Best Grind Size for Chemex
The best grind size for Chemex is medium-coarse — distinctly coarser than V60 or Kalita, somewhere between coarse sand and granulated sugar. The Chemex uses bonded paper filters that are roughly three times thicker than standard pour-over papers, so they drain more slowly and a finer grind will clog them entirely. Get the grind right and a Chemex produces some of the cleanest, brightest coffee you can brew at home.
This guide explains why Chemex grind is coarser than V60, what medium-coarse actually looks like, and how to adjust when your Chemex won't drain or finishes too fast.
Why Chemex Needs a Coarser Grind Than V60
Two things make the Chemex unique: the thick bonded filters and the carafe-style geometry. The filters trap more fines and oils than thin pour-over papers, which is what produces the famously clean cup — but the trade-off is restricted flow. Use a V60 grind in a Chemex and you'll watch a puddle sit on top of the bed while drawdown drags past five minutes.
A coarser grind compensates. Bigger particles create more space between them for water to flow through the bed and out through the thick paper. The result is a brew that drains in a reasonable 4:00–5:30 (the standard window for a full Chemex) while still extracting evenly.
What Medium-Coarse Looks Like
Picture coarse sand or coarse sugar. Distinct, separate grains. Slightly larger than the medium grind you'd use for an auto-drip machine, noticeably coarser than V60 (fine sea salt). When you rub it between your fingers it should feel gritty, not powdery.
If you have a burr grinder, common starting points:
- Comandante C40 — clicks 28–34
- Baratza Encore — settings 20–25
- 1Zpresso JX — clicks 90–105
- Fellow Ode Gen 2 — settings 7–9
These are starting points. Adjust based on what's in the cup.
How to Dial In Chemex Grind
Brew at a 1:16 ratio with your grinder's medium-coarse setting — for a typical 6-cup Chemex that's around 42g of coffee to 670g of water. Time the brew from first pour to last drop.
- Target drawdown: 4:00 to 5:30 for a full 6-cup brew. Smaller batches (1–2 cups) finish faster, around 3:30–4:30.
- Too fast (under 3:30): under-extracting. Tighten the grinder one or two clicks.
- Too slow (over 6:00): filter clogged with fines. Coarsen the grinder. If the bed still won't drain, your grinder is producing too many fines — see our piece on grinder particle distribution.
Adjust grind in single-click increments and brew the same recipe twice before changing anything else.
How Roast Level Shifts Chemex Grind
The Chemex performs best with medium and lighter roasts because the clean, filter-stripped profile suits brighter, more delicate coffees. Dark roasts can taste hollow in a Chemex unless you grind tighter to compensate.
- Light roast: one or two clicks finer than your default, plus higher water temperature (95–96°C / 203–205°F).
- Medium roast: default setting.
- Dark roast: marginally coarser, lower water temperature (90–92°C / 194–198°F).
The Chemex's clarity-first character makes it especially well-suited to washed Ethiopians and Kenyan AAs — the kind of coffees that show off when nothing's covering them up.
Common Mistakes
- Using V60 grind by default. Easily the most common Chemex mistake. The cup will be over-extracted, the drawdown slow, and the filter clogged with fines.
- Skimping on the bloom. Bloom for 30–45 seconds with twice the coffee weight in water. CO₂ release matters in a Chemex too.
- Not rinsing the filter. Chemex papers are thick and bring noticeable papery flavor if not rinsed thoroughly with hot water before brewing.
- Pouring on the spout side. Chemex filters fold so one side has three layers, the other has one. Always pour with the three-layer side facing the spout — this stops the filter from collapsing during brewing.
For broader context on how Chemex filter design shapes extraction, Perfect Daily Grind's comparison of home brewing methods puts the Chemex in perspective against other filter brewers.
Frequently Asked Questions
What grind size for Chemex?
Medium-coarse, like coarse sand or coarse sugar. Distinctly coarser than V60 because Chemex filters are thicker and drain more slowly. Target drawdown is 4:00–5:30 for a full 6-cup brew.
Why does my Chemex take forever to drain?
Either your grind is too fine, or your grinder is producing excessive fines that clog the thick paper. Coarsen the grinder one or two clicks first. If the problem persists, the fines are the culprit.
Can I use the same grind for Chemex and V60?
No. V60 wants medium-fine (fine sea salt), Chemex wants medium-coarse (coarse sand). Using V60 grind in a Chemex will clog the filter and over-extract the coffee.
Does Chemex grind change for the 3-cup vs 6-cup brewer?
Slightly. The 3-cup Chemex has a smaller bed and drains marginally faster, so you can go a click finer if you want. The 6-cup is the workhorse and benefits from a touch more coarseness to keep drawdown in range.
Coffee Built for Filter Brewing
Chemex strips out fines, oils, and noise — what's left is a transparent view of whatever's actually in the bean. That's punishing for stale or unremarkable coffee and rewarding for fresh, well-roasted specialty.
Good technique deserves good coffee. Podium Coffee Club ships beans from US roasters who've placed at the major competitions — judged blind, sent within 24 hours of roasting. Gold is $24.50/month, Platinum is $29.50/month. Both 300g whole bean. The full best coffee subscriptions guide is here if you want the wider context.
