Coffee Facts

How To Fold Chemex Filters

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People often overlook the filter in the coffee-making process. Warming the coffee maker, measuring the grounds, and slowly pouring the hot water are important parts of the Chemex pour-over process.

Buying pre-folded filters saves time, but have you ever wondered how to fold Chemex filters yourself? It’s so simple and gives you even more control over your coffee making.

Let’s take a moment to look at the Chemex filter itself

The Filters

Original bonded Chemex filters, whether pre-folded or unfolded, are made from a heavier paper than traditional coffee filters and are either oxygen-washed white, a bleach alternative, or the natural, unprocessed form comes in a light brown color. 

Chemex sells three shapes for unfolded filters: 

  • Square: The traditional shape 
  • Circle: Lays flush and can be used for other cone coffeemakers
  • Half-moon: More stable than a circle

How to Fold a Chemex Filter

You can make Chemex coffee with any of the shapes, and each requires a slightly different fold. 

Many coffee lovers attest to enjoying their cup of coffee more when they fold their coffee filter because it becomes a part of the coffee ritual, like warming the brewer and slowly pouring the water. 

Circle

Folding Chemex Filter
  1. Fold the circle in half.
  2. Bring two corners together and fold in half again into a cone shape. 
  3. Put your finger in between the third and fourth layer and open up the cone, so it sits neatly inside the glass beaker. There will be a bit of paper higher than the glass.
  4. Ensure the side of the paper cone with three layers sits against the grooved side of the brewer, with the single layer on the opposite side of the beaker.
  5. The grooved side acts as a vent and keeps the filter paper cone from collapsing.

Half Moon

Folding the half-moon is very similar to the circle shape filter with fewer steps. The difference is the tab that you must fold up. 

  1. Bring corner to corner and fold the half-moon in half, just like you did in step 2 of the circle folding. 
  2. Fold up the tab sticking out.
  3. Bring the corners together again, so the tab is now inside the cone
  4. Open the cone between the third and fourth layer, just like you did with the circle filter

Square – Traditional

The traditional square filter comes folded in quarters in a shape that will look very familiar if you’ve folded either the circle shape filter or the half-moon shape. 

  1. Take the quartered filter, open it between the third and fourth layer
  2. Place it in the beaker, point side down, so the three-layer side is against the grooved edge of the cone with the single layer of paper opposite. 

Coffee lovers value this shape because of how easy it is to pull out the filter. The extra paper on the sides provides little handles to pick it up for easy disposal of the wet filter and spent coffee grounds.

Square – The Barista method

If you’ve ordered Chemex coffee at a coffee shop and watched them prepare it, you’ll see the filters are folded differently than the traditional square method. 

Here is how the baristas do it. It’s a little more complicated, but some say it gives a more balanced extraction from the ground coffee because no side of the filter is thicker than the others. 

It’s also prettier.

We suggest practicing this fold with a piece of paper before folding a filter. 

  1. Take the filter already folded into quarters.
  2. One corner will have more folds than the others. That point becomes the bottom point the water and coffee will drain through. 
  3. With the point closest to you, picture (or if you’re practicing, use a pen and draw) a line that goes from the bottom point to the top point across from it. 
  4. Now you have two triangles that make a diamond separated down the middle by the imaginary line. 
  5. Bring the side point to the imaginary line and fold.
  6. Flip the filter over so that the fold is against the table. Do the same fold on the other side. 
  7. Unfold it and lay it flat. 
  8. One of the folds is backward, but that’s OK because we have one more step to fix it. 
  9. Fold the filter in half.
  10. Thanks to the folds, you can place the filter into the Chemex, and when it unfolds, it stays up on its own. 
  11. Adjust if necessary, so no grounds slide through.
  12.  Congratulations! Now your coffee setup will look just like a barista’s. 

Final Thoughts

Folding Chemex filters can be very simple or complicated depending on which method you choose, just like pour-over methods. Take time to experiment and try new things and search for that perfect cup of morning coffee.

If Chemex isn’t suitable for you or you want to try something else that involves a similar method, we compared Chemex with other pour-over methods

Happy Caffeinating (and folding)!

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