Comandante C40 grind settings.
The reference hand grinder for filter coffee, and the dial most community charts are written against.
The chart
Starting points, not targets. Each number carries a ± 1-click band because that is the honest resolution of this dial — land inside the band, then let taste move you.
| Brew method | C40 clicks |
|---|---|
| Espresso anchor | 10 ± 1 |
| Moka pot | 13 ± 1 |
| AeroPress (short, fine) | 15 ± 1 |
| V60 / pour-over | 18 ± 1 |
| Kalita Wave | 20 ± 1 |
| Chemex / batch drip | 22 ± 1 |
| Clever / switch immersion | 25 ± 1 |
| French press anchor | 32 ± 1 |
| Cold brew | 35 ± 1 |
One click on this grinder moves the grind by about 0.30 of a point on the 1–10 universal scale — so roughly 2 clicks is the smallest change worth making between brews.
A chart gets you a starting number and then stops. Coffee Aeye quotes every recipe in C40 clicks to begin with — and when you rate the brew, it tells you which way to move and how many, on this dial.
€4.29 on Google PlayWhere these numbers come from
Two anchors, and interpolation between them. Espresso and French press are the only two bands that manufacturers and community charts actually document with any consistency, so those are the fixed points: espresso at 10 and French press at 32. Everything between is a straight line drawn through them, quantised to the click this dial actually resolves.
Absolute accuracy is not possible and this page will not claim it. Burr wear, per-unit zero points and assembly tolerances all shift where a number lands. What the two-anchor method gives you is the right shape — correct spacing between methods, correct direction of travel — which is what you need to dial in efficiently. The rest comes from calibration.
How this grinder works
The adjustment knob sits under the burr assembly. Zero is burr contact — turn it fully closed until the burrs just touch, then count clicks outward. Every number on this page is a count from that closed position, so a C40 that has been reassembled needs re-zeroing before the chart means anything.
Calibrating the chart to your own C40
If the chart runs consistently coarse or fine for you, do not nudge every row. Re-anchor it:
- Find your espresso mark — the click where a 1:2 shot in about 28 seconds actually happens on your machine. If you do not pull espresso, use the finest point where a moka pot does not choke.
- Find your French press mark — coarse enough that a four-minute steep is clean rather than muddy, and the plunger does not fight you.
- Enter both in Coffee Aeye. Replacing the two anchors corrects the zero point and the slope at once, and every method in between re-derives from your own two numbers.
This matters more on some grinders than others — it matters most anywhere the dial is stepless or the zero is set by hand.
Known quirks of the C40
The Red Clix accessory changes every number on this page.
The RX35 axle roughly halves the size of one click, so the same grind lands at roughly double the click count. If you run Red Clix, do not use the table above — calibrate your own two anchors instead and the whole chart rescales itself.
It does not really do espresso.
The chart puts espresso around 10 clicks and it will physically get there, but the C40 is a filter grinder with filter burr geometry. Treat anything under about 12 as a moka-pot floor rather than a genuine espresso range.
Click feel degrades before grind quality does.
The detents soften with heavy use long before the burrs dull. If clicks start feeling vague, count carefully rather than by touch.
Moving the dial when a brew tastes wrong
The chart gets you into the right neighbourhood. Taste gets you the rest of the way, and the rule is the same on every grinder here:
| What you taste | What it means | Move |
|---|---|---|
| Sour, sharp, thin, empty finish | Under-extracted | Finer |
| Bitter, drying, harsh, ashy | Over-extracted | Coarser |
| Balanced but weak | Ratio, not grind | Hold |
| Balanced but overwhelming | Ratio, not grind | Hold |
On this dial, 2–3 clicks is one meaningful step. Change one thing per brew. The full method is in the V60 dial-in guide.
Coffee Aeye holds this chart for all 18 supported grinders and closes the loop on it. Rate a brew and it converts the fault you tasted into a concrete move — how many clicks on your C40, in your own dial numbers, not a vague "grind finer". Calibrate your two anchors once and every recipe in the app re-derives to your unit. Get it on Google Play — €4.29, one-time.
Convert a setting to another grinder
Settings do not transfer between grinders — click sizes, burr geometry and zero points all differ. The grinder converter maps a C40 setting onto any of the other 17 through the same universal scale this chart is built on.