Chemex Metal Filter: Should You Ditch the Paper?
I was a dedicated Chemex paper filter user for about three years before I tried a metal filter. The switch changed the way my Chemex coffee tasted so dramatically that I now keep both types on hand and choose based on the beans I'm brewing. A metal filter doesn't replace paper filters for every situation, but it opens up a completely different flavor profile that's worth experiencing.
If you're curious about using a metal filter in your Chemex, this guide covers how they work, what they change about your coffee, the best options available, and how to decide between metal and paper for your daily brew.
How Metal Filters Differ from Chemex Paper Filters
Chemex's bonded paper filters are unusually thick compared to standard drip coffee filters. They're about 20-30% heavier than typical paper filters, and that extra thickness traps more coffee oils and fine particles during brewing. The result is a clean, bright, tea-like cup that Chemex is famous for.
Metal filters work on a completely different principle. Instead of absorbing and trapping, they use a fine mesh (usually laser-etched stainless steel) to separate grounds from liquid. The mesh holes are large enough to let coffee oils and very fine particles pass through into your cup.
This changes three things about your coffee:
Body. Metal-filtered Chemex coffee has significantly more body. It feels heavier and richer on your tongue. Paper-filtered Chemex is light and clean. Metal-filtered Chemex approaches French press territory for mouthfeel.
Oils. Coffee oils carry a lot of flavor compounds, including the ones that produce that buttery, round quality you taste in French press or espresso. Paper filters trap most of these oils. Metal filters let them through. If you've ever thought your Chemex coffee was too thin or missing some depth, a metal filter might be the answer.
Sediment. Even the best metal filters let some fine particles through. You'll notice a small amount of sediment at the bottom of your cup, similar to what you'd find in a French press, but usually less. This doesn't bother me at all, but some people strongly dislike any grit in their coffee.
Best Metal Filters for Chemex
Several companies make metal filters designed to fit the Chemex. I've tried three of them extensively.
Able Brewing Kone
The Able Kone is the original Chemex metal filter, and it's still the best. It's a cone-shaped stainless steel filter with a laser-etched hole pattern that fits perfectly into 6-cup and 8-cup Chemex brewers. The build quality is excellent, with a thick, rigid structure that won't flex or collapse during brewing.
The Kone produces a clean cup with good body and minimal sediment. The hole pattern is finer than most competitors, which means fewer fines in your cup. It retails for about $55-60, which sounds expensive until you factor in the cost of Chemex paper filters ($10-12 for a 100-pack) over the course of a year or two.
CoffeeSock Reusable Filter
The CoffeeSock is technically a cloth filter, not metal, but it fits the same niche. Made from organic cotton, it produces a cup somewhere between paper and metal for body and oil content. It's cheaper ($12-15) but requires more maintenance, since the cloth needs to be stored wet in the fridge between uses to prevent mold.
I used a CoffeeSock for about two months and liked the cup quality, but the storage requirements got old fast.
Generic Amazon Stainless Steel Filters
There are dozens of no-name stainless steel Chemex filters on Amazon for $10-20. Quality varies wildly. I bought three different ones to test. Two of them fit poorly (gaps between the filter and the Chemex wall let grounds bypass the mesh). One of them fit well and produced decent coffee, though with noticeably more sediment than the Able Kone.
If budget is tight, a generic filter can work, but inspect the fit carefully before committing to it as your daily driver.
For those considering upgrading their overall Chemex setup, our guide to the best coffee grinder for Chemex covers grinders that pair well with both paper and metal filters.
Grind Size Adjustments for Metal Filters
This is the part most people miss. You cannot use the same grind size for a metal filter that you use for Chemex paper filters. If you do, you'll get a cup that's muddy, over-extracted, and full of sediment.
Go Coarser
Metal filters need a coarser grind than paper filters. With paper, I grind at a medium-fine setting (about 20 on a Baratza Encore, or roughly the consistency of table salt). With a metal filter, I bump it up to medium or even medium-coarse (about 24-26 on the Encore, closer to coarse sand).
The reason is flow rate. Paper filters slow down the water significantly because the paper itself acts as a barrier. Metal mesh offers very little flow resistance. If you use a fine grind with a metal filter, the water rushes through too quickly, under-extracting the coffee. Going coarser slows the effective contact time and produces a balanced cup.
Adjust by Taste
Start at medium-coarse and brew. If the coffee tastes sour, weak, or thin, grind one click finer. If it tastes bitter, harsh, or astringent, grind one click coarser. Two or three brews should get you dialed in for a particular bean.
I keep notes on my phone with grind settings for different filters and beans. It takes 30 seconds to jot down and saves me from re-dialing every time I switch.
Metal vs. Paper: When to Use Each
After using both for over a year, here's my personal decision framework.
Use Metal When:
- Brewing dark or medium roasts where body and richness are the goal
- Brewing beans with chocolate, caramel, or nutty flavor notes
- You want something closer to French press flavor with Chemex convenience
- You're tired of buying paper filters
Use Paper When:
- Brewing light roasts with delicate floral or fruity notes you want to preserve
- You prefer an extremely clean, sediment-free cup
- Brewing for guests who might be put off by any grit in their coffee
- You want the classic Chemex flavor profile
There's no wrong answer here. It really comes down to what you enjoy drinking. Some weeks I use metal every day. Other weeks I'm on a light roast kick and use paper exclusively.
Cleaning and Maintaining Your Metal Filter
Metal filters are easy to maintain, but they do need regular cleaning to prevent oil buildup that affects flavor.
After Every Use
Dump the used grounds (they compost well). Rinse the filter under hot running water, rubbing gently with your fingers to clear the mesh. Hold it up to a light, and you should see clear, open holes across the entire surface. If any areas look clogged, give them extra attention.
Weekly Deep Clean
Soak the filter in a solution of hot water and a teaspoon of baking soda for 15-20 minutes. This dissolves coffee oils that rinse water alone won't remove. After soaking, scrub gently with a soft brush (an old toothbrush works) and rinse thoroughly.
Some people use dish soap for daily cleaning. I avoid it because soap residue can linger in the mesh and affect coffee flavor. Hot water and occasional baking soda soaks keep my filter clean without any off-flavors.
Lifespan
A quality metal filter like the Able Kone should last 3-5 years or more with proper care. The mesh doesn't wear out from normal use. The main risk is physical damage from dropping or bending. Store it carefully, and it'll serve you for a long time.
Compare that to paper filters at roughly $30-40 per year for daily Chemex use, and the metal filter pays for itself within 18 months.
FAQ
Does a metal filter change the caffeine content of Chemex coffee?
Not significantly. Caffeine is water-soluble and passes through both paper and metal filters equally. The oils and fine particles that metal filters let through contain minimal additional caffeine. The difference in caffeine between metal-filtered and paper-filtered Chemex is negligible.
Will a metal filter fit my Chemex size?
Most metal filters are designed for the 6-cup and 8-cup classic Chemex models. If you have a 3-cup Chemex, check the product dimensions carefully, as some filters are too large. The Able Kone specifically fits 6-cup and larger models.
Can I use a metal filter with the Chemex Ottomatic?
Yes. The Chemex Ottomatic automatic brewer accepts both paper and metal cone filters. Just adjust your grind coarser when switching to metal, since the Ottomatic doesn't automatically compensate for the different flow rate.
Is metal-filtered coffee less healthy than paper-filtered?
Paper filters trap cafestol and kahweol, two compounds in coffee oils that can raise LDL cholesterol levels. Metal filters let these compounds pass through, similar to French press coffee. For most healthy adults, the amount of cafestol in a few daily cups of unfiltered coffee isn't a significant health concern. But if your doctor has specifically told you to watch your cholesterol, paper filters are the safer choice.
Check out our best coffee grinder guide if you're looking for a grinder that can handle the coarser settings metal Chemex brewing requires.
Pick the Filter That Fits Your Flavor Preference
A Chemex metal filter is worth trying if you've ever wished your pour over had more body, more richness, or more of that rounded, oily quality you get from immersion brewing. Start with the Able Kone if budget allows, or grab a well-reviewed Amazon option for under $20. Grind coarser than you would for paper, and give yourself three or four brews to dial it in. You might end up using both, like I do, and that's the best of both worlds.