Chemex: why you should hate it

[Scott Rao]

Everywhere I go this month, I can't seem to avoid conversations about Chemex. People keep asking me how best to make them. Others share their voodoo-like pouring techniques. A certain WBC champ loves his chemex and made a video about it, and a certain otherwise-awesome coffee company just yesterday served me a Chemex that was very unevenly extracted, resulting in a cup that was rather light in brew strength yet simultaneously bitter, astringent, and overextracted. It was a waste of beautiful, expensive coffee beans that deserved a better fate.

This seeming renaissance of the Chemex is unfortunate, because I don't really like Chemex coffee. Neither should you. Here's why:

Chemex, like any brewing method, has the potential to extract the desired amount of mass from the grounds (let's say 20%) and to create a cup of the desired brew strength (let's say 1.4%). Some people really like the extreme amount of flavor clarity created by the thick Chemex filter, at the expense of the coffee's body, of course. Fair enough.

What no one seems to notice is that it is nearly impossible to extract that 20% EVENLY from the coffee bed. The Chemex habitually overextracts from the grounds near the bottom of the filter (and generally from the center, though that depends on your pouring method.) And the Chemex underextracts from those grounds at the periphery (those grounds that end up sticking to the filter high up the filter walls.)

Think about it: The grounds that stick to the filter high up its walls stop participating in the extraction process perhaps two minutes (or whatever) before the grounds at the bottom do.

The Chemex is also flawed because a lot of heat is lost through the open top during the extraction process, but that's trivial compared to the under/overextraction problem.

If you insist on making Chemex coffee (perhaps you appreciate visual aesthetics but have no taste buds), please do the following:

-Use almost-boiling water.
-Pour some water in (approx 2g water/ 1g grounds is a good guess) and churn the slurry with a spoon to make sure that all of the grounds get wet at about the same time (thus starting the extraction clock at about the same time for all grounds.)
-Pour in many small stages, the more the better, over the course of the brew.
-Try to keep the "high water mark" of the coffee slurry in the filter as low as possible.
-Stir frequently. In truth, stirring when brewing coffee is best avoided because it accelerates the rate of extraction and is inherently inconsistent, unless you are a machine.

-I won't write how much and when to stir, but if you buy into what I've written, and you think hard about it, there is a logical way to optimize the effect of stirring.

-If all goes well, the spent grounds should be either flattish or dome-ish in the filter.

[Klaus]

Hi Scott.

I look forward to see the responses to this, as people in general don't like to be told what to like

Just to open up a little bit, I'd have to say (and I am not trying to stir things up here guys and gals!) that I often found that Americans tend to be more focused on body in filter coffee whereas I find that Northern Europeans tend to focus more on the aromas. I don't drink my Chemex coffee because I want body - quite the opposite. I like the clarity of the cup as a contrast to my usual french press (where the new techniques advocated first by Tim Wendelboe has been a great improvement). So perhaps the Chemex could have it's place for some of us? And perhaps even for those who have taste buds.

I agree that the Chemex is not the perfect brewing system and that some grounds will possibly over-extract near the bottom. I also found that with a grinder that's not perfectly sharp there can be quite a lot of bitterness. Regarding heat, though I've found that near-boiling gives off more bitterness than 95 degrees Celcius water.

Just my 1,2 Danish Kroner (or 2 cents...)

[James Hoffmann]

I seem to have been "called out" here, though I am not sure why you couldn't just use my name?

I hope this does generate discussion, because I want to learn more. I don't really feel I ought to justify myself, or the video. The technique I arrived at was a mixture of public domain knowledge, a quest for ease and repeatability and a brew that charted well and I often thought was a great presentation of the coffee. I wasn't trying to profit from public domain knowledge, I just wanted people to brew better coffee and if the one thing they took from the video was brewing on scales then I would have been happy.

I do see your point about not pushing an idea or a technique out there until I consider it perfect/correct but I am not sure I would ever really get there for any method of making coffee. How long should one roast and profile a coffee before releasing it, and once released is it somehow taboo to keep working on improving it as you gain more experience. Discussion generates progression and hopefully at the end of this we all will be brewing better coffee (in both absolute extraction terms and tasty, delicious and fun terms).

This discussion could also be taken down the road of the aesthetic muddling the scientific (I am looking at you Naked Portafilters), with the cone of spent grounds somehow seeming more desirable than it really is.

Every single way I brew coffee has changed in the last 5 years, and I really hope that in 5 years time we'll look back on what both I filmed and you wrote and laugh (merrily) at how foolish we once were.

[MarkG]

I think in the main that most of us mere mortals like to watch, and do learn from 'instructional' videos made by the pros. James' video didn't appear to suggest that the Chemex was the be all and end all of brewing, nor that he considered his method to be perfect - just that he very much enjoyed it and wanted to share his passion. I thought he achieved just that.

It strikes me that we don't know (and as James suggested, may never know) what perfection is yet, and in any case it is surely subjective? Happiness is where we each find it.

Voodoo under the SQM rail arches eh?

[Andy Schecter]

Whoa, "hate" is a pretty strong word.

What no one seems to notice is that it is nearly impossible to extract that 20% EVENLY from the coffee bed. The Chemex habitually overextracts from the grounds near the bottom of the filter

This is a bit ironic: when I first read the passage in your book where you theorize that a portafilter basket shaped like a truncated cone would extract more evenly, I thought, "Oh, like a Chemex filter!" But I think your point about underextracted grounds that end up high and dry early in the Chemex extraction is a good one. And undoubtedly a Raomatic shower head would keep most of the grounds participating in the extraction for a much longer period.

A possible hybrid (and somewhat tedious) technique would involve infusing one's coffee/water mixture for ~2 minutes in an insulated vessel like the Eva Solo (!), and then filtering through the Chemex.

stirring when brewing coffee is best avoided because it accelerates the rate of extraction

Best avoided? With careful stirring and the proper grind, seems like one would get very even extraction. This might apply even if you don't have a paddle carved by Hattori Hanzō from bamboo harvested in virgin Japanese mountain forests.

-I won't write how much and when to stir, but if you buy into what I've written, and you think hard about it, there is a logical way to optimize the effect of stirring.

Not sure why you're suddenly being coy here, but are you suggesting a brief stir after each water addition?

[nick]

Interesting thread, but very weird as well.

Scott, every thing you wrote criticizing the Chemex is true of most all drip-style brewing methods.

The top layer will always over extract, or at least, extract more than the lower layers. The lowest layers will never encounter water in the same way as the top layers.

The extraction dynamic will differ a bit from cone to flat-bottomed filters, but it is what it is. To paraphrase the beginning of your fourth paragraph, it's impossible to extract perfectly evenly from ANY directional-brewing system. Not from Chemex, not from my Technivorm, not from our Fetco Extractor at the shop... not from espresso. Not even from a single-basket, Scott.

Makes me wonder... why do you think that the "Chemex habitually overextracts from the grounds near the bottom of the filter?" Is this based on theory, or on empirical data?

But it's gotta be said: you don't drink a percentage. You don't drink heat loss. You drink the coffee. Obviously, there's a link, but unlike the Clover brewer, people haven't been extolling the virtues of the Chemex because of the system itself... they like the resulting cup. You can shoot whatever holes you want into the theories around it... doesn't make the coffee taste worse.

For the record, I haven't made a Chemex in 3 years (just haven't had one around... I think Aaron Ultimo broke mine). The only time since then that I've had a cup brewed from a Chemex was brewed by the lovely and talented Sarah Kluth... the 1st-place Rwanda auction lot (Golden Cup) from a couple years ago. It was a badass cup.

Then again, you're in Chicago... you could check Sarah for taste buds.

Nick

P.S. Time stamp says 12:54am Chicago-time. Did you think that it'd be a good time for a manifesto?

[trish]

This reminds me of when Kevin Knox (Darrin Daniel or Peter G can correct me if I'm misrepresenting his stance) made the observation that cupcake shaped brewers were always going to be better than cone...because the coffee out of tip of the cone was going to be enough to kill the whole cup.
But based on that larger surface area at the bottom, wouldn't you also have MORE overextracted coffee to mix in with good stuff?

So, by using a cone, you're actually reducing the possibility of overextracted fines at the tip?
You're just doing the best you can for the coffee...creating a small-batch that you can babysit and bring to its best potential.

If you don't feel like talking about cupcake filter forms, we could just talk about cupcakes.

[Scott Rao]

Wow. Maybe I should have waited til I was less tired before posting (I had just arrived in New Zealand on an overnight flight. Not sure why Nick thinks I'm in Chicago?)

I often found that Americans tend to be more focused on body in filter coffee whereas I find that Northern Europeans tend to focus more on the aromas.

Klaus, I'm sure your taste buds are wonderful. And thank you for the point about regional preferences regarding aroma, body, and flavor clarity. Hopefully I was clear enough that my main issue with the Chemex is not the clear, light-bodied cup it produces, but rather how difficult the Chemex design makes it to extract evenly.

I do see your point about not pushing an idea or a technique out there until I consider it perfect/correct but I am not sure I would ever really get there for any method of making coffee.

James, I'm sorry that you take some of my comments more personally than they are meant to be. I don't mean any disrespect. And of course I don't expect any of us to wait until we are perfect before teaching a technique. Otherwise I never could have published a book about making coffee. I've just recently been frustrated by the amount of speculating that we do in the specialty coffee industry (I'm guilty of it too) and am hoping we'll spend more time testing and verifying (in the Schectermatic vein) before publishing or teaching our techniques.

James' video didn't appear to suggest that the Chemex was the be all and end all of brewing, nor that he considered his method to be perfect - just that he very much enjoyed it and wanted to share his passion. I thought he achieved just that.

All I had written here about James was that he loves his Chemex and made a video about it.

Scott, every thing you wrote criticizing the Chemex is true of most all drip-style brewing methods.

Nick, I disagree; not all drip brewing systems will extract unevenly. Basket shape, stirring, the velocity of the water as it sprays onto the coffee bed, and other factors can be manipulated to create an even extraction throughout the whole coffee bed. (Please understand, I'm not saying every single cubic cm of grounds extract identically. But if you can tolerate, say, a 19% extraction from one area and a 21% from another area, that should not be difficult to do. Chemex, unfortunately, does extract much more unevenly than your Fetco, for instance.)

Makes me wonder... why do you think that the "Chemex habitually overextracts from the grounds near the bottom of the filter?" Is this based on theory, or on empirical data?

Empirical.

But it's gotta be said: you don't drink a percentage. You don't drink heat loss. You drink the coffee. Obviously, there's a link, but unlike the Clover brewer, people haven't been extolling the virtues of the Chemex because of the system itself... they like the resulting cup. You can shoot whatever holes you want into the theories around it... doesn't make the coffee taste worse.

Nick, this is part of my gripe. Yes, taste is all that matters, but taste is very difficult to discuss with precision. Using objective measurement as a guide, without being a slave to the data, can be very useful for improving our coffee and our ability to discuss how to make it.

However, heat loss, extraction %, etc. all have to be understood and addressed if you want to consistently make beautiful coffee (and not just the accidental good cup here and there.) But the flaws in the Chemex design DO make the coffee taste worse. Come visit me one day in Montreal and I'll happily make you dozens of different drip coffees and apply what I'm talking about. I won't bother you with theory and we'll just taste blind and let you decide which cups you like (though you'll have to pay for dinner.)

A possible hybrid (and somewhat tedious) technique would involve infusing one's coffee/water mixture for ~2 minutes in an insulated vessel like the Eva Solo (!), and then filtering through the Chemex.

Andy, I'm sorry I wrote 'hate.' I feel like I've broken some unspoken posting code.
As for post-filtering, yes, I agree, it's a good idea. I play with that from time to time just to demonstrate for customers or employees how various filters affect the final cup.

Best avoided? With careful stirring and the proper grind, seems like one would get very even extraction. This might apply even if you don't have a paddle carved by Hattori Hanzō from bamboo harvested in virgin Japanese mountain forests.

Hmmm, maybe I chose my words poorly (again). Of course I believe in the usefulness of stirring, as I even advised stirring when making a Chemex. What I should have written is that it is challenging to stir identically every brew, so it is probably best to minimize dependence on stirring. Ideal, to me, would be to avoid manual stirring and to substitute some sort of automatic, repeatable source of agitation.

For instance, when designing the Raomatic, I found that increasing the distance from the sprayhead to the grounds increased the agitation of the grounds in the slurry (due to gravity accelerating the velocity of the falling water.) The extra agitation accomplished several things at once: it accelerated extraction, enhanced the evenness of the extraction, and negated the need for stirring. (As an aside, I also found I could enhance the evenness of the extraction from my Technivorm by modifying it and moving the brew basket several inches lower. Unfortunately the Technivorm doesn't offer the kind of sophisticated temperature control that the $20 Raomatic does, and this mod cools the Technivorm brewing water too much.)

Not sure why you're suddenly being coy here, but are you suggesting a brief stir after each water addition?

Yes, more or less. Sorry for coyness. I thought you liked coy and that was why you keep your Eva Solo's neoprene dress only half-zipped?

[Peter G]

Nothing like a good old fashioned rant to spur a little controversy!

Let me throw a few things out there:

On "Uneven Extractions": Frequently, rants against brewing styles or devices includes the "uneven extraction" idea. Whether Chemex, Melitta, single portafilter basket, whatever; claiming "uneven extraction" is a self-evident way to smack down a brewing paradigm. Obviously, an "even" extraction is better than an "uneven" one, right?

Not so fast. In food, unevenness is often a virtue. Take steak. A well cooked steak is overcooked on the outside (almost charred) and nearly raw on the inside. The in between areas are, umm, in between. This unevenness is delicious. It is easy to cook a steak evenly throughout- you just boil it. A boiled steak is cooked pretty evenly all the way through. Enjoy your evenly cooked dinner. The same is true for many foods. The cooking methods of grilling, baking, and sauteing produce uneven results as a matter of course. Boiling, braising and sous vide (the ultimate in evenness) are ways to cook with more uniformity. All have their different uses, for different foods, and different dishes.

Back to coffee. It seems that many have accepted the notion that the ultimate grind is perfectly uniform, the ultimate espresso machine is perfectly temperature-stable, and the perfect drip-brewer extracts perfectly evenly; and the closer you are to this ideal "evenness" the better your coffee will be. There is little evidence to support this idea. It is entirely possible that the uneven extraction that results from variable particle sizes, temperature variation, and extraction efficiency lends complexity to the cup, by mixing the differing flavors that come from deep extraction, light extraction, and the places in between. It is my feeling that this is exactly the beauty of the wide variety of brewing paradigms in the world; the complex profile of extraction efficiency, temperature variation, etc. give personality to the various brewers and make it possible to perceive differences in, and have a preference for, Chemex vs. Melitta vs. vacpot vs. Eva Solo.....

Don't get me wrong, I am not advocating for "unevenness" either. My feeling is that different coffees submit themselves to extraction in different ways. Let's really understand extraction profiles and the way different coffees perform within those extraction profiles before we start railing against particular brewers, along with "empirical proof" which is really nothing more than speculation based on dogmatic assumptions. Which brings me to my next subject:

On Dogma: We've got this unfortunate habit in coffee (indeed, many foodies seem to have this disease). It seems that many of the best and brightest in coffee turn their considerable intelligence towards proving what is wrong about coffee, rather than what is right. Often, this takes the form of "proving" that certain brewing methodologies, roasting protocols, processing methods, etc. are inferior to all others. These proofs are usually based on anecdotal or intuitive arguments, which once examined, fall apart. "Proving" that something is bad is the territory of blowhards, shallow minds, and religious fanatics. That is the sort of dogmatic reasoning that keeps us behind. Humble, curious exploration of coffee is what pushes us forward. There is nothing wrong with challenging conventional wisdom, but when you start trumpeting "proof" and "truth", you discredit yourself immediately. I submit it is a more useful use of energy to create rather than destroy. Therefore, I challenge those who are tempted to proclaim anything as "wrong" to instead work on making something useful. To do anything less is insulting to your own intelligence.

I have become so tired of those who find fault with clovers, vacpots, cone filters, French Presses, espresso machines, whatever. I have spent too many hours listening to people explaining their reasons why a particular brewing style (or roast, or process, or whatever) has disappointed them. I don't care to listen to your logic about why something cannot work. I don't give a s***. Instead, please figure out how to make awesome coffee, and tell me about THAT. Please include as much information as you can. Some of the brightest minds in coffee (oh man, I could make a list) spend all of their time railing against espresso, or DP ethiopians, or clovers, or whatever. It's a waste of intelligence and time.

Scott, your work in developing better systems for extracting coffee sounds fascinating. Don't hide that good work behind diatribes against a little, simple brewing device. You're better than that!

On Cone Filters: I have long heard the intuitive criticism against cone filters (Trish, I always associate it with Ric Rhinehart, but it might indeed have come from Kevin Knox as well). The argument goes that the little triangle of coffee at the bottom of the inverted cone gets overextracted, while the top layer gets underextracted. I've never seen this proven, it is always presented as an obvious, intuitive truth. In order to really go down this road, you would have to: 1. prove that this over- and under- extraction really happens and 2. prove that this over- and under- extraction is always a bad thing for coffee. I have never seen any attempt at such a study, in fact I can't imagine doing it, it would be so complex.

In my experience, water doesn't just flow down the cone and out the tip. Instead, it flows down and diagonal, brewed coffee exiting the filter paper well above the tip, bypassing it entirely. Also, we know that water's ability to extract coffee solubles is highly dependent on how much soluble material is already in the water. It is entirely possible that once water reaches the bottom of the cone, it is so full of solubles that it does a poor job of extracting the coffee at the bottom of the filter, therefore mitigating any overextracting effect there. One could conceivably make a bunch of different chemex pots, using the variety of techniques folks use, dry out the spent grounds, and analyze how many solubles had been extracted at different points within the cone. You'd have to repeat the experiment with a wide variety of coffees and roasts, and correlate it all with taste data. In the end, you might indeed "prove" that the tip of the cone is "overextracted". You might even prove that most coffee drinkers prefer coffees out of a French Press, or whatever. At the end of the day, you would have spent a lot of energy trying to discredit a brewing device which we all know is capable of producing delicious coffee. Hollow victory if you ask me.

At the end of the day, Chemexes and Melittas do a great job at simplifying the task of hand-brewing small amounts of coffee, which is why they have become popular recently. A barista handcrafting a Chemex in full view of a coffee lover has so many advantages over a machine, no matter how sophisticated, brewing coffee in a "black box" environment, where the only interaction is with the brewed cup. James Hoffmann and others are working diligently on developing and popularizing good techniques to really master the complex art of brewing coffee this way.

I always enjoy sitting around drinking delicious coffee while others prove to me that it isn't, in fact, delicious. I always try to drink it all before they stop talking. More for me.

ALL THAT SAID: I have only recently gotten good at cone-extractions; I have found my Chemex, Bodum Kona, and Beehouse Dripper sometimes difficult to get great coffee out of. However, a little focus has helped me tremendously; mostly I have used cooler water to great effect. Stirring coarse grinds and leaving finer grinds unstirred have both helped too. I had an astonishingly good cup of Peruvian farmer Ariel Pajoy's coffee using a paper filter in a Bodum Kona and a slow pour from a lipped beaker.

Peter G

[MarkG]

Everywhere I go this month, I can't seem to avoid conversations about Chemex. People keep asking me how best to make them. Others share their voodoo-like pouring techniques. A certain WBC champ loves his chemex and made a video about it, and a certain otherwise-awesome coffee company just yesterday served me a Chemex that was very unevenly extracted, resulting in a cup that was rather light in brew strength yet simultaneously bitter, astringent, and overextracted. It was a waste of beautiful, expensive coffee beans that deserved a better fate.

James' video didn't appear to suggest that the Chemex was the be all and end all of brewing, nor that he considered his method to be perfect - just that he very much enjoyed it and wanted to share his passion. I thought he achieved just that.

All I had written here about James was that he loves his Chemex and made a video about it.

Point taken and fair enough, though without your subsequent comments, and if read in the context of the sentence it was contained within along with those around it, that wasn’t initially entirely clear- to me anyway.

Getting back to the subject, we don’t have a Chemex. We mainly use a Swiss gold filter in a pour over jug for any brewed coffee. How does that compare in terms of even extraction? I ask as a diehard espresso drinker who wants to get into more brewed coffee but rarely enjoys it as much as a decent shot.

[Aaron Ultimo]

I had a beautiful cup of Mauritania out of my Chemex this morning. Everyone around the table (experienced coffee drinkers all) were in agreement. Pure caramel and crisp acidity. I kinda like to think we have "tastebuds" but then again maybe we don't.

In fact, I am so convinced by the deliciousness that can come from it that I will be using Chemex to brew all of our morning coffee at Ultimo Coffee when we open. Peter, it brings me great joy to see your comments here on that and adds extra confirmation to our choice.

P.S. Nick, I don't know who broke you're Chemex, but it wasn't me. The Synesso on the other hand...

[Scott Rao]

Aaron and others, I really didn't think any professionals on coffeed would take genuine offense at the tastebuds comment. It, and the rest of the post, were meant to generate some lively conversation. If you are confident in your coffee knowledge and tasting ability, I cannot see why those words would matter to you.

Peter, I'm flabbergasted by your words.

First, the steak analogy is not applicable here.

I don't care to listen to your logic about why something cannot work. I don't give a s***. Instead, please figure out how to make awesome coffee, and tell me about THAT. Please include as much information as you can.

Scott, your work in developing better systems for extracting coffee sounds fascinating. Don't hide that good work behind diatribes against a little, simple brewing device. You're better than that!

Are you really implying that I spend too much time fixating on why things can't work, and that I'm hiding my work? As I recall, I spent 11 months crafting a how-to book (not a how-not-to book) and did my best to help others make better coffee. Given that you bought three books, you should know better.

Plus, I AM sharing my work in trying to make better coffee. I'm unclear on why you're hung up on my criticisms of Chemex but are ignoring my efforts to contribute to the how-to side. (please see last part of my initial post.) There are also many things you do not know, such as the enormous amount of time I spend everyday answering email questions from my readers in attempt to help them make better coffee, or the second book that is in the works.

Do you really not care about the relative benefits and drawbacks of various brewer designs? Is it really unreasonable to criticize what I believe is a poor design? Should I just use any old brewer and technique and just learn to appreciate the results, no matter how good or bad they are? That's perhaps a wonderful way to enjoy life but it's not an effective way for a professional to improve his or her results.

"Proving" that something is bad is the territory of blowhards, shallow minds, and religious fanatics.

Thankfully, proofs are also the territory of scientists and mathematicians, so I will refrain from believing you have just lumped me in with blowhards, shallow minds, and religious fanatics. Blowhard, maybe. But shallow? Religious fanatic? Hell, I'm much more fanatical about my tea than coffee.

Obviously, an "even" extraction is better than an "uneven" one, right?

On the macro level of the whole bed of grounds, yes, it is. And regardless of how hard I try to make my extractions more even, I know it will never be 100% even, so I'm really not worried about going too far, if such a thing exists.

At the end of the day, you would have spent a lot of energy trying to discredit a brewing device which we all know is capable of producing delicious coffee. Hollow victory if you ask me.

I pointed out its flaws, I offered a technique to try to compensate for some of the Chemex's flaws, and I DO NOT yet know it is capable of producing delicious coffee to my standards (at least without tremendous effort and modification, defeating its point of its simplistic design.)

Instead, please figure out how to make awesome coffee, and tell me about THAT. Please include as much information as you can.

Okay, fine. When I'm in Atlanta you can make me a Chemex. After you finish enjoying your cup I will tell you numerous ways you could have made your coffee better. I will include as much information as I can.

[Andy Schecter]

Hundreds of years ago, in a mountain monastery, two monks were arguing a point in Buddhist doctrine. One monk was so convinced that his point of view was correct that he asked to see the master for confirmation. After the monk passionately presented his case, the master nodded and said, "Yes, you're right."

When the second monk got wind of this he made straight for the master's quarters and argued his own point of view. The master listened, then nodded, saying, "Yes, you're right."

Well, the head monk had witnessed both meetings and was very frustrated. "Master, you said the first monk was right, but the second monk argued the opposite point of view. They can't both be right!"

The master nodded and said, "Yes, you're right!"

[nick]

My bad on the Chicago assumption.

Nick, this is part of my gripe. Yes, taste is all that matters, but taste is very difficult to discuss with precision.

But it's still all that matters.

That's what you don't seem to get. People who have posted on this thread seem to be saying is that they legitimately like the taste, as professionals, of the brew from a Chemex. You're bringing up all these theoretical reasons why it's flawed. Your reasons don't matter because taste is all that matters.

However, heat loss, extraction %, etc. all have to be understood and addressed if you want to consistently make beautiful coffee (and not just the accidental good cup here and there.) But the flaws in the Chemex design DO make the coffee taste worse.

Understood and addressed, yes. That's why Sarah Kluth's Chemex that she made for us (that I mentioned above) was so badass. Cuz she understands and addresses. Most importantly, she makes a badass Chemex that tastes awesome and taste is all that matters. And it wasn't an accident. The only thing that Sarah does accidentally is make all the coffeeboys out there swoooon.

Come visit me one day in Montreal and I'll happily make you dozens of different drip coffees and apply what I'm talking about. I won't bother you with theory and we'll just taste blind and let you decide which cups you like (though you'll have to pay for dinner.)

No thanks. We'd have dinner and I'd say something was delicious and you'd tell me why I should hate it.

Are you really implying that I spend too much time fixating on why things can't work, and that I'm hiding my work? As I recall, I spent 11 months crafting a how-to book (not a how-not-to book) and did my best to help others make better coffee. Given that you bought three books, you should know better.

Now we're getting into Caragayan territory. Peter's referring to your original post, not your life, and not your career. C'mon Scott, you know better.

I'm flabbergasted by the defensiveness in your response to Peter. It was you who felt compelled to pen a diatribe against the Chemex; which, I might point out, is the first and only time that you've started an opinionated thread in your 2+ years on Coffeed.com. You are, with your typed words, trying to accomplish something that has previously been limited to the realm of street-thug threats: "I'm gonna knock the taste outta yo mouth!"

Hate to say it, but this whole thread is a little suspicious. Mention of some "Raomatic" (which is apparently some contraption to drip water more evenly across the surface of a manual-brew coffee bed) makes me wonder if this is merely trying to plant seeds of doubt in order to increase the marketability of some product or device. I obviously could be wrong, but there's something odd about all of this.

It's like someone raving about coffee picked by monkeys.

[Andy Schecter]

The Chemex habitually overextracts from the grounds near the bottom of the filter (and generally from the center, though that depends on your pouring method.) And the Chemex underextracts from those grounds at the periphery (those grounds that end up sticking to the filter high up the filter walls.)

Think about it: The grounds that stick to the filter high up its walls stop participating in the extraction process perhaps two minutes (or whatever) before the grounds at the bottom do.

Scott:

Have you read that book called "The Professional Baristas's Handbook?" Anyway, the guy seems to know what he's talking about. Here's a passage that he writes about espresso extractions, but it is quite relevant to any top-to-bottom extraction, including the Chemex:

...the upper layers of the coffee bed yield more solids than do the lower layers during extraction. Such uneven extraction is detrimental to flavor and brew strength: the upper layers overextract, yielding bitterness and astringency, and the lower layers underextract, resulting in less sweetness, less brew strength, and perhaps some underdeveloped flavors.

What's interesting about this passage is that the extraction pattern outlined in the book for espresso is the opposite of the extraction pattern you say that the Chemex produces.

Thinking about this, it seems possible that when a Chemex pot leaves the grounds near the top high and dry, it's a good thing: these grounds don't get overextracted as the upper layers might be in a typical espresso extraction.

In other words, it's possible that, if one works it just right, Chemex extractions can neatly compensate for the basic unevenness in top-to-bottom extractions. I imagine that "just right" involves the right pour volumes, pour timing, pour placement, grounds agitation, etc.

When people say they've had a great pot of Chemex coffee, undoubtedly they've brewed it in such a way as to make a good extraction happen. Maybe they don't know the theory behind it, but through experimentation they found a method that works well for a particular coffee. I have a hard time believing that it simply can't be done.

[Vince Piccolo]

Scott Rao says:

Chemex, like any brewing method, has the potential to extract the desired amount of mass from the grounds (let's say 20%) and to create a cup of the desired brew strength (let's say 1.4%). Some people really like the extreme amount of flavor clarity created by the thick Chemex filter, at the expense of the coffee's body, of course. Fair enough.

What no one seems to notice is that it is nearly impossible to extract that 20% EVENLY from the coffee bed. The Chemex habitually overextracts from the grounds near the bottom of the filter (and generally from the center, though that depends on your pouring method.) And the Chemex underextracts from those grounds at the periphery (those grounds that end up sticking to the filter high up the filter walls.)

Think about it: The grounds that stick to the filter high up its walls stop participating in the extraction process perhaps two minutes (or whatever) before the grounds at the bottom do.

Can anyone please discuss the above points and not make this about other personal issues and beliefs.

The point above is accurate in my experience and is the main reason I don't drink Chemex brewed coffee very often. The chemex is about creating a really great simple cup of coffee but it's not the best, easiest and most consistent way to achieve that goal. I don't see this discussion as anything more than what Scott has stated.

If Stephen Morissey has only had 6 great espresso's in his life, I can honestly say I've only had 2 good to great chemex prepared coffees. I believe there are better ways of brewing better and more consistent cups of coffee.

I'm still going to try and make some great coffee on a Chemex but I have a hard time recommending a chemex for a customer to brew at home and hope they can achieve anything near the quality they can get in our cafe.

I think we should all be a little less sensitive to valid discussions and point of views.

[Scott Rao]

Nick, two things and then I will flog myself for bothering to post here.

1. Your assumption that I am trying to market my plastic $20 gizmo is right on. Amazing that you picked up on it.

You have no idea how much I care about the general state of coffee preparation improving, even if it involves upsetting some people and being even less popular than I already am. And why is it relevant how frequently I post here?

2. If I was defensive, it was because I criticized Chemex and Peter in turn criticized me personally. There's a difference. Why in the world does anyone feel emotionally triggered by my criticizing a brewing method? Stop hiding behind "taste is all that matters" and start discussing the relative merits of various brewing methods and techniques, like a confident, non-threatened professional.

Does anyone actually want to discuss the merits of Chemex and various preparation methods? Can anyone do this without falling back on the cop out "I like it and taste is all that matters"?

I'd be thrilled if a Chemex-lover could share with me how they prepare it and why their method makes great coffee. I want to be totally wrong and to enjoy a Chemex immensely. Truly.

[Scott Rao]

Can anyone please discuss the above points and not make this about other personal issues and beliefs.

God bless you, Mr. Piccolo.

[xristrettox]

...just when i thought coffeed was going soft

I like the conversation. Makes me start thinking a little bit more about over/under extraction in espresso, and possibly existing at the same time, and correct definitions/causes for each.

but that's a different thread.

[Rich Westerfield]

Re: Taste is all that matters.

That's obviously true. It's also obviously a moving target, as James points out. In our case, we're five years smarter. And almost without exception, we enjoy what/how we're brewing today even better because developments for most brewing systems (mechanical or manual) have helped improve extractions and improved control and resulting flavor in obvious ways (taking into account we also have access to better coffees). And we know there are still improvements that can be made, whether in equipment, filters, technique or whatever.

I choose to think that's pretty much all that Scott is trying to say. Of everything we've brewed with, Chemex/pourover methodology has been the most resistant to change due to its design. Maybe it's time to think about how to improve it.

It got us thinking about using an Aeropress for applying water instead of a kettle (the diameter works for our #1 filters). The Aeropress cap is a showerhead and the plunger can be controlled to a small degree to apply bursts or a steady flow. Will be interesting if there are marked taste differences between wide dispersion vs. a controlled pour. I'd like to think someone's done this before for a cone filter pourover setup, but don't recall seeing anything on it.

I like the cleanliness of Chemex for many coffees, particularly later in the day. But we offer several brew on demand options in the shop because we don't believe one method represents all coffees or customers best.

As an aside, recently, I was tasting a bunch of coffees with arguably the best chef in Pittsburgh, helping him design a coffee program for his new restaurant. He was leaning to Chemex because of the design and ease of training/use (and cost) and he didn't like the clean up/grit of a press pot. But once we had winnowed down possibilities to a couple of coffees and then brewed same in Cafe Solos to compare against the Chemex, the chef was leaning toward Solos. "More masculine," he said.

So while there's no arguing that everyone here has tastebuds, the real question becomes, are you Chemex lovers girly-men

[David LaMont]

(completely avoiding all other arguments...)

I am interested to know more about what is going on inside the cone of a Chemex during the pour and how that compares to other comparable devices. In particular, I would love to see the way the coffee moved during the pour in a Chemex versus a Hario V60 AND how they moved given different pour methods. I'm honestly a little surprised that there have been so many mentions of stirring, not because I think it couldn't possibly benefit the coffee, but because I've never seen it done before. My understanding (whether right or wrong) is that the drip kettle provides all the agitation necessary.

We've been playing around with pour over a lot over the past few months, on Melitta, Beehouse, Chemex, and the Hario V60. The thing I love most about pour over is the ability to control the brew. If we pour quickly, trying to get all the water in as quickly as possible, then the resulting shape of the spent grounds is conical--clinging to the side of the filter evenly, all the way down the sides. It looks symmetrical, appealing, and "even". If we pour in doses (what I saw EVERY "master" at EVERY drip-based shop in Japan do) the resulting shape of the grounds can vary, to the point that there is no coffee on the sides of the filter, but rather a solid bed of spent coffee at the bottom. Its all in the pour (and pouring device?).

I definitely don't think that the environment inside the Chemex/V60 filter during the pour is a static one at all. Its probably waaaay more dynamic than the inside of an espresso basket. For example, at CCC Atlanta, we do all of our cuppings in 8oz clear gibraltar glasses, which are great for watching the motion of the coffee within the cup. When we pour the water, it isn't as if the coffee clings to the sides of the cup as if it were glued there. The coffee circulates rapidly as long as coffee is being poured. Same for the Chemex. We all know that the flow rate out of the filter isn't the same as the flow rate into the filter, so obviously the coffee is being moved around by the currents and flow of the water being poured in. So, I think that the exposure of the coffee to water is ALL about how you pour.

Last thought--I think we're getting hung up on the final drainage of the last drips of water through the coffee bed that resulted from our pour method. The Japanese shops I went into seemed to have a great solution for this. They MOVE THE FRIGGIN' FILTER. Just like I never saw a coffee shop operator pour a coffee in less than 3 additions of water (prewet, intial pour, final pour), I also NEVER saw a shop operator allow the water to drain completely from the filter into the customers cup. That's why all the Japanese pour-over devices come in 2 pieces--the filter and the receptacle. Hario does it. Melitta does it. Kalita does it. Chemex doesn't (gasp!!).

So here are my thoughts...

1. We should pour intentionally.
2. We should be using the right tools.
3. We should spend more time drinking and learning hand drip (and siphon for that matter) from the folks who have been doing it for a really really long time THEN innovate.

[Peter G]

Ok, I feel I have to clarify:

Scott, I have nothing but personal and professional respect for you as an author, coffee journeyman, and coffee thinker. Your resume is without equal as an innovator, entrepreneur and steward of great coffee. I did not intend to besmirch any of that. My little "on dogma" rant was about polarizing, antagonistic, and dogmatic language and positions in our industry, and how I feel it harms our progress. In other words, my beef was not with you, but with the tone of your post. Deep apologies if I failed to communicate that very well. Recently, you offered to buy me a beer. Now, I feel as if I owe you one.

But, as Vince said, this thread isn't about style, it's about the Chemex! My little dogma thing seems to have overshadowed the other points in my post, so I'll restate:

The main criticism of the Chemex here seems to have two parts:

1. The conical shape of the Chemex filter creates conditions that necessarily overextract the coffee in some palaces and underextract in others.

2. This range of different extractions always creates inferior coffee.

The first assertion, which seems intuitively true, needs proving in my view (many things that seem obviously true are not so simple). It seems that some think the top of the cone gets overextracted (perhaps due to hotter water, increased turbulence in this region, or the ability of "clean" water to absorb more solubles) others think the bottom of the cone overextracts (due to more water being forced through a smaller amount of coffee, or this region being in contact with water for a longer time). My personal feeling is that all of these have an effect, and that temperature, turbulence, gravity, particle size variance, time, and coffee type interact in complex ways that are difficult to quantify. Pouring styles, stirring regimens, etc. complicate an already complex environment. This complexity resists broad generalizations and cries out for thoughtful study and analysis. In my opinion, the reality is far more complex than the simple assertions we're making here!

Some specific things I have noticed: Good Chemex Brewers (Chemistas?) frequently use a style that leaves the spent grounds in a hollow cone, mimicing the interior hollow cone of the filter itself. I notice that if you were measure between the top of this coffee and the nearest paper-wall, the thickness would be close to 1-1.5", the "ideal bed depth" of the Golden Cup work. Interesting! It seems to me when I watch a Chemex brew, the liquid often pushes through the filter paper high up the sides, dripping down to the tip of the cone on the outside of that cone. It can't possibly be overextracting without any coffee grinds!!

It should be noted that the cone-filter was invented by Melitta Benz not because she thought the cone was the ideal shape for brewing coffee, but because it was easiest to get a piece of paper to form a cup shape by forming it into a cone (the same reason old-skool paper cups are cones) The Chemex is a cone simply because a piece of chemistry-set blotter paper easily folds into that shape. Flat-bottomed filter enthusiasts "fixed" that little thing by inventing the flat-bottomed filter. It's interesting that higher-end home brewers tend to stick with the cone-shape (Technivorm, Bodum Kona, Chemex, Melitta, Krups, etc.) where the low-end have adopted the flat-bottom (Mr. Coffee, Black and Decker, etc.) By the way- does the Chemex criticism also apply to Melitta style cones- including Technivorm?

All this reminds me of an article I recently read about Chinese cooking. The American author insisted that flat-bottomed American-style saute pans are better than woks for Chinese cooking, because the hot area is larger. I have no doubt the author has a point, but lots of Chinese cooks might disagree, and are making awesome food.

But I digress. All this stuff about varying extraction percentages aside, we still need to prove the second part of the assertion: that this kind of extraction is bad for coffee! In my mind it makes sense that a variety of extraction percentages (say, varying from 16 to 24%, the bulk being in the 19-20% range) might lend interest and complexity to the cup. The 18-22% figure of the Golden Cup is obviously an average, since it would be impossible to achieve this extraction perfectly among every single particle of coffee (since a fine particle would extract much more than a large particle) without a perfectly uniform grind. To me, this is where the interest is!

To me, the Chemex is indeed a tricky brew device. The 1-piece all glass design helps (I sometimes feel, perhaps illogically, that both stainless and plastic are bad for my coffee). It's an elegant, idiosyncratic brewer which I believe has earned its place among the classic coffee brewers. Can it be improved? Undoubtably. But man, I sure love the coffee bars that are using Chemexes and French Press and Melitta-style Drippers and Vacpots to brew their coffee- the coffeebar landscape is much richer for their presence.

Peter G

[David LaMont]

And for what its worth, there's something to be said for style. All science aside, If I came into a shop as an absolutely uninitiated customer and was presented with the choice between coffee prepared by hand for me in a hand-blown hourglass and a one prepared by giant steel box, I'd tend toward the glass. With a couple lights and some simple woodworking for a stand, a row of three chemexes has all the class and "awe factor" of a 3-top halogen vac bar, I think...and at a total cost of around $150! Cheap, beautiful, controllable...what's to hate?

[Aaron Ultimo]

I love this discussion.

[amber fox]

So while there's no arguing that everyone here has tastebuds, the real question becomes, are you Chemex lovers girly-men

i guess i am a "girly-man".
or maybe i'm just uppity.

anyway, in thinking about pourover brewing recently, i was wishing for a zero-gravity chamber, in which i could suspend the coffee particles for an immersion period, during which all particles would be evenly extracted. This would ideally finish with a quick flush through a fine cloth or pre-rinsed beached paper filter, with minimal further agitation (and potential for overextraction of some grounds that would receive more agitation than others).

NASA have any extra funding? maybe Google would be a better bet.