Chemex Coffee Brewing Guide - Background and Tutorial

This is one of those oldie-but-a-goodie moments. While a Chemex may look modern, you’ll find this relic in museums. It had its humble beginnings in 1941, where this pour-over method stole away high-brow coffee drinkers from the endlessly-popular percolator.

Peter J. Schlumbohm is the creator of the Chemex, and I think there was a massive lost opportunity here — I mean, Schlumbohm. Don’t most people name their inventions after themselves?

Without further ado, here's our Chemex Brewing Guide, featuring background information and an easy-to-follow tutorial.

Background

Like I said, it was created by Peter J. Schlumbohm, a man who doesn’t know how to name things, but apparently has 3,000 patents under his belt. I don’t even want to know what he named all of the other 2,999 things.

Back to the Chemex, though. This not-so-modern marvel is actually the combination of two rather unlikely objects: a laboratory glass funnel and Schlumbohm’s Erlenmeyer flask. Before you start crafting some sort of alcoholic background for Schlumbohm, an Erlenmeyer flask has nothing to do with gin, whiskey, or vodka. It’s actually what we iconically think of as laboratory equipment. Dude who named that clearly had as many issues as our German Chemex-maker.

Schlumbohm combined these two pieces of equipment using a wooden handle and ta-da—the next coffee craze.

Currently, Chemex is owned by Adams Grassy. It was purchased by his father in 1980, and the family still runs it today. They’ve maintained the same classic look it started with — a wooden collar with a neatly-tied leather belt — and they’ve kept the same down-home way of doing things in the small, Pittsburgh-located factory. They still hand-tie those leather cords, if you’re curious.

Don’t get me wrong, Grassy has rebranded, brought back some vintage hand-blown items, and even offers various colored rawhide ties to cinch the waist of your Chemex with. You can get Chemexes with just enough space for one cup of coffee or thirteen, because, hey, who doesn’t like to impress friends of friends of friends?

They sell merchandise, like t-shirts, so you can be a walking billboard for your favorite morning mood enhancer, and you can even make a customized Chemex with fancy engravings on the collars or prints on the glass.

Chemex may only really offer one item, but they’ve found pretty enticing ways for their demographic to show the love (in the form of cash) (what else?).

What Makes It Different?

Great question! Well, for starters, it’s a single unit, which is always nice. Many pour-over methods settle on top of your own mug or carafe, so that’s an extra thing you have to make sure is clean. I don’t know about you, but I have a limited capacity in the A.M., especially when it comes to household chores.

Chemexes also use a special filter that’s as much as 30% thicker than typical filters. If you’re wondering, “why is that desirable?” then let me just say, goodness, you ask all of the best questions.

It’s desirable because it results in a clean cup of coffee — the filters are designed to let the taste and the deliciousness through the fibers, but not those pesky grounds. Even finely ground coffee doesn’t stand a chance against these tightly woven fibers, which are layered three deep at the apex.

Chemexes are made of borosilicate glass. Borosilicate being the key word here. You may be aware that glass can be sensitive to extreme heat or cold, which would be bad for our little coffee adventure here.

Like most other glass carafes, Chemex glass is made from silica and boron trioxide — this combination makes for very low coefficients of thermal expansion. In non-sciency terms, it won’t crack or explode when coming in contact with a lot of heat. Perfect, right?

Chemexes also have a built-in pouring spout, making transferring the magic bean juice from this device to your mug easy enough for even a drowsy mind, also perfect. 

Chemex vs. French Press vs. Any Other Pour-Over Device

chemex vs french press vs pourover

When we’re talking about more involved coffee methods, it really comes down to preference, but let’s discuss the differences so you can make an informed decision.

Chemexes result in a clean-tasting, bright cup of coffee using the filter (or drip) process. It is more fussy than alternate methods of coffee making and can take a few minutes longer, so it does come down to how well you take to it and how much time you allot for your coffee needs in the morning.

French presses are simple and quick since they take advantage of steeping. Rich, aromatic, and full-bodied, using a French press gives you the full experience, including the oils that Chemexes filter out. The total time from device to mug is shorter, but taking the last sip of this brew can result in a mouth of sediment that will ruin the entire morning.

When it comes to pour-over methods, there are a few ways to tell what’s in your cup. Chemexes use bonded filters, which result in a taste that’s identifiably Chemex. There’s no way around it. They proudly claim no bitterness and no sediment, no matter how strong your drink your jet fuel, which certainly has its bonuses.

Again, though, it all comes down to how your snowflake taste buds feel, but the Chemex certainly ranks high on the ultimate-ways-to-make-coffee list. 

Sold. So, Tell Me What I Need.

You got it.

Alright, so, you need a Chemex, obviously. You’ll need the filters that go along with the device, that’s pretty key. Those are the two big-ticket items, but there are also several other things that will assist in creating the perfect cuppa joe. 

  • Timer
  • Kitchen Scale
  • Pour-over kettle
  • Thermometer
  • Conical burr grinder
  • Freshly-roasted whole coffee beans

We’ll tackle the list from the bottom up.

Freshly-Roasted Whole Coffee Beans

If you showed up to this tutorial bearing a bag of pre-ground nonsense, you turn you butt around and head back to your local roaster (or grocery store). We’re doing this right.

Here’s why: the moment beans are roasted, they become a perishable item. Yes, coffee can go stale.

We asked our friend Willem Boot, Founder & CEO of Boot Coffee, about how long coffee beans last. He had this to say: "I don’t recommend anyone to age ground coffee longer than one week. Already during that time frame, the coffee will loose quality significantly."

You may read something online stating that coffee can last anywhere from 3-5 months (or longer), but Willem feels that beans are good for a maximum of three weeks, "assuming the coffee is stored airtight and away from moisture, heat, and light."

Willem added, "Brewing coffee with five-month-old grounds will color your water brown and possibly make you nauseous or worse!"

So you heard it here, folks. Keep it as fresh as possible.

If you’re really not sure what type of roast you’ll like best, you can take a look at this guide right here (written by yours truly) to help make your decision.

Conical Burr Grinder

Whether you're brewing with a Chemex or any other type of brewing system, we strongly recommend using a conical burr grinder instead of a blade grinder.

The simple fact is this: a blade grinder works harder, not smarter. It spins incredibly fast and chops up the beans in a rather mad fervor. All of this frantic, quick movement creates exactly what we don’t want: heat and choppy grounds. Blade grinders pre-cook your beans, which can lead to your mid-afternoon mug boasting a burnt taste.

Conical burr grinders work differently. They use either ceramic or stainless steel burrs, move more slowly than a blade grinder, and, as a result, produce much neater work. They don’t create excess heat and they produce a consistent, even ground that’s far better for brewing with.

Inconsistent grounds can lead to a cup that’s both over- and under-extracted due to the multi-sized grounds. That’s a nightmare you want to avoid! If you want to read about this more in-depth, check out our coffee grinder article.

Pour-Over Kettle

I mean, we all want to look chic, right? Pour-over kettles are both classic and functional. They allow you to evenly distribute the heated water across the grounds. And that old-timey lengthy spout makes for a great Insta-pic.

Sue me for being a millennial. I like when things pull double duty.

Just how I like when my pour-over kettles come with a built-in thermometer. Double duty. It’s a beautiful thing. You can opt for a separate thermometer, as well, if you just like having a lot of fancy gadgets and gizmos. 

Kitchen Scale

This doo-dad is optional, but very helpful. You need to create the perfect balance between coffee grounds and water, and measuring is (obviously) the most precise way to handle that little problem.

Timer

The microwave timer can handle this job just fine, but no matter what you choose, you’ll want something keeping track of how long you’re pouring over and then how long it takes to finish dripping. This is a pretty important piece of the puzzle when it comes to troubleshooting, so just keep an eye on the time.

What Is This Filter Thing?

Chemex filters come in four different shapes. Pre-folded circles, pre-folded squares, pre-folded squares (natural), and unfolded half moon.

This is probably the least enticing part of using a Chemex for your morning brew. Some of these filters don’t fit certain versions of this pour-over device, so please be aware of which one you own before purchasing.

The half-moon filters are primarily for the pint-sized Chemexes, so keep that in mind. They do all cost the same, so you don’t have to worry about doling out more cash if you opt for a larger Chemex. They’re sold 100 per box, which isn’t a bad amount — it’ll get you through three months with a pot a day.

They provide instructions for folding traditional filters right here on the Chemex website, but… ya know. The pre-folded square filters you basically just open and drop in. I vote for that route.

Okay. I think we’ve got it all sorted out now that you know what you need and why. It’s finally time to get to the meat and potatoes of what we’re here to do: learn how to use the Chemex, step-by-ever-loving-step. 

Here We Go—Step-By-Step

We’ll take this nice and slow. If you take your time and really cross your t’s and dot your i’s the first we times you use the Chemex, it’ll become second nature as you go along. That being said, let’s get started!

1

The first matter of business is setting everything up. Unfold the pre-folded square coffee filter and settle it inside the Chemex. Make sure that the section of the filter with three layers goes over the pouring spout of the Chemex. The opposite side should boast just one layer. 

2

Boil the water in your pour-over kettle. If it has a built-in thermometer, you can rely on that to reach the necessary temperature, between 195-205 degrees Fahrenheit. If not, you’ll need to have a separate thermometer to check it. 

If you don’t have a way to confirm the degrees with any level of accuracy, you can do a very rough estimate. Keep in mind, I don’t recommend this, but it works in a pinch. Let the water come to a boil and then remove from the heat. Wait roughly 40 seconds and it should be about where it needs to be.

3

While the water is heating up, let’s attend to the grounds. Open your bag of whole beans and load them into your conical burr grinder. Chemexes work best with a medium-to-coarse grind, but we recommend starting off with a coarser setting  and moving to a finer grind if necessary.

As to the amount of grounds, we recommend starting with 35 grams of coffee and using a 1:15 coffee-to-water ratio. That's 1 gram of coffee for every 15 grams of water (which equals 525 grams of water, in this case). You can always adjust the ratio to your preferred flavor profile and to the coffee that you're brewing.

4

Alright, once you have your grounds ready to go, leave them in the grinder. Grab the slowly heating water and pour some through the Chemex empty filter. This is called pre-wetting, and it gets rid of any taste from the paper that could influence what ends up in your mug.

As a bonus, it also heats up the Chemex a bit, readying it for the headliner of this show: the brew. Discard this water and let’s get on to the main event!

5

Layer the grounds inside the filter and give the Chemex a little bit of a shake to even them out, creating a nice, flat surface. This is where the kitchen scale comes in handy — slide it right underneath the Chemex and zero it out. 

6

Start your timer. Then, pour in just enough water to saturate the grounds. (Remember: the water temperature should be between 195-205 degrees Fahrenheit.)


Wait for this small amount of water to filter completely through, and then give the grounds a quick (but gentle) stir to make sure there aren't any clumps in the grounds. 


Now PAUSE. Wait 30 seconds (This is called the 'blooming' process).


7

In a slow and circular motion, begin pouring the water until it nears about one inch from the top of the Chemex filter. Allow the water level to lower, and then, using the kitchen scale as your guide, pour the remainder of the 525 grams of water you started with. All of the water should be even distributed across the top of the grounds within 3-5 minutes.


Note: You should never overfill the Chemex filter — always leave at least an inch between the top of the device and the water level.

Once the water’s all been poured, wait for all of the coffee to finish draining into the Chemex. And that's it! Time to enjoy.

Troubleshooting

Scenario #1

You: It’s been like… 15 minutes and the thing’s still dripping.

Me: Woof. Yeah, alright. Easy-peasy. Make sure you’re pre-wetting and letting the grounds bloom. If you’re doing that, then the grind is too fine. The water can’t make it through all of those little particles. If it’s taking literally 15 minutes, then you should up the grind size several notches. If you’re being a tad dramatic in your desperate need for coffee, take it up a size or two and see if that makes a difference. 

Scenario #2

You: My “coffee” tastes like dirty water.

Me: What did you do, drop whole beans in there? If you did, in fact, grind them up, there’s really only one other thing that causes that: not-hot-enough water. Are you eyeballing it? Bet you are. Get a thermometer. It has to be between 195-205 degrees Fahrenheit.

You: You said if I waited 40 seconds after boiling it would—

Me: I guaranteed nothing, good sir. Now stop being cheap and buy a damn thermometer.

Scenario #3

You: The filter doesn’t fit. I swear I’m doing it right. 

Me: In my magic crystal ball, I can see that you’re using the half-moon filters, and I can also see that you’re not making sharp enough creases. 

You: How did you know I was using the half-moon ones?!?

Me: A magic. Crystal. Ball. I told you! ...also, they’re the only ones that don’t come pre-folded. 

You: Oh. 

Me: Yeah. 

In Conclusion

Chemexes have nearly 80 years of usage under their belt, and they’re remained largely unchanged since they were created. It’s one of the few, the fair, the totally functional things that’s better left untampered with.

It is fussy and it does take some practice to get just right, but the results are incomparable: a cup of the good stuff that’s as strong as you want it without a trace of bitterness and not a single errant grind to boot. It’s certainly worth giving a shot, especially since you can Prime 2-day most of the equipment.

If you prefer more automatic methods, you can opt for the Ottomatic (get it?!), which is also made by Chemex. Reviews are a bit up and down, but, hey, all in the name of ease, right?

Final word on the matter: Chemexes are definitely worth allotting the time in the morning. As someone who loves sleep and is always tapping that snooze button for more, I don’t say this lightly. Now, off with you! Enjoy your “clean” cup of joe! 

how-to-make-chemex-coffee

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About the Author Rachel Bean

Hi! My name is Rachel Bean and I love coffee. Despite what it may seem like, my last name and deep love for a cup of black brew is a total coincidence. While I was informed at the wee age of 18 that majoring in coffee wasn't really an option (at least not the way I wanted to major in coffee) (i.e. drinking it day in and day out), I do have an MA and an MFA in Writing. I type words day in and day out, for both work as well as fun, and coffee is the magic bean juice that lets me do that. And that's pretty much me. Writing and coffee. Oh, and rescue dogs. Writing, coffee, and dogs. You get me.

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