1981 wrote: post #58
lamename wrote: post #32

Earlier quoted context omitted.

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 turne…

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 intuitive.

I can also assure you that I don't look cool while doing it.

Re: Cold brew coffee in 3 minutes using acoustic cavitation

#158

Post by 0xbadcafebee »

dahart wrote: post #17

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 refus…

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)

Re: Cold brew coffee in 3 minutes using acoustic cavitation

#159

Post by sharpshadow »

dahart wrote: post #26
sharpshadow wrote: post #22

Earlier quoted context omitted.

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.

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.

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.

Re: Cold brew coffee in 3 minutes using acoustic cavitation

#160

Post by macNchz »

dahart wrote: post #40
lamename wrote: post #32

Earlier quoted context omitted.

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 turne…

> 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 w…

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.

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