How to Fold Chemex Filter (2026): Easy Steps

Quick answer: which filter do you have?

Pre-folded squares need opening, not more creases. Unfolded FP-1 circles need two folds before opening. Half-moon FP-2/FP-2N paper needs its own folding method for the 3-cup Chemex or FUNNEX. In each case, finish with the thicker side toward the spout, following CHEMEX Filter Folding 101.

Once the paper is sorted, Best Pour Over Accessories (2026): 6 Worth Buying covers kettles, scales, drippers, and other tools for the rest of your setup.

What you'll need

You only need a compatible paper filter and your brewer to fold and seat the cone. Add warm water when you're ready to rinse it. A kettle, scale, or grinder is not needed to fold the paper, so leave the rest of your brewing kit aside for now.

• A Chemex: check its size before choosing paper.
• Matching Chemex Bonded Filters: check compatibility on the package.
• Warm water: for wetting the seated filter.

The example brewer uses non-porous borosilicate glass, weighs 1.35 pounds, and takes Chemex Bonded Filters, which aren't included. View the example brewer →

Don't own a brewer yet? Best Pour Over Coffee Maker (2026): 6 Top Picks helps you choose one and check its filter requirements.

Step-by-step: fold and place the paper

Identify the paper first, form its cone, and seat it before wetting it. Don't add extra folds to a pre-folded filter or use the circle method on a half-moon. Your final check is simple: a thicker wall beside the spout and a clear air channel underneath it.

1. Check the shape before creasing

Look at the paper dry. A pre-folded square or circle opens from its existing creases. A flat FP-1 circle needs folding. For FP-2/FP-2N half-moon paper, use the smaller-brewer method below; don't assume all Chemex filters fit every brewer.

2. Form the cone

For pre-folded paper, separate one sheet from the other three, like opening a thin paper pocket. For an unfolded circle, CHEMEX says to fold it in half, then in half again. Open one layer away from three to create the cone.

For a half-moon, fold it along its crease, fold the small projecting tab against the paper, then open the cone. Use the manufacturer's folding diagram for orientation; Sweet Maria's 3-cup folding demonstration also shows this unusual shape.

3. Place three layers beside the spout

Set the cone into the brewer with its point down. Turn the three-layer wall toward the pouring spout and gently press it against the glass, as CHEMEX instructs. Viewed from above: spout, thick paper wall, open pocket, thin paper wall.

4. Wet the seated filter

Pour warm water over the paper until it's evenly wet, then discard the rinse water. Follow CHEMEX brewing instructions for brewer care and setup. Pour gently rather than blasting one spot with water.

A gooseneck is optional for this job. For controlled brewing pours afterward, see Best Gooseneck Kettle for Pour Over (2026): 5 Smart Picks.

5. Check the spout's air path

Look down the spout channel. The wet paper should bridge it, not slump into it like a wet tissue. If it has sagged, gently reseat the empty filter before adding grounds. Don't poke at it once it's full of hot water and coffee.

Common mistakes: fix the visible symptom

A cone that won't sit open, a split tip, or a rim sitting too low calls for a paper check, not a new brew recipe. Inspect it while empty. If the paper is damaged, start with a fresh sheet rather than trying to patch a hole with another fold.

• The cone stays flat: check that you've opened a pocket, not just spread the outer corners.
• The tip has torn: replace it. Avoid pulling hard on wet paper.
• The filter sits oddly low: recheck the package's brewer compatibility before filling it.

Troubleshooting: is the fold actually the problem?

Check paper placement if the filter visibly slumps or blocks the spout. If the empty, rinsed cone sits correctly but coffee drains slowly, don't keep inventing new folds. Grind size and the amount of coffee are separate checks, and changing both at once makes the cause harder to spot.

Paper slumps into the spout

Before brewing, reopen the cone and confirm the one-layer/three-layer split. CHEMEX specifies the thicker side at the spout for support. Replace a filter that won't stay seated, and never reach into a brewer full of hot coffee.

Placement looks right, but brewing is slow

Homegrounds' Chemex guide points readers toward a medium-coarse grind. If yours looks powdery, try a coarser setting next time. Also check your coffee amount against your chosen recipe; extra coffee isn't a folding error. Change one thing per brew.

Frequently asked questions