How to Grind Coffee for Coarse Grind | The Sea-Salt Standard

Pouring hot water over coffee grounds that are too fine for the method is the fastest way to ruin a morning cup. A coarse grind—one that looks like chunky peppercorns or rough sand—isn’t optional for immersion brewing; it’s the single variable that separates a clean, rich French press from a muddy, over-extracted mess. Here is exactly what that grind looks like, how to dial it in with a burr grinder, and what to do when the flavor tells you you’re off.

What Is a Coarse Grind? The Visual and Measurable Standard

A coarse grind measures between 1300 and 1400 microns. That is noticeably larger than medium-coarse (1100–1300 µm, like coarse sand) and far bigger than a standard medium grind (800–1000 µm, beach-sand texture). The easiest check is touch and sight: the particles should feel like coarse sea salt and should not slip through your fingers like fine sand. If they look powdery or feel silky, they’re too fine for a French press or cold brew. Extra-coarse (1400–1600 µm, like rock salt) is slightly larger and is the standard for cold brew’s long 12- to 24-hour steep, though many cold brew recipes work fine with a standard coarse grind.

Why Burr Grinders Are the Only Real Option

Blade grinders chop beans unevenly, producing a mix of dust and boulders. That inconsistency guarantees sour bits (from the dust over-extracting) and weak bits (from the chunks under-extracting) in the same cup. A burr grinder—either electric or manual—crushes beans between two surfaces to a uniform size, which is the only way to reliably hit the 1300–1400 micron range. See our tested picks for the best burr grinder for coarse grinds if you’re shopping for one that locks in the right setting without guesswork.

How to Dial in a Coarse Grind: Step by Step

Getting the grind right takes about 30 seconds once you know your grinder’s dial. The sequence looks like this:

1. Confirm your method. Coarse is for French press and cold brew only. Chemex uses medium-coarse; espresso and AeroPress need fine grinds. Using coarse in a drip machine will produce weak, watery coffee.
2. Weigh your beans. Use roughly 0.38 ounces (10.6 grams) of whole beans per 6 ounces of water. A scale is far more reliable than a scoop because bean density varies by roast level.
3. Set your burr grinder. If you’re unsure where coarse falls on your grinder’s numbered dial, start near the loosest setting (largest gap) and gradually tighten until the grounds look like sea salt. The first batch is your test batch.
4. Grind. Electric burr grinders take less than 30 seconds for a single serving. Manual grinders work best with steady, pulsing turns—not one long cranking session—to keep the particle size even.
5. Verify by touch. Pinch a few grounds. They should feel gritty, not powdery. If they stick to your fingers or feel smooth, they’re too fine.

One common caveat: darker roasts are more brittle and produce more fines (dust) even at the same grind setting. If you switch from a light roast to a dark roast, you may need to nudge your grinder one click coarser to keep the brew from turning harsh.

Fixing Flavor by Adjusting Grind Size

Your taste buds are the final quality check. If the coffee tastes sour or weak—what baristas call under-extracted—the water passed through too quickly, and you need to grind slightly finer (tighten the burr setting one click at a time). If it tastes harsh, bitter, or astringent—over-extracted—the water sat too long or the particles were too fine, and you need to grind coarser (loosen the burr setting). This works for any brew method, but the starting point changes: a French press that tastes bitter likely needs a coarser grind than 1300 microns, while a press that tastes hollow probably needs a move toward medium-coarse. Adjust in small steps and taste again; one click on a quality burr grinder is enough to shift the flavor profile.