Burr Grinder

A burr grinder grinds coffee between two grooved surfaces, the burrs, set a chosen distance apart. That gap decides the size of the grounds, so every particle comes out roughly the same, and you can set it fine for espresso or coarse for a French press. It’s the single most useful upgrade for home coffee. This page explains the choices: burr or blade, conical or flat, hand or electric.

The short version

• Burr, not blade. Burrs give a consistent, adjustable size; blades give a mix.
• Conical burrs: more fines and body, run cooler, retain less coffee.
• Flat burrs: fewer fines and more clarity, spin faster, retain more.
• Hand grinders are fine for a cup or two; electric for bigger batches.
• Stepless adjustment allows tiny changes; numbered steps are easier to repeat.

Why is a burr grinder better than a blade grinder?

Because it controls the size. A burr grinder’s particles are a uniform size determined by the gap between the burrs, and the burrs heat the coffee less by friction than a blade “chopper”, Wikipedia says. Blade grinders produce an undesirable wide range of sizes. In a mix of dust and boulders, the dust over-extracts and turns bitter while the boulders under-extract and taste sour, so you can get both in one cup. Honest Coffee Guide leaves blade grinders out of its grind size chart for that reason.

What’s the difference between conical and flat burrs?

Conical burrs are a cone turning inside a ring. Beans fall in from above and are crushed smaller and smaller as gravity pulls them down. Flat burrs are two parallel discs, one turning. Beans enter through the centre and are ground as they’re flung outwards, so flat burrs have to spin faster to push coffee through, Honest Coffee Guide explains.

	Conical burrs	Flat burrs
Shape	Cone inside a ring, vertical	Two parallel discs
What moves the coffee	Gravity	Centrifugal force; faster spin
Fines	Generally more	Generally fewer
Cup	More body and texture	More clarity, less body
Heat	Run cooler	Heat up more in long sessions
Retention	Less coffee left inside	More left inside; clean them out
Power	Hand or electric	Almost always electric
Price	Lower on average	Higher on average

Sources: Honest Coffee Guide; Mahlkönig. Both agree on heat and retention.

Are flat burrs better for espresso?

This is where the sources split:

Source	Claim
Mahlkönig (a flat-burr grinder maker)	Flat burrs give a unimodal grind, almost all one size; conical burrs always give a bimodal one, which harms espresso. Dedicated espresso grinders almost universally use flat burrs
Honest Coffee Guide	Conical burrs’ extra fines give more body, which can be especially desirable for espresso and moka pots; flat burrs are often favoured for French press and filter. Neither is objectively better
Philippine particle-size study (2022)	Coffee grounds always show a bimodal spectrum, a small fines peak beside the main peak; flat burrs produced fewer fines than conical ones

Sources as listed. “Flat is unimodal, conical bimodal” is a generalisation, Honest Coffee Guide adds: some conical grinders grind more evenly than some flat ones. Compare grinders at the same price, not burr shapes in the abstract.

Hand or electric?

	Hand grinder	Electric grinder
Burrs	Usually conical; a few, such as the OE Apex, are flat	Conical or flat
Speed	Slow; many turns per cup	Fast, no effort
Best for	One or two cups, travel, quiet mornings	Bigger batches, households, espresso every day

Sources: Wikipedia; Honest Coffee Guide. Precise manual grinders have become more popular for pour-over and espresso in the 2020s, Wikipedia says. Cheaper electric burr grinders drive the burrs through reduction gears, which are noisier and wear sooner than the direct-drive motors of commercial grinders.

What else matters when buying a grinder?

• Adjustment. Stepped grinders click through numbered settings you can repeat; stepless ones adjust continuously.
• Burr material. Stainless steel and ceramic are both used for coffee, Wikipedia notes; ceramic doesn’t corrode.
• Retention and cleaning. Grounds left inside go stale overnight and taint the next brew, so a grinder you can clear out easily matters if you make one coffee a day, Honest Coffee Guide says.
• Turkish coffee. Its powder-fine grind is beyond cheap electric and simple hand grinders; it needs a special, precise one. See the Turkish coffee grinder.

A short history

The first coffee grinder was made in 1799 by Richard Dearmann, a Birmingham blacksmith, and in 1818 Increase Wilson patented the first wall-mounted coffee grinder in the US, Wikipedia says.

Grinders and other kit guides

• Coffee grind size chart: the setting for every brewing method.
• Turkish coffee grinder: for the finest grind of all.
• Coffee scale: weigh what you grind.