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Hario V60 vs. Chemex design and techniques

Postby bigbad on Wed May 23, 2012 10:13 pm

I've been experimenting a lot with the V60 and Chemex lately to find a technique that makes the most scientific sense.

I find that everybody has a different technique and method for pourovers, but none of them can break down every movement. They just do it, because 1) it's the way they were taught and/or 2) it simply "works" for them.

I have a couple technical questions... forgive me if my thoughts come off scrambled and disorganized.

What do you think of pouring on the outside of the grinds? On one hand, this can cause channeling. On the other hand, the grinds on the outside simply don't get the same extraction as the grinds in the middle, because it's the first to surface during the drawdown.

Pouring down the outside of the grinds, promotes mudslides, avalanches, bottlenecking, whatever you wanna call it. In other words, once all the water draws down, the grinds are gonna be flat and clogged, as opposed to an inverted cone shape.

People seem to have negative things to say about clogging the filter, because it can slow down the drawdown phase and overextract the grinds.

I had the opportunity to train with Stumptown recently, and the rep actually sought out a flat coffee bed, upon completion of the pourover. His reasoning was that you wanna extract the water through a bed of coffee a la espresso.

I could see some merit in his argument. It seems to be the only way to ensure that all grinds are extracted, as opposed to when you have grinds that draw down as an inverted cone, some grinds are inevitably left high and dry.

That said, I'm sure the flat bed of coffee grinds is not gonna be ideal for a cone shaped filter, not only because it goes against the shape of the cone, but because everytime you pour near the filter walls, you're gonna get some side channeling.

I think the flat bed of coffee grinds would be awesome for the kalita wave dripper, which on a scientific level, kicks the V60's ass. From the rippled filters that discourage side channeling, to the flat bottom, it makes a whole lot of sense. But I haven't used the kalita wave dripper yet, and the cafe I work at only features the V60 and Chem for pourovers right now, so I'm just focused on dialing in a scientifically sound technique.

Either drawdown (flat bed vs inverted cone) seems to have its own pros/cons. In the end, it seems like the cone filter is a flawed design from the getgo. I guess my question is, which seems to be the lesser of the evils? And why?
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Postby Sam21 on Thu May 24, 2012 11:53 am

I have a small Kalita on the way, but use my V60 daily. I use Barismo's method and keep my bed of coffee very low with a steady, constant, and SLOOOOOW pour. I have a flow restrictor, so I can keep the flow to steady, but light stream in circles. I leave space between the outer walls of the grounds bed and my stream. The resulting coffee bed is like a very shallow cup. I use a long pour and aim for 20 seconds of drawdown, so that the "high and dry" grounds are not left out for very long at all. The walls of the resulting grounds bed are only a few CM high.

By design, the flat bed makes more sense for extraction, but the low bed/consistent pour method works very well for cone brewers. Terroir recommends a similar approach to the Chemex and V60. Timed calculated pours that keep the slurry very low in the filter. They refill the bed of grounds as soon as it begins lowering to reduce any amount of time that some coffee is left out of the water. This is their approach to cone filter brewing and it one that I think works quite well.

That said, I look forward to trying out the Kalita a bit more and experimenting with the 155!
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Postby oktyone on Thu May 24, 2012 9:16 pm

If having a flat bed is so critical, i wonder if pouring through an aeropress would make any difference, you would probably need to hacksaw it down to about a quarter of its height, otherwise the stream would be too high up and create too much turbulence..drip speed could also be an issue, but likely easily solved by blocking areas in the aeropress filter holder.

Also, i wonder how a dripper design such as this one would fit into all of these coffee dripping theories:

It got me so curious i had to order one, but still hasn't arrived, i'm not a big fan of cloth filters, but it's supposed to work with V60-02 filters as well, it has four small holes distributed evenly at the bottom.
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Postby aecletec on Fri May 25, 2012 5:32 am

I've tried pouring through an aeropress but felt that a special filter would be needed as the flow was too slow even on cloth (syphon filter) or the old coarse disk filter.
Scientific sense would imply test and re-testing of trials. Test for yourself - I find agitating the chemex brew with a swirl of the brewer helps keep all of the grounds wet and ends up with a flat bed even - similar to a slow pour method around the sides. The only significant difference I've found is less bitterness with the swirled than slow poured brew (same ratios, brew time IIRC - I've stopped timing a while ago due to consistency of the method) but the same body/richness of flavour. Still in my early days but my advice would be "test, test, test!".

On the cone - if you look at the flow of coffee out of the chemex filter it doesn't just come from the tip, the tip is where the water flows around but the rest of the filter is permeable... on a flat bottomed filter the coffee can drip out of anywhere (as per vids I've seen, never tried one) so how would that ensure evenness? I'm not arguing for or against either style but a shaped permeable filter with a large hole opening may not restrict flow as much as is said.
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Postby bigbad on Fri May 25, 2012 11:54 am

oktyone wrote:If having a flat bed is so critical, i wonder if pouring through an aeropress would make any difference, you would probably need to hacksaw it down to about a quarter of its height, otherwise the stream would be too high up and create too much turbulence..drip speed could also be an issue, but likely easily solved by blocking areas in the aeropress filter holder.

Also, i wonder how a dripper design such as this one would fit into all of these coffee dripping theories:
<video>

It got me so curious i had to order one, but still hasn't arrived, i'm not a big fan of cloth filters, but it's supposed to work with V60-02 filters as well, it has four small holes distributed evenly at the bottom.


The aeropress is not really a pourover device. It's more like a french press/espresso hybrid, but I know what you mean.

I would opt for the kalita wave if you wanna experiment with flat bed coffee geometry. I'm gonna be getting one pretty soon, so looking forward to it.

As for the video, it seems like another cool dripper design, but again, I don't see how it solves the issue with uneven extraction. It's a donut shaped filter, so it looks like it might even leave more grinds high and dry due to the convex cone protruding through the middle. But it's definitely an interesting twist on the cone shaped pourover. The manual pouring seems a little simplified since it looks like you just have to follow the donut pattern, but then again, I guess you never know until you fully experiment.
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Postby yakster on Fri May 25, 2012 12:20 pm

This thread had me thinking of trying to attach the spray head from a drip coffee maker to the end of my pouring kettle, or just putting a handle on the Aeropress cap to hold over the bed to disperse the flow. I have seen people hold a spoon over the coffee bed and pour onto the spoon to break the landing and help disperse the water a bit so that it doesn't disturb the coffee as much.

When I do pour-over, though, I try and pour in spirals and keep the edges of the coffee bed in the Chemex from getting high-and-dry. Sometimes I'll take a spoon and gently push the grounds at the edge towards the center, but usually I don't bother.

I'm looking forward to trying a Kalita Wave out for a week in a Green Coffee Buying Club traveling road show to see how a flat-bottomed pour-over compares.
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Postby bigbad on Fri May 25, 2012 12:21 pm

aecletec wrote:I've tried pouring through an aeropress but felt that a special filter would be needed as the flow was too slow even on cloth (syphon filter) or the old coarse disk filter.
Scientific sense would imply test and re-testing of trials. Test for yourself - I find agitating the chemex brew with a swirl of the brewer helps keep all of the grounds wet and ends up with a flat bed even - similar to a slow pour method around the sides. The only significant difference I've found is less bitterness with the swirled than slow poured brew (same ratios, brew time IIRC - I've stopped timing a while ago due to consistency of the method) but the same body/richness of flavour. Still in my early days but my advice would be "test, test, test!".

On the cone - if you look at the flow of coffee out of the chemex filter it doesn't just come from the tip, the tip is where the water flows around but the rest of the filter is permeable... on a flat bottomed filter the coffee can drip out of anywhere (as per vids I've seen, never tried one) so how would that ensure evenness? I'm not arguing for or against either style but a shaped permeable filter with a large hole opening may not restrict flow as much as is said.


I've never thought of picking up the Chemex and actually swirling it. Interesting.

I know there are some folks who advocate agitating the grinds or scraping off high and dry grinds with a demitasse spoon of sorts, during different phases of the extraction.

The flat bottomed filter ensures more evenness for flat coffee bed geometry. Your pour will need to be adjusted so that you create an even stream, as opposed to the traditional centered pour of the cone designs. This way, the extraction will even out as much as possible.

If you've seen the kalita wave dripper's filters, it's rippled on the sides, and it's supposed to 1) offer insulation and 2) prevent water from permeating through the sides.

It's like espresso extraction. You want a flat bed of coffee in a flat basket for evenness.
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Postby aecletec on Sat May 26, 2012 7:08 am

bigbad wrote:I've never thought of picking up the Chemex and actually swirling it. Interesting.

I know there are some folks who advocate agitating the grinds or scraping off high and dry grinds with a demitasse spoon of sorts, during different phases of the extraction.

The flat bottomed filter ensures more evenness for flat coffee bed geometry. Your pour will need to be adjusted so that you create an even stream, as opposed to the traditional centered pour of the cone designs. This way, the extraction will even out as much as possible.

If you've seen the kalita wave dripper's filters, it's rippled on the sides, and it's supposed to 1) offer insulation and 2) prevent water from permeating through the sides.

It's like espresso extraction. You want a flat bed of coffee in a flat basket for evenness.

The flow of the water with pouring and the movement of water through the filter (e.g. on a glass device http://www.youtube.com/watch?v=mupueSMHBJQ) shows that it's not like espresso - a compacted layer of coffee being the barrier to water pushed through it - we can see that on a good espresso extraction the liquid exiting the filter is distributed evenly but a la Nick Cho's video we can see this doesn't happen on his kalita wave. What we see instead is that water flows out of the filter at multiple locations (also the grounds continue bubbling for a long time into the "brew phase"). Perhaps water is flowing evenly and the streams aggregate at different points but this seems unlikely given the changing location and drip/flow rate seen.

A flat bed perhaps enables more channeling as water can 'avoid' extracting solubles - e.g. my mental picture is that bloomed coffee may lead to slower flow as the water is engaging with coffee particles instead of moving around gas bubbles. If water is forced to engage with coffee by some means of restriction then perhaps the brew may be more even (e.g. with a thought to the clever dripper).

However, if coffee particles are suspended during the brew and water can escape around the grounds (e.g. they are not compacted and there is a reasonable area of filter open to flow) then I think that filter shape may be less important than pour and flow dynamics.
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Postby bigbad on Mon May 28, 2012 3:34 pm

aecletec wrote:The flow of the water with pouring and the movement of water through the filter (e.g. on a glass device http://www.youtube.com/watch?v=mupueSMHBJQ) shows that it's not like espresso - a compacted layer of coffee being the barrier to water pushed through it - we can see that on a good espresso extraction the liquid exiting the filter is distributed evenly but a la Nick Cho's video we can see this doesn't happen on his kalita wave. What we see instead is that water flows out of the filter at multiple locations (also the grounds continue bubbling for a long time into the "brew phase"). Perhaps water is flowing evenly and the streams aggregate at different points but this seems unlikely given the changing location and drip/flow rate seen.

A flat bed perhaps enables more channeling as water can 'avoid' extracting solubles - e.g. my mental picture is that bloomed coffee may lead to slower flow as the water is engaging with coffee particles instead of moving around gas bubbles. If water is forced to engage with coffee by some means of restriction then perhaps the brew may be more even (e.g. with a thought to the clever dripper).

However, if coffee particles are suspended during the brew and water can escape around the grounds (e.g. they are not compacted and there is a reasonable area of filter open to flow) then I think that filter shape may be less important than pour and flow dynamics.


You can't really compare the visual cues of extracting espresso and drip coffee. If you've ever tried to extract espresso with less than 9 bars, you'll notice you don't get the nice, syrupy funnel.

That said, you make great points. I think you can force some "restriction" by playing around with the grind, though.

At the end of the day, neither brew options are perfect. I just find that the Kalita is more scientifically solid. Flat filter bottom + flat bed of coffee + rippled filter to discourage side permeation (at least theoretically... I would like a scientific explanation of this phenomenon) > conical filter + choice of high/dry grounds or flat bed of coffee (which goes against conical shape).
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Postby bigbad on Mon May 28, 2012 5:43 pm

oktyone wrote:Also, i wonder how a dripper design such as this one would fit into all of these coffee dripping theories:


BTW love that precision kettle/pitcher with the thermometer.
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