Somebody in a forum thread asks what grind setting to use for pour over, and forty people answer with numbers. Fourteen. Six point five. Eight clicks from zero. Three and a half on the dial.
Every one of those answers is useless to everyone else reading, and understanding why is genuinely useful. Grinder settings are not a unit of measurement. They are a position on one specific machine, and they do not translate to any other machine, sometimes not even to another copy of the same model.
Start with beans worth dialing in properly.
The Numbers Are Arbitrary by Design
A grind setting is a mechanical position, usually the distance between two burrs. Manufacturers label that adjustment however they like.
Some use numbered dials with arbitrary increments. Some use stepped clicks counted from a zero point where the burrs touch. Some use a continuous ring with no markings at all. Some print words like fine, medium, and coarse, which are even less transferable.
None of these are calibrated to a physical particle size. There is no industry standard saying that setting six equals four hundred microns. A number on one grinder is a position on that grinder's adjustment mechanism, nothing more.
So when someone says they brew pour over at fourteen, they have communicated one useful thing, which is that fourteen works on their machine. Applied to yours it is a random number.
Burr Geometry Changes Everything
Even if two grinders were labeled identically, the coffee coming out would differ, because the burrs themselves produce different results.
Conical burrs and flat burrs cut coffee differently. Flat burrs tend to produce a narrower particle distribution with a more uniform result, while conicals tend to produce a wider distribution with both more fines and more larger particles. A conical grinder set to produce the same average particle size as a flat grinder will still brew differently, because the spread around that average is not the same.
Burr size matters too. A larger burr set processes coffee with fewer passes and less recirculation, generally producing more consistency. Small burrs in an inexpensive grinder cut the same bean multiple times as it works its way out.
Burr geometry beyond that varies enormously. Tooth pattern, cutting angle, alignment, and material all change the particle distribution the machine produces. Two grinders with the same burr diameter and different tooth designs are not interchangeable.
And burr alignment is a real variable within a single model. Two units off the same production line can be aligned slightly differently, which shifts where the useful range sits on the dial. This is why even people with identical grinders find their settings do not match.
Blade Grinders Are a Separate Category
Worth naming directly, since it comes up constantly.
A blade grinder has no setting at all. It has a spinning blade smashing beans into whatever sizes result, controlled only by how long you run it. There is no adjustment mechanism because there is no gap being set.
The particle distribution from a blade grinder is enormously wide, with dust and large chunks in the same batch. The dust overextracts into bitterness while the chunks underextract into sourness, and the cup gets both. No setting from a burr grinder means anything here, and no amount of technique fully compensates.
Get coffee that shows you what your grinder can do.
The Coffee Itself Moves the Setting
Even on your own grinder, one number does not hold across coffees, and this catches people who think dialing in is something you do once.
Roast level changes bean hardness substantially. A light roast is dense and hard, resists the burrs, and produces coarser output at a given setting than a dark roast of the same coffee. Moving from a light to a dark roast usually requires going noticeably finer to hit the same brew time.
Density varies by origin and altitude. A high grown Kenyan is harder than a low grown Brazilian, and grinds differently at the same setting.
Freshness matters. Coffee degasses over weeks, and older beans behave differently in the burrs and in the brewer. The same coffee at four days and at four weeks often needs a different setting to produce the same drawdown.
Even humidity plays a role, since beans pick up moisture from the air and slightly softer beans grind slightly finer.
This is why every new bag needs dialing in, and why the process never quite ends. The setting is chasing a moving target.
What to Communicate Instead of a Number
Since settings do not transfer, the useful information is the outcome you are aiming for.
Brew time is the most practical shared reference. For a pour over, a total drawdown somewhere around two and a half to three and a half minutes for a standard recipe. For espresso, a target shot time in the range of twenty five to thirty two seconds for a given dose and yield. Those numbers are about how the coffee behaves, not about your equipment, so they mean the same thing to everyone.
Particle size in microns is the technically correct version, and a few people with the right equipment measure it. Most do not, which is fine, since brew time is a decent proxy.
Taste description works too. Sour and thin means underextracted, so go finer. Bitter and drying means overextracted, so go coarser. That is transferable advice regardless of what machine you own.
How to Actually Dial In
Work from a starting point and adjust in one direction with everything else fixed.
Start wherever your grinder's manual or general reputation puts the category. Coarse for French press, medium for pour over, fine for espresso, and accept that these are rough.
Brew, and time it. Note whether the time landed in the target range.
Taste it black and decide whether it is sour or bitter. Sour and fast means go finer. Bitter and slow means go coarser. Sour and slow, or bitter and fast, means something other than grind is wrong, usually water temperature or a channeling problem.
Change one step at a time. Big jumps make it hard to know where the good range sits, and grinders vary in how much a single step moves things. On some machines one click is a large change, on others it barely registers.
Keep a note of what worked for each coffee on your own machine. That log is genuinely valuable to you and worthless to anyone else, which is the whole point.
Why This Is Worth Understanding
The practical consequence is that you cannot shortcut dialing in by copying somebody's numbers, and the sooner you accept that the faster you get to good coffee.
It also means grind advice from a roaster is necessarily general. When a bag says medium grind for pour over, that is a category, not an instruction, and the roaster knows it. Nobody selling coffee has any way to know what machine you own.
And it explains why upgrading a grinder often improves coffee more than upgrading a brewer. You are not buying a better number. You are buying a narrower particle distribution, which means more of your dose extracting at the same rate, which is most of what consistency in brewing amounts to.
Your setting is yours. It describes a position inside your machine at this moment with this bag of coffee, and that is exactly as far as it goes.
Find your setting with coffee that is worth the trouble.
All images shown in this blog are sourced from pexels.com.