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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

#101

Post by petre »

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…

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

Re: Cold brew coffee in 3 minutes using acoustic cavitation

#102

Post by aaarrm »

ackfoobar wrote: post #89
dahart wrote: post #76

Earlier quoted context omitted.

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.

It might be obvious but I have to ask, is that a stomach problem?

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.

Re: Cold brew coffee in 3 minutes using acoustic cavitation

#103

Post by [deleted] »

vincentrolfs wrote: post #90
hammock wrote: post #72

Earlier quoted context omitted.

>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

I agree with your confusion, are we all talking about the same thing?

[deleted]

Re: Cold brew coffee in 3 minutes using acoustic cavitation

#104

Post by marcoalopez »

bunderbunder wrote: post #78
dev-tacular wrote: post #70

Earlier quoted context omitted.

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.

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

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.

Re: Cold brew coffee in 3 minutes using acoustic cavitation

#105

Post by cratermoon »

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…

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.

Re: Cold brew coffee in 3 minutes using acoustic cavitation

#106

Post by klausa »

cout wrote: post #46
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…

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 re…

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.

Re: Cold brew coffee in 3 minutes using acoustic cavitation

#107

Post by parpfish »

klausa wrote: post #106
cout wrote: post #46

Earlier quoted context omitted.

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 re…

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.

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

Re: Cold brew coffee in 3 minutes using acoustic cavitation

#108

Post by shawabawa3 »

dahart wrote: post #93
jmilloy wrote: post #84

Earlier quoted context omitted.

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 lik…

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

Re: Cold brew coffee in 3 minutes using acoustic cavitation

#109

Post by D13Fd »

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…

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.

Re: Cold brew coffee in 3 minutes using acoustic cavitation

#110

Post by ugh123 »

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.

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