Cold Brew Grind Size: Coarse, and Settings for Popular Grinders

Cold brew wants a coarse grind: Seattle Coffee Gear's guide to the Toddy system describes it as "the coarseness of raw sugar or coarse salt." On most grinders that means the coarse end of the dial, a step or more past where you'd set it for French press.

That is the whole answer for most people. The rest of this post explains why cold brew needs to be that coarse, how grind works with steep time and ratio, what to change when a batch goes wrong, and where to start on the grinder you own.

Why cold brew needs a coarse grind

Three things push cold brew toward the coarse end.

The steep is long. Cold brew sits in water for half a day or more. OXO's manual for its compact brewer says 12 to 24 hours on the counter, and the Toddy instructions give the same 12 to 24 hours. With that much contact time, the grounds don't need much surface area to give up their flavor. Breville's Sage site puts it plainly: "Extra coarse grinds are key for cold brew coffee," because the long brew "requires minimal surface area to prevent bitterness."

It has to drain. Most home cold brew drains through a felt pad, a mesh, or a paper filter at the end of the steep. Fine particles pack into that filter. The Toddy guide warns that "a too-fine grind clogs the felt filter and slows or stops drainage." A coarse grind leaves gaps between the grounds for the concentrate to run through.

Fines become silt. Every grinder makes some dust along with the main particle size. In cold brew, that dust either clogs the filter or slips through it. The Toddy guide's fix for cloudy concentrate is a coarser grind, a paper filter bag inside the felt, or both.

So coarse is not about flavor alone. It's what lets the brewer work at all.

What cold brew grind looks like

In words: coarse and chunky, with visible separate pieces. The two comparisons makers use are raw sugar and coarse salt. It should feel gritty between your fingers, not powdery, and it should not clump.

It sits at the far end of the range. For reference, drip coffee grounds have a median particle size of about 750–900 µm (how we source micron figures). Cold brew is clearly coarser than that, and a bit coarser than French press. If you already know your French press setting, cold brew is usually a few steps past it on the same dial. You can see where every method falls on one scale on the grind size chart.

If your grounds look like sand or anything finer, you've gone too far. Go coarser.

How grind works with steep time and ratio

Cold brew has three levers: grind, time, and the amount of coffee. They trade off against each other, which is why recipes disagree so much.

Steep time

The makers give long windows:

• OXO compact brewer: 12 to 24 hours on the counter, or 20 to 24 hours in the fridge.
• Toddy (Equal Exchange's instructions): 12 to 24 hours, starting at 12.
• Toddy (Seattle Coffee Gear's guide): 12 to 24 hours in the fridge. Steeping 18 to 24 hours "produces a stronger, more robust concentrate."

Notice OXO's fridge window starts later than its counter window. Cold slows extraction, so a fridge steep needs more hours to reach the same strength. If you move your brewer into the fridge, add time rather than grinding finer.

Ratio

Most home cold brew is a concentrate you dilute later, so the brewing ratio is strong:

• OXO: 175 g of coffee to 700 mL of water. That's 1 part coffee to 4 parts water. OXO then recommends diluting 1 part concentrate with 2 or 3 parts water or milk.
• Toddy: 340 g of coffee to 7 cups (1.65 L) of water, which works out to roughly 1 to 5. Both Toddy guides suggest diluting 1 part concentrate with 1 part water.

BrewMark's own cold brew concentrate guide is lighter: 1 part coffee to 8 parts water, 16 hours at room temperature, diluted 1:1 to serve. Pick one recipe and keep it steady while you adjust grind. Use the brew calculator to scale any of them to the jar you have.

How they interact

Grind sets how fast extraction happens. Time and dose set how far it goes. A practical way to use that:

• Get the grind coarse enough that the brewer drains cleanly. That's your floor.
• Then adjust strength with time and dose, not with grind. The Toddy guide's advice for a weak batch is to steep longer (up to 24 hours) or add coffee. For a batch that's too strong, it says to dilute more or steep for less time.
• Only grind finer if you're already at the long end of the steep and the full dose, and the coffee still tastes thin. The Toddy guide notes that "too coarse a grind extracts less."

Troubleshooting cold brew by grind

It drains very slowly, or stops. The grind is too fine. The Toddy guide says to grind coarser next batch. Pouring the water gently also helps, so the grounds don't pack down.

The concentrate is cloudy or muddy. Fines are getting through the filter. Grind coarser, add a paper filter as a second layer (both OXO and Toddy suggest paper as an extra layer), and don't squeeze the grounds. The Toddy guide says pressing "forces fine particles through the filter."

It tastes bitter or harsh. A grind that is too fine for a long steep is the usual cause. Breville's Sage guide ties the coarse grind directly to preventing bitterness. Go coarser before you cut the steep short. Our bitter coffee guide walks through the other causes.

It tastes weak or watery. Steep longer or use more coffee first. If you're already at 24 hours and a full dose, step the grind one notch finer. Also check your dilution: cold brew concentrate is meant to be cut, but OXO's 1:2 or 1:3 is a lot more water than Toddy's 1:1.

It tastes flat after a few days. That's storage, not grind. Seattle Coffee Gear says Toddy concentrate keeps for up to two weeks in the fridge; brew smaller batches if yours fades before then.

Starting settings on popular grinders

These are the cold brew rows from each grinder's BrewMark settings page. Start at the setting, then move within the range by taste.

Starting points from each maker's own chart, collected on BrewMark's settings pages. Every grinder drifts; adjust by taste.

The Fellow and OXO rows come straight from the maker's chart. The Baratza, Comandante, 1Zpresso and Timemore rows are marked estimated on BrewMark's pages: placed on the same dial curve as the maker's published settings, not taken from a maker's chart. Each grinder's page says which is which.

Clicks on hand grinders are counted from zero, with the burrs closed. The same number on two different grinders is not the same size. To carry a setting from one grinder to another, use the grind converter. To see cold brew next to every other method, use the master grind size chart.

If you're shopping, cold brew is easy on a grinder: it needs a dial that goes coarse enough and a burr set that doesn't make much dust at that end. The grinder finder, set to cold brew, is the place to start comparing.

A note on hand grinders

Cold brew uses a lot of coffee per batch. The Toddy recipe calls for 340 g, and OXO's compact brewer takes 175 g. On a hand grinder, that's a long session. If you make cold brew every week, an electric grinder will save your arm. The grinder settings hub shows both kinds.

Next steps

• Find your grinder's full chart in the grinder settings hub, or compare every method on the grind size chart.
• Brew a batch with the BrewMark cold brew concentrate guide.
• Read what cold brew and immersion brewing mean in the glossary.
• New grinder? Start with how to dial in a new grinder.
• Making hot coarse-ground coffee too? The French press grind size guide covers the next step finer.