How to Clean Your Chemex Properly (the 5-Minute Version)
If you've been putting off cleaning your Chemex because it seems fussy — the glass, the wood collar, the spout, the filter residue — this is the post that makes it simple.
We clean ours every time we use it, and the whole thing takes about 5 minutes from start to "ready for the next brew." The secret isn't effort. It's the right soap, the right brush, and knowing which shortcuts actually work (and which ones will ruin the brewer).
This is the maintenance companion to our French press vs pour-over vs Chemex comparison. Same brewer, different angle. That post was about why you'd choose a Chemex. This one is about keeping the one you have actually working.
Why cleaning matters more than you'd think
A Chemex is a thick glass carafe with a paper filter. The paper filter catches most of the coffee oils and fines that would otherwise end up in the cup. But it doesn't catch everything. Over time, oils accumulate on the inside of the carafe, around the spout, and in the groove where the filter sits.
If you don't clean it:
- The carafe gets cloudy. Coffee oils build up in a thin film that makes the clear glass look dull. You can still brew through it, but it's not pretty, and it can start to affect flavor.
- The pour spout gets slow. Oils and fine sediment can build up around the pour spout, narrowing the opening. Pour speed drops, and you end up with coffee that over-extracts during the slower pour.
- Old coffee oils go rancid. This is the part most people don't realize. Coffee oils oxidize over time. Rancid oils in your brewer make the next cup taste stale, even if the coffee itself is fresh. If your Chemex coffee has started tasting "off" and you can't figure out why, it's probably the brewer.
The fix is 5 minutes after every brew. Here's the routine.
What you need
Three things, all of which you probably already have:
- Unscented dish soap. The unscented part matters. Scented dish soap leaves a residue that affects the taste of the next brew. We use Seventh Generation Free & Clear or similar. If you don't have unscented, dilute whatever you have heavily and rinse very thoroughly.
- A bottle brush. The kind with soft bristles on a flexible wand. Specifically designed for narrow-neck bottles. You can buy one for $3-5 at any kitchen store or Target. The brush needs to fit through the top opening of the Chemex (about 2.5 inches for the 6-cup) and reach down to the spout at the bottom.
- Hot water. From the tap is fine.
Optional but recommended:
- Baking soda. For the deep clean (once a month or so). Removes any lingering odors or stains.
- A soft microfiber cloth. For drying and polishing the outside.
What you do NOT need: bleach, vinegar (controversial — more on this below), the dishwasher, or any commercial coffee equipment cleaner. All of those either don't help or actively make things worse.
The 5-minute cleaning routine (after every brew)
Step 1: Dump the grounds and rinse (30 seconds)
As soon as you've poured the last cup, take the Chemex to the sink. Pull out the filter with the grounds inside (compost the grounds or knock them into the trash). Rinse the carafe with hot water to remove loose grounds and most of the surface oils.
Step 2: Add soap and hot water (30 seconds)
Add a small amount of unscented dish soap — about a teaspoon — and fill the carafe about a third full with hot tap water. The soap concentration should be enough to make the water slightly slippery when you swish it.
Step 3: Brush the inside (2 minutes)
Insert the bottle brush through the top opening. Scrub the inside of the carafe in slow circles, working from the bottom of the brewing chamber up to the rim. Pay attention to:
- The spout. This is the most important part. Coffee oils build up around the pour spout and gradually narrow the opening. Get the brush down to the spout and scrub in slow circles. If the brush doesn't fit, use a chopstick or thin skewer wrapped in a small piece of soft cloth.
- The groove where the filter sits. This is the indentation in the carafe where the paper filter hangs. Oils accumulate here and slowly drip into future coffees. Scrub along the groove.
- The sides of the carafe. General scrub. The bottle brush handles this.
Step 4: Rinse thoroughly (1 minute)
Empty the soapy water. Rinse under hot running water for at least 30 seconds. Make sure all soap residue is gone — any remaining soap will affect the taste of the next brew.
To check, rub your finger on the inside of the carafe after rinsing. If it feels slippery at all, rinse more. If it feels like clean glass, you're good.
Step 5: Dry upside down (30 seconds active, 5 minutes passive)
Place the Chemex upside down on a drying rack or a clean dish towel. The wood collar (if you have one) can stay on — it's designed to handle water. The carafe will air dry in 5–10 minutes.
You can also dry it by hand with a soft microfiber cloth if you're brewing again immediately. Don't use a paper towel — it can leave fibers on the glass.
That's it. Total time: about 5 minutes. Most of that is passive drying.
The deep clean (once a month)
Once a month, give the Chemex a more thorough cleaning:
- Baking soda paste. Mix baking soda with a small amount of water to form a paste. Apply it to the inside of the carafe and let it sit for 10 minutes.
- Scrub and rinse. Scrub with the bottle brush and rinse thoroughly.
- Check the wood collar. If the wood collar has any coffee stains, wipe it with a damp cloth and a tiny bit of the baking soda paste. Don't soak the wood — it can swell.
- Air dry.
The deep clean removes any lingering cloudiness and any odors that have built up. If you brew daily, monthly is right. If you brew weekly, quarterly is fine.
What NOT to do (the mistakes that shorten a Chemex's life)
Don't put it in the dishwasher
The high heat and aggressive detergent can crack the glass and damage the wood collar. Even if your Chemex survives, the dishwasher detergent leaves a residue that's nearly impossible to fully rinse out of the glass. The next brew will taste like dish soap.
Hand washing only. It's not that hard.
Don't use bleach
Bleach doesn't help with coffee oils (it doesn't cut grease well) and it's nearly impossible to fully rinse out of glass. Residual bleach in a brewing carafe is a health concern and will absolutely affect the taste of future brews.
If you want to sanitize (rare, and only if you're storing the carafe for a long time), use a dilute vinegar rinse followed by very thorough water rinsing. We rarely bother.
Don't use steel wool or abrasive scrubbers
The Chemex glass is borosilicate, which is tougher than most glass but can still scratch. Abrasive scrubbers leave micro-scratches that become sites for oil buildup over time. Soft brush or soft sponge only.
Don't leave wet grounds sitting in it
The coffee oils from the spent grounds continue to leach into the carafe while they sit. If you brew a pot and forget to clean it until the next morning, the carafe has been marinating in coffee oil for 12+ hours. Get to it within an hour or two of brewing for best results.
What about the wood collar?
The wood collar is held on with a simple tie (usually leather). You can leave the collar on while washing — the wood is treated and handles water fine. Just don't soak it for hours or leave it submerged.
If the wood starts to dry out or crack over time (after years of use), you can rub it with a tiny amount of food-safe mineral oil. Don't use cooking oils — they go rancid.
How to tell when the brewer is actually clean
A clean Chemex looks like glass. It should be transparent, not cloudy. The pour spout should be the same width it was when you bought it. If you hold it up to a light, you shouldn't see any film on the glass.
If you brew a cup of plain water through the cleaned Chemex (no coffee, just a rinsed filter and water), the water should taste like nothing. If it tastes like soap, old coffee, or anything else, rinse more.
How to store it when you're not brewing
If you're storing the Chemex for more than a few days:
- Clean it thoroughly first. Per the routine above, plus the monthly deep clean.
- Let it air dry completely. Any moisture trapped in the carafe can cause mildew or mineral deposits.
- Store it somewhere dry and stable. Not the edge of a counter where it might get knocked. Not a cabinet where it might get bumped every time you open the door.
If you're storing it for months, put a small piece of clean paper towel inside to absorb any residual moisture. Replace the paper towel every month or so.
What we do at the roastery
We have three Chemex brewers at the roastery (a 3-cup, a 6-cup, and an 8-cup). We use all three regularly. The cleaning routine is the same as what we just walked through — soap, brush, rinse, dry.
The 5-minute investment per brew is part of the cost of using the method. We don't think of it as a chore. We think of it as part of the brewing ritual — the part that happens after the cup is poured.
If you've been skipping the cleaning because it seemed fussy or because the Chemex looked OK, give the routine a try. The first time you brew through a freshly cleaned Chemex, you'll notice the cup is brighter and the spout pours faster. That alone is worth the time.
For more on the Chemex and how it compares to other methods, the French press vs pour-over vs Chemex post walks through the tradeoffs. And if you're picking a coffee to brew in your freshly cleaned Chemex, our Costa Rica is the brightest, cleanest cup in our lineup — the one that benefits most from a sparkling clean brewer.
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The point of this post isn't to sell you cleaning supplies. You already have what you need. The point is the 5 minutes. Cleaning the brewer isn't optional maintenance — it's part of using it well. If you're going to invest in the Chemex and the coffee, give it the rinse. Every bag you buy helps fund animal rescue efforts through our partnership with ASPCA, Best Friends Animal Society, and local shelters.
Brew slow. Sip slow. ☕
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P.S. If your Chemex has built up a stubborn cloud that won't come off with soap and water, try a paste of baking soda and water applied with a soft cloth. Let it sit for 10 minutes, scrub gently, rinse thoroughly. That usually does what regular soap can't. If the cloud is permanent (usually from years of mineral deposits in hard water), it might be time for a new Chemex — they start around $45 for a 6-cup.