Which to buy · Every setting
Fellow Opus vs Mahlkönig X54
Conical against flat — the Opus's scale curves where the other runs straight. The Opus is numbered 1–11; the X54 is numbered 1–35.
Which to buy
Choose the
Opus if you…
- want fixed steps you can return to exactly — 41 on the dial, plus a micro-adjust ring
- want 40 mm conical burrs
- want a lighter grinder — 2.3 kg
Choose the
X54 if you…
- want 54 mm flat burrs and stepless adjustment, espresso to cold brew
- want four timed presets on an LED display
- want a quiet grinder — Mahlkönig says under 70 dB(A)
Shop links are affiliate links: BrewMark earns a commission if you buy through one, at no extra cost to you. The verdicts were written without regard to it.
Fellow now sells the Opus 2 in place of the original; the settings on this page are for the original.
Sources: Fellow — Opus (archived) · Mahlkönig USA — X54 Allround Home Grinder
| Opus | X54 | |
|---|---|---|
| Brand | Fellow | Mahlkönig |
| Scale | Numbered dial | Numbered dial |
| Dial range | 1 – 11 | 1 – 35 |
| Burrs | Conical | Flat |
| Espresso → filter | 5.7 numbers | 20.1 numbers |
| Filter → coarse | 3.9 numbers | 13.9 numbers |
The same number means different things
Both grinders use a numbered dial, which makes it tempting to copy a number straight across. Setting 6 sits at grind index 34.2 on the Opus but 11.7 on the X54 — far enough apart to change the cup.
Converting a setting
If a recipe quotes a setting for one of these grinders, read across for the equivalent on the other. Rows are spaced evenly by grind size, not by dial number — on a conical burr those are not the same thing.
| Opus | X54 |
|---|---|
| 1.2 | 1 |
| 2 | 8.3 |
| 3.2 | 12.9 |
| 5.3 | 17.4 |
| 7.1 | 21.6 |
| 8 | 23.9 |
| 8.2 | 26.2 |
| 8.3 | 28.6 |
| 9.1 | 30.4 |
| 9.3 | 31.9 |
| 10.2 | 33.5 |
| 11 | 35 |
| X54 | Opus |
|---|---|
| 1 | 1.2 |
| 4.6 | 1.2 |
| 8.3 | 2 |
| 12.9 | 3.2 |
| 17.4 | 5.3 |
| 21.6 | 7.1 |
| 23.9 | 8 |
| 26.2 | 8.2 |
| 28.6 | 8.3 |
| 30.4 | 9.1 |
| 31.9 | 9.3 |
| 33.5 | 10.2 |
| 35 | 11 |
Side by side, by brew method
Where each grinder lands for the same brew, worked out from its own dial curve.
| Method | Opus | X54 |
|---|---|---|
| Espresso | 1.2 | 3.1 |
| Moka pot | 1.3 | 7.4 |
| AeroPress (short steep) | 3.2 | 12.9 |
| Pour over — V60 / cone | 6.3 | 20 |
| Siphon | 7.2 | 21.7 |
| Pour over — flat bottom | 7.3 | 22.5 |
| Steep and release — Clever / Switch | 8 | 23.3 |
| Drip / batch brew | 8 | 23.9 |
| Cupping | 8 | 24.5 |
| Chemex | 8.2 | 26.1 |
| French press | 9 | 29.9 |
| Cold brew | 10 | 32.8 |
The shape of each dial
Where the connectors bunch, that grinder’s dial is compressed and single steps count for more. Comparing the two shapes tells you which gives finer control, and where.
Fellow Opus
Mahlkönig X54
Dialing in the Opus
Marketed as all-purpose, and it genuinely does cover more range than the Ode, but the espresso end is workable rather than good — expect to chase it. Where it earns its place is the coarse end: cold brew and French press come out notably even. If you bought the Opus mainly for espresso, dial it as a brew grinder first and judge it there.
Dialing in the X54
Mahlkönig's home grinder, and much more conventional than the EK that shares its badge. Genuinely all-purpose with a usable espresso end, though the resolution down there is nothing like a dedicated espresso grinder's.