Espresso grinder basics
Burr shape, burr size, adjustment and dosing. Four specifications that decide how a grinder feels to own, and which of them actually matter.
For espresso, adjustment resolution matters most — you need small enough steps to land on the shot you want. Burr size is a rough proxy for class. Burr shape (flat or conical) is the specification people argue about most and the one that changes the least.
Published 2026-08-30 · Last reviewed 2026-08-30
Most grinder spec sheets list four things that matter and several that do not. Here is how to read them.
Adjustment: the one that matters most
Espresso is sensitive to grind changes of a few microns. Move too far and a shot that ran in 28 seconds runs in 45.
Stepped grinders have fixed positions. Easy to return to, but you may want a setting between two clicks. What matters is not the total number of settings but how many sit inside the espresso range. The Baratza Encore ESP is the clearest example: Baratza splits its forty settings so that 1–20 are the espresso range and 21–40 are filter. Forty settings spread across every brew method, as on the Breville Smart Grinder Pro with sixty, leaves fewer where you need them.
Stepless grinders adjust continuously. The DF54 and Niche Zero both work this way. You can land anywhere, which is the point — and there are no reference numbers, so you keep your own.
Micro-stepped sits between: the Sette 270 has thirty macro steps with nine micro positions inside each.
Hand grinders quote the step directly. The 1Zpresso J-Ultra publishes 8 microns per click, 100 clicks per rotation — finer resolution than most electric grinders at any price.
Burr size
Larger burrs cut more coffee per rotation, so they grind faster and generate less heat. Diameter is a reasonable proxy for grinder class: 40–48mm is entry, 54–64mm is the middle, 63mm and up is where conicals get serious. The Niche Zero uses 63mm conicals; the DF54 uses 54mm flats.
It is a proxy, not a score. Alignment and burr geometry matter more than the number, and neither is published by anyone.
Burr shape
Flat burrs tend toward a narrower particle distribution, which many people read as clarity and separation. Conical burrs are cheaper to manufacture, run cooler, and are often described as producing a heavier, more forgiving cup.
That is genuinely the extent of what can be said responsibly. This is the specification with the largest gap between how much it is discussed and how much it decides.
Dosing
Hopper grinders hold beans on top. Faster in the morning; beans sit exposed to air; changing coffee means emptying it.
Single-dose grinders take exactly what you weigh in. Fresher, trivially easy to switch beans, and one more step before every shot. The DF54, Niche Zero and Fellow Opus are built this way.
Which you prefer says more about your mornings than about your coffee.
Retention
Grounds left inside the grinder between doses, which end up in the next shot slightly stale. Manufacturers make claims — DF64 Coffee states under 0.1 gram for the DF54 — and independent figures vary enormously with measurement method. We record what the manufacturer says, marked as a manufacturer claim, and we do not publish a number we cannot source.
In practice, single-dose designs retain less than hopper designs, and if you keep one coffee in the grinder for a week it barely matters either way.
Questions people actually ask
Flat or conical burrs -- which is better?
Neither. Flat burrs are often described as giving more clarity and separation, conical as giving a heavier, more forgiving cup. Burr quality and alignment matter far more than shape, and a good conical will beat a mediocre flat every time.
Do I need a stepless grinder?
It helps. Espresso responds to very small grind changes, and a stepped grinder can leave the shot you want between two clicks. Grinders with enough steps in the espresso range -- like the Encore ESP's twenty -- work fine.