Cold Brew French Press: A Step-by-Step Method That Works

To make cold brew in a French press, stir coarse ground coffee into cold water, put the lid on, and let it steep for 12 to 24 hours. Then press the plunger down slowly and pour the coffee through a paper filter to catch the fine silt the mesh lets through.

That's the method Bodum gives for its own French-press-style cold brewer, and it's close to what America's Test Kitchen settled on. Below are the steps with the numbers each source uses, what to do about sediment, how much to dilute, and how long it keeps. If you only need the grind, the cold brew grind size guide covers that in depth.

What you need

• A French press. Any size works. Bodum's Chambord instructions say to leave at least 1 inch (2.5 cm) of space at the top of the carafe, so don't plan on filling it to the brim.
• Whole bean coffee and a burr grinder that goes coarse. America's Test Kitchen recommends freshly ground beans, because pre-ground coffee loses flavor quickly, and found medium roasts "taste more like coffee and less like the roasting process."
• Cold or room-temperature water. Filtered water if your tap water tastes off.
• A kitchen scale. Ratios by weight are much easier to repeat.
• A paper coffee filter and a fine-mesh strainer for the second filtering. Optional, but it's the step that makes the biggest difference to a French press cold brew.

The ratio: how much coffee per water

Cold brew in a French press uses far more coffee than hot French press. Bodum's hot-brew instructions for the Chambord call for one rounded teaspoon (or one Bodum scoop) of coarse coffee per 4 oz cup of water. For cold brew, Bodum's BEAN cold brewer instructions say to use "twice your usual amount."

By weight, the sources land in a similar zone:

• Tom's Guide (written by a former barista) says most people use 1:8 coffee to water, and the author goes to about 1:10 to dilute less. In a 32 oz press, that's about 90 g of coffee to roughly 30 oz of water.
• BrewMark's cold brew concentrate guide uses 1:8: 100 g of coffee to 800 g of water.
• Toddy's standard recipe (from Seattle Coffee Gear's guide) is stronger: 340 g of coffee to 1.65 L of water, roughly 1:5, which makes a concentrate meant to be cut 1:1.

A 1:8 ratio is a good place to start in a French press. It's strong enough to dilute but not so dense that the grounds turn into sludge. For the full trade-off between strong concentrates and ready-to-drink batches, see the cold brew ratio guide. To scale any of these to the size of your press, use the brew calculator.

The grind: coarse

Every source here says coarse. Tom's Guide grinds "much coarser than you would for hot coffee" and suggests going as coarse as flaky salt if the cold brew tastes bad. Seattle Coffee Gear's Toddy guide describes the right size as "the coarseness of raw sugar or coarse salt."

In a French press, coarse matters for two reasons. The long steep doesn't need much surface area, and the metal mesh only holds back particles above a certain size. Anything finer slips past the screen and ends up in your glass as silt. If you already have a French press setting you like, cold brew is usually a step or more coarser on the same dial. The cold brew grind size guide explains why, and the table further down gives a starting setting for five popular grinders.

Step by step

1. Grind the coffee coarse and add it to the empty carafe with the plunger removed.
2. Add the water and stir. Bodum says to add fresh cold water and stir with a plastic spoon. (Bodum suggests plastic or wood with its glass carafes.)
3. Stir again once the raft forms. America's Test Kitchen notes that about 10 minutes after the coffee and water meet, a solid raft of grounds forms on the surface. Stir it back down so all the coffee is in contact with the water.
4. Cover and steep. Put the lid on with the plunger raised. Bodum's BEAN instructions steep in the refrigerator for 12 to 24 hours. America's Test Kitchen steeps at room temperature; its editor ran brews from 12 hours to 72 hours, and found 24 hours "consistently the sweet spot." Tom's Guide steeps at least 12 hours, sometimes 24, and warns against going past 24.
5. Plunge slowly. Bodum says to plunge "gently but firmly." Tom's Guide says "very slowly and carefully." Seattle Coffee Gear's Toddy guide makes a related point about its own filter: pressing or squeezing the grounds clouds the concentrate.
6. Pour it off the grounds. Don't leave the finished coffee sitting on the spent grounds in the press. Pour it out right away, either into a jar or through the second filter below.

Fridge or counter? Both work. The BrewMark concentrate guide steeps 16 hours at room temperature rather than 24 in the fridge, because cold slows extraction enough that a fridge steep needs far longer to reach the same strength. If you steep in the fridge, plan on the long end of Bodum's 12 to 24 hours.

Filter it a second time to get rid of silt

A French press screen lets fine particles through. In a 4-minute hot brew that's part of the style. In a batch you'll drink over several days, the silt settles into a muddy layer at the bottom of the jar and keeps adding grit to every glass.

America's Test Kitchen's fix is simple: after steeping, pour the concentrate into a fine-mesh strainer lined with a coffee filter, set over a pitcher or large measuring cup. Most of it runs through on its own. ATK says it helps to gently clear the sediment with a rubber spatula so the last bit drains. Tom's Guide suggests a cheesecloth if your press's screen isn't fine enough.

The same logic is behind Seattle Coffee Gear's advice for the Toddy: a paper filter bag "catches fine particles the felt filter may miss." Paper is the tightest filter most kitchens have, so it's worth the extra few minutes.

Dilute to taste

What comes out of the press is usually a concentrate. How much you cut it depends on the ratio you brewed:

• Tom's Guide lists not diluting as one of the common reasons cold brew tastes bad: "cold brew is supposed to be mixed with water, ice, and milk."
• The BrewMark concentrate guide (1:8) dilutes 1:1 with water or milk.
• Seattle Coffee Gear's Toddy guide (roughly 1:5) also starts at 1:1 with water, milk, or ice, and suggests 1 part concentrate to 1 to 2 parts hot water if you want it hot.

Start at 1:1, taste, and add more water if it's too strong. Brewed at 1:10 like the Tom's Guide author, you may barely need to dilute at all.

How long French press cold brew keeps

Store it in a sealed jar or bottle in the fridge, not in the press. The sources vary:

• Tom's Guide: about 5 days in an airtight container.
• BrewMark's concentrate guide: about a week.
• Seattle Coffee Gear's Toddy guide: up to 2 weeks for Toddy concentrate.

The shorter numbers are the safer ones for a French press batch, which carries more fines than a felt-filtered Toddy. If yours tastes flat before it's gone, brew smaller batches.

Starting settings on popular grinders

Starting points from BrewMark's settings pages, which take them from each maker's own chart where one exists (rows marked * are estimated on the same dial). Every grinder drifts; adjust by taste.

Hand-grinder clicks are counted from zero with the burrs closed, and the same number means different sizes on different grinders. To see cold brew next to every other method on one scale, open the master grind size chart. If you're choosing a grinder, the grinder finder set to cold brew compares the ones that reach a cold brew grind.

Troubleshooting

Muddy or gritty. Grind coarser, plunge slower, and add the paper-filter step. If you're still getting grit, check that you're pouring off the grounds right after plunging rather than storing the coffee in the press.

Bitter or harsh. Seattle Coffee Gear's Toddy guide blames pressing on the grounds for cloudiness, and Tom's Guide lists grinding too fine and steeping past 24 hours among the reasons cold brew tastes bad. Fix the grind first, then shorten the steep. The bitter coffee guide covers other causes.

Weak or watery. Check the dilution before anything else. Then steep longer or add coffee, as the Toddy guide suggests for a weak batch. Only grind finer once you're at 24 hours and a full dose.

Cold brew vs hot French press

The two use the same pot but very different numbers. Hot French press, per Bodum's Chambord instructions, is a four-minute brew in water at about 92–96°C (roughly 198–205°F). Cold brew swaps heat for time and roughly doubles the coffee. For the hot method, see the French press brewing guide and the French press coffee ratio guide.

Next steps

• Find your grinder 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 why the grind matters so much in the cold brew grind size guide, and what fines are.
• Switching grinders? Convert your settings between grinders.