# Slow chemex



## JPa (9 mo ago)

Hi everyone,
I’m a new member and I’d like to have your advice about my problem with the chemex:
I’m using paper filters and I don’t know what I do wrong since it takes me more than 8 minutes to finish the coffee. I grind the beans in the right measure, but the water falls down really really slowly. I watched a lot of videos and I see that it’s not that slow. What can be wrong? Thank you for any of your suggestions.
Giulia.


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## MWJB (Feb 28, 2012)

Hi Guilia,

I'm assuming the results don't taste very good? Brew time is a very poor indicator of extraction, but 8 min seems outside the norm.

How big are your brews and can you explain how fast you add the water?

If the Chemex gets very full, then the paper can adhere to the walls and sag into the spout causing an airlock, which slows down the brew. The easiest way to prevent this is to grind coarser and add the water in pulses. I sometimes put a steel straw in the spout to keep an airway open, if I think I'm risking an airlock.

Which grinder are you using & what is the setting?


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## JPa (9 mo ago)

MWJB said:


> Hi Guilia,
> 
> I'm assuming the results don't taste very good? Brew time is a very poor indicator of extraction, but 8 min seems outside the norm.
> 
> ...


Hi, thank you for your time. I’m actually careful on pouring the water, the bloom time, and ratio warms very good, I’m grinding in the right way, using hario grinder that works perfectly, even though I pour slowly the water, it’s frustrating that it go down slowly and drop by drop. I even tried to use a chopstick but it doesn’t work… I’m thinking to buy a cotton filter. Could it be a solution?


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## MWJB (Feb 28, 2012)

JPa said:


> Hi, thank you for your time. I’m actually careful on pouring the water, the bloom time, and ratio warms very good, I’m grinding in the right way, using hario grinder that works perfectly, even though I pour slowly the water, it’s frustrating that it go down slowly and drop by drop. I even tried to use a chopstick but it doesn’t work… I’m thinking to buy a cotton filter. Could it be a solution?


OK, can you tell us what it is you actually do please?

"Careful", "very good" & "the right way" don't give us any datums for what you are actually doing.

Tell us the grinder, grind setting, dose weight, bloom weight & time, total water weight & how you add it/when the last water goes in, the time when you see the last water drain through the bed and taste score. A video would also be very helpful.

I have no idea how a chopstick could help.

I have no experience with cotton filters but you should be able to brew just fine with paper filters.Chenging filters won't cure your current issue.


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## JPa (9 mo ago)

MWJB said:


> OK, can you tell us what it is you actually do please?
> 
> "Careful", "very good" & "the right way" don't give us any datums for what you are actually doing.
> 
> ...


Thank you for your answer. I’m using hario manual grinder, the grind is medium. I’m using 18 gr of coffee for a total 280 gr of water. For blooming, I pour 36 gr of water and wait 30 seconds, then I pour 120 gr of water and from now it starts the problem, the water goes down drop by drop and after almost 3 minutes, the water still there and if I pour more water, I still have a “lake” of water that stuck in the filter. I dramatically try to stir the water, but doesn’t change anything. The chopstick was a suggestion from James Hoffman. For a couple of seconds (literally), the water goes down straight, but then, again, drop by drop.
Should I grind more corse?


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## MWJB (Feb 28, 2012)

JPa said:


> Thank you for your answer. I’m using hario manual grinder, the grind is medium. I’m using 18 gr of coffee for a total 280 gr of water. For blooming, I pour 36 gr of water and wait 30 seconds, then I pour 120 gr of water and from now it starts the problem, the water goes down drop by drop and after almost 3 minutes, the water still there and if I pour more water, I still have a “lake” of water that stuck in the filter. I dramatically try to stir the water, but doesn’t change anything. The chopstick was a suggestion from James Hoffman. For a couple of seconds (literally), the water goes down straight, but then, again, drop by drop.
> Should I grind more corse?


18g coffee to 280g of water is unlikley to result in a normal extraction. I'd be expecting to use more like 270g water.

Stirring the water won't help..

Grind more coarsely.

I'd start by blooming 67g for 40s, then add another 67g every 40s

0:00 bloom 67g
00:40 add up to 134g,
1:20 add up to 200g,
2:00 add up to 270g

Bloom in a spiral, any pours that start with a dry bed pour in a spiral, if there is liquid sitting over the bed when a pour starts, pour straight down the middle. Each pour should take 20-30s.

Report back.


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## JPa (9 mo ago)

MWJB said:


> 18g coffee to 280g of water is unlikley to result in a normal extraction. I'd be expecting to use more like 270g water.
> 
> Stirring the water won't help..
> 
> ...


Thank you for this very kind advice. I’ll try tomorrow with this. Thank you very much


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## MWJB (Feb 28, 2012)

Sorry, I misread 280g as 180g. Don't know how that happened...however, 270g or 280g shouldn't make that much difference, both will extract OK (at the right grind & pour). Either way, let me know how it goes


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## JPa (9 mo ago)

MWJB said:


> Sorry, I misread 280g as 180g. Don't know how that happened...however, 270g or 280g shouldn't make that much difference, both will extract OK (at the right grind & pour). Either way, let me know how it goes


Thank you again, but, I’m just brewing my coffee and even with your kind suggestions, it doesn’t work. I ground the coffee more course but it doesn’t work, it just goes down drop by drop.


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## MWJB (Feb 28, 2012)

JPa said:


> Thank you again, but, I’m just brewing my coffee and even with your kind suggestions, it doesn’t work. I ground the coffee more course but it doesn’t work, it just goes down drop by drop.


How many clicks are you from locked burrs, is it a Hario Slim? If so, I'd aim to be 10-11 clicks.

It definitely does work. 41 brews with 17.6g to 264g coffee averaged 3:43 +/-30s all poured much slower(1.23g/sec) than what I suggested (1.68g/sec).

Would you be able to make a video, it might give a clue as to what the issue is?


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## JPa (9 mo ago)

MWJB said:


> How many clicks are you from locked burrs, is it a Hario Slim? If so, I'd aim to be 10-11 clicks.
> 
> It definitely does work. 41 brews with 17.6g to 264g coffee averaged 3:43 +/-30s all poured much slower(1.23g/sec) than what I suggested (1.68g/sec).
> 
> Would you be able to make a video, it might give a clue as to what the issue is?


Thank you for your help. Now I set the grinder with your suggestions. I’ll try tomorrow morning and I’ll let you know. I’ll also try to make a video, but I’ll see if I’ll be able since I’m alone and I’m not that able in video making 😊


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## MWJB (Feb 28, 2012)

JPa said:


> Thank you for your help. Now I set the grinder with your suggestions. I’ll try tomorrow morning and I’ll let you know. I’ll also try to make a video, but I’ll see if I’ll be able since I’m alone and I’m not that able in video making 😊


I just made a Chemex brew 18g at 10clicks on Hario Slim.
0:00 pour up to 67g in ~25s, spirals
0:40 pour up to 134g started in spiral then down middle
1:20 pour up to 200g down middle
2:00 pour up to 270g down middle

Dry bed 3:11.

OK brew, nominal extraction for this coffee, but I could go a click finer, I reckon.

Maybe the only difference between your brew & mine is that I used a Hario 02 paper (no Chemex papers).


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## MWJB (Feb 28, 2012)

MWJB said:


> I just made a Chemex brew 18g at 10clicks on Hario Slim.
> 0:00 pour up to 67g in ~25s, spirals
> 0:40 pour up to 134g started in spiral then down middle
> 1:20 pour up to 200g down middle
> ...


2nd brew, one click finer, another % on extraction, dry bed at 3:24. A pretty good brew from this coffee & the Chemex.


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## JPa (9 mo ago)

MWJB said:


> I just made a Chemex brew 18g at 10clicks on Hario Slim.
> 0:00 pour up to 67g in ~25s, spirals
> 0:40 pour up to 134g started in spiral then down middle
> 1:20 pour up to 200g down middle
> ...


I think I understand what the problem is: I followed all your suggestions, but it still going slow, in a desperate action, I pull the filter and it started to go in a proper way, so I think that the filter stuck on the surface that doesn’t allow the water to go down properly. I’ll try with the hario 02 paper too.


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