Grind your medium-roast coffee coarse, about the texture of kosher salt, before it goes into a French press. Barista Hustle puts that texture in numbers at roughly 1,000 to 1,300 microns.
Coarse matters because a French press is an immersion brewer, which means the grounds soak in the full pot of water for about four minutes. Fine particles over-extract during that long soak and slip past the metal mesh screen as sludge.
Starbucks and the National Coffee Association both list coarse as the French press setting. For a medium roast, lean toward the finer edge of coarse, since medium roasts give up flavor a bit more slowly.
What Coarse Looks and Feels Like
A proper French press grind looks like kosher salt or coarse breadcrumbs and feels gritty between your fingers. Rub a pinch together: you want distinct grains, not powder.
A micron is one thousandth of a millimeter, and kosher-salt grounds sit at roughly 1,000 to 1,300 microns across. That size is big enough to hold flavor back during a long soak.
Use the table below to judge your grind by sight and touch before you brew.
| What the grounds look and feel like | Where that lands | What the cup tells you |
| Gritty grains like kosher salt or coarse breadcrumbs | Target zone, about 1,000 to 1,300 microns | Balanced strength with full body |
| Powder that sticks to your fingers and the grinder | Too fine for immersion brewing | Bitter, muddy sips and a plunger that fights back |
| Chunky flakes mixed with broken half-beans | Too coarse | Sour, thin, watery coffee |
| A touch finer than kosher salt, near coarse sand | Still useful for medium roasts | Good sweetness, with extra silt in the final pour |
Texture is the shortcut, but the reason behind it lives in how the press brews.
Why Grind Size Matters So Much in a French Press
A French press keeps every ground underwater from the first second to the pour. Grind size sets how much bean surface area the water can reach, which controls how fast flavor leaves the grounds.
Fine particles carry the most surface area, so they extract the fastest and the harshest. They are also small enough to pass through the metal mesh screen, which is what makes the final sips muddy.
Starbucks’ home French press guide and the National Coffee Association both name coarse grounds as the grind for this method. The Specialty Coffee Association defines proper extraction as 18 to 22 percent of the grounds dissolving into the water.
When the grind is right, the press gives a rich, sediment-light cup with heavy body and chocolate-nut notes playing forward for medium roasts.
Does Medium Roast Change the Grind?
“Medium” shows up twice in this question, and the words do not mean the same thing: a medium roast can still need a coarse grind. Roast level describes how long the beans were roasted, while grind size describes how small you chop them afterward.
James Hoffmann, author of The World Atlas of Coffee, calls a medium-coarse grind ideal for medium roasts in a French press. He also warns that grinding extremely coarse pushes the cup toward under-extraction.
The reason is density. Medium roasts hold more of their original structure than dark roasts, so their flavor dissolves a little more slowly in hot water.
That slower pace explains why a French press flatters a medium roast. The long soak gives denser beans time to catch up, so the tighter end of coarse stays smooth instead of harsh.
Barista Hustle describes the same move: medium-density roasts get tightened slightly below classic dark-roast coarse, which balances sweetness and acidity.
None of that matters if your grinder cannot find the texture, so tool choice comes next.
Get the Grind With the Right Grinder
A burr grinder crushes beans between two textured plates, and that is what French press brewing needs. Blade grinders whack beans into uneven fragments, so every batch carries powder alongside chunks.
Electric burr grinders make the routine easy. The Baratza Encore offers a numbered dial that runs deep into the coarse zone.
Key Specifications:
- Burr type: conical steel
- Power: electric countertop
- Settings: numbered dial with generous coarse range
- Style: hopper stores a whole bag of beans
Prefer something cheaper and quieter? The Timemore C3 hand grinder stows in a drawer and travels well.
Key Specifications:
- Burr type: stainless steel conical
- Power: hand crank
- Settings: stepped clicks
- Use: travel and small kitchens
If you buy pre-ground coffee instead, pick a bag ground for French press rather than one meant for a paper-filter machine. Ground coffee also loses aroma faster than whole beans, so keep pre-ground bags small.
With the grinder sorted, the next job is holding every other variable still.
Keep the Rest of the Brew Steady
Weigh 30 grams of coffee and pour 450 to 480 grams of water over it for a 1:15 to 1:16 ratio. A small digital coffee scale makes those numbers repeatable.
Water temperature, ratio, and steep time all shape the cup alongside grind size, so change only one thing between brews. Keep the water just off the boil and the steep near four minutes, and any taste shift points back at the grind.
For a cleaner pour, use James Hoffmann’s finish: stir the crust at four minutes, skim what floats, then let the pot sit so particles settle. Press the screen only to just under the surface, then pour gently and stop before the last murky ounce.
It works the same in a classic glass Bodum Chambord or any pot with the same mesh plunger.
Key Specifications:
- Type: classic French press
- Carafe: borosilicate glass
- Filter: stainless steel mesh plunger
- Frame: chrome coating protects the glass
Stale beans taste flat at any grind setting, so check how fresh medium roast beans should be before blaming your dial.
From there, the cup itself tells you which way to turn.
Fix the Flavor by Moving the Grind
Bitter, harsh, or drying cups call for a step toward coarser, one adjustment at a time. Change one setting per brew, then taste again before touching anything else.
Sour, thin, or grassy cups can indicate under-extraction, so take one step finer on the next brew. Let the spoon settle the question, because taste is the only scoreboard that counts.
You can also stretch the steep or nudge the water temperature, but change the grind first so each test points at one variable. Save those other levers for after the grind feels close.
Silt in the final pours can indicate fines, the powdery dust created during grinding. Skim before pressing, plunge shallow, and rely on a burr grinder for the rest.
Other brewers pose different questions for the same beans. Dialing in the right grind for a drip machine is its own job, and what cold brew expects from grounds is another conversation entirely.
Counter Culture Coffee builds that same taste-and-adjust loop into its own French press guide, so you are in good company. Treat your first brew as a rough draft and the fourth as the keeper.
Grind your medium roast coarse for the French press, kosher-salt sized at about 1,000 to 1,300 microns, and ease toward medium-coarse if it tastes thin. Start with 30 grams of coffee today, brew four minutes, and adjust one small step at a time.