Iced coffee via rapid chill (vs Japanese iced method)

Coffee preparation techniques besides espresso like pourover.

#1: Post by dsc106 »

Japanese iced coffee is considered superior to cold brew by many for retaining acidity and flavor notes better due to a high heat extraction. But it is still limited due to having less hot water to extract with, and needing to modify grind size and ratio to work.

Brewing hot coffee and slowly cooling it in the fridge causes oxidation + loss of aromatics.

Enter rapid chilling. James Hoffman did a video on one device, The ColdWave years back:

There is also the HyperChiller and the Zoku.

The hyperchiller is faster to chill, but bulkier + plastic contact with lid.

The Zoku chills slower, but takes up less space in freezer. Unlike the other two devices, it contains "nasty freezing chemicals" in the interior... but I am not sure this matters for safety/exposure as it's contained within stainless steel walls? Any insight? I suspect it may actually be a benefit with lower maintained and less freezer space footprint.


Stands to reason a standard v60 brew with a rapid chill via one of these devices should produce the very best result for iced coffee - can anyone speak to this? Any experiences?

I'm trying to decide if it is worth getting a rapid chiller and if so, which one? These are the only 3 units I know of... currently leaning Zoku.

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#2: Post by SteveRhinehart »

Hyperchiller and Coldwave both use water to chill. The Hyperchiller is refillable, the Coldwave is not.

Crash chilling without dilution is by far my favorite way to cool coffee. I think it produces flavor closest to the hot brewed equivalent, though aromatics are dulled somewhat and the flavor balance will change with temperature.

I just use an ice bath and a stainless steel shaker tin, but I've used the Hyperchiller and did like it if I only needed to cool one drink. It and the Coldwave have the same limitation in that they only have so much ice mass to change phase and then need to be frozen again. It's that limitation that has stopped me from buying either one. I make and keep ice around regularly for cocktails, so if I wish to cool some coffee I have plenty on hand for an ice bath.

dsc106 (original poster)

#3: Post by dsc106 (original poster) »

Thanks Steve, cool to hear your experience coincides with this theorizing, makes sense!

What do you think of the Zoku with its internal gel? Any concerns? I only cool one single drink as the sole coffee drinker in the house, drinking just one cup a day.

Regarding your method, so essentially you use a stainless steel cocktail shaker tin inside something like a small cambro container filled with ice water? Pour coffee into tin, stir, pour back into a glass?

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#4: Post by SteveRhinehart »

dsc106 wrote:Regarding your method, so essentially you use a stainless steel cocktail shaker tin inside something like a small cambro container filled with ice water? Pour coffee into tin, stir, pour back into a glass?
That is exactly the method, in fact. A smaller brew of around 300 ml will chill in just about a minute with stirring.

For the Zoku, as I haven't used it I'm unable to say whether it would be a good alternative. Some of the reviews are fairly positive. It's my understanding that some gels like this are more or less thickened water, while others are some other chemicals that may have a stronger cooling effect in phase change. Without knowing what's inside I would say at worst case you have something that behaves almost exactly like water does, and looking at the thinness of the wall I'd be somewhat concerned that it may not entirely chill a full serving of fresh, hot coffee. But again, that's only speculating and some folks seem rather happy with it in their reviews.

dsc106 (original poster)

#5: Post by dsc106 (original poster) »

Ok I bought and tried the Zoku, 300ml brew took about 6 minute to hit room temp... a lot slower than your method.

On the chance I did something wrong (I only froze it for 10 hours, it says 8+), and when I removed I didn't put it in the plastic sleeve which perhaps keeps thermal mass in. But I'm curious how much quicker it will actually be. I brewed into an carafe first so the temp when I poured it in was only 155F. So not thrilled with how long it took to cool. Maybe brewing directly into it would be better.

How long does it take coffee to lose aromatics/oxidize? I'm wondering if the 10 minutes of sitting prior to being chilled are all that impactful or not.


#6: Post by Stavey »

Coldwave hands down. The hyperchiller feels cheaply made . I was not impressed to say the least. I returned it almost immediately. I drink a lot of iced coffee during warm months. That being said I want my iced coffee to taste as it does when it's hot. For this reason I tried the coldwave. For my application this is the clear winner . Holds a larger amount than the others, cools relatively fast, and doesn't really change the flavor of the brew at all, unlike brewing over ice.