1Zpresso J-Max S grind settings.
The fine-resolution 1Zpresso: 8.8 µm per click, which is why every number here is higher than on the JX-Pro.
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 | J-Max clicks |
|---|---|
| Espresso anchor | 31 ± 1 |
| Moka pot | 45 ± 1 |
| AeroPress (short, fine) | 52 ± 1 |
| V60 / pour-over | 65 ± 1 |
| Kalita Wave | 72 ± 1 |
| Chemex / batch drip | 79 ± 1 |
| Clever / switch immersion | 93 ± 1 |
| French press anchor | 120 ± 1 |
| Cold brew | 134 ± 1 |
One click on this grinder moves the grind by about 0.07 of a point on the 1–10 universal scale — so roughly 7 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 J-Max 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 31 and French press at 120. 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
An external numbered ring like the JX-Pro, but with a finer thread pitch — 8.8 µm per click against the JX-Pro's 12.5 µm. The same physical grind size therefore lands at a noticeably higher click count, and the anchors scale accordingly: espresso at 31, French press at 120.
Calibrating the chart to your own J-Max
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 J-Max
This is where the espresso resolution lives.
At 8.8 µm a click, you get genuinely fine control across the espresso band — the reason to choose a J-Max over a JX-Pro.
Every JX-Pro number is wrong here, by about 40%.
The ratio between the two click sizes is what separates the charts. Reading across from a JX-Pro will land you far too coarse.
The coarse end is long but rarely used.
French press at 120 of a possible 170 means the top third of the dial exists mainly for cold brew.
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, 7–14 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 J-Max, 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 J-Max setting onto any of the other 17 through the same universal scale this chart is built on.