How to Fold Chemex Filters

By Admin February 1, 2022

The famous Chemex coffee maker was created in 1941 by Peter Schlumbohm. This small gadget is well-known for its sleek look and the clean coffee it produces due to its design and the filters it uses. 

Why makes Chemex filters special?  

Well, they are 30% thicker than their traditional counterparts. Its heaviness eliminates unwanted oils, resulting in a flavorful cup minus the bitterness or sediment. 

You can purchase Chemex unfolded filters in 3 shapes: square, circle, and half-moon. Here, we’ll go over how to fold Chemex filters depending on the shape you have. Let’s dive in!

Circle Folding Instructions 

  1. Fold the circle in half. 
  2. Bring both corners together and fold in half once more. You should have a cone shape.
  3. Place your finger in between the 3rd and 4th layer and open up the cone. At this point, it should sit neatly inside the glass beaker. 
  4. Make sure the side of the cone with the three layers sits against the grooved side of the brewer. The single layer should be on the opposite side of the beaker.
  5. The grooved side acts as a vent. It keeps the filter cone from collapsing.

Half Moon Folding Instructions

The half moon Chemex filter folding instructions are similar to the circle one. The difference is that with the half moon filter, there is a tab that you must fold upwards. 

Follow these steps: 

  1. Bring the two corners together and fold the half-moon in half. 
  2. See the tab that sticks out? Fold it up. 
  3. Bring the corners together again. The tab should now be inside the cone. 
  4. Open up the cone between the 3rd and 4th layer (just like you did with the circle filter). 

Traditional Square Filter Folding Instructions

Next up is how to fold chemex square filters. The square shape is the traditional filter. It comes folded in quarters. This shape should look familiar if you’ve ever folded either the half-moon or the circle shape filter. 

  1. Take the quartered filter and open it between the 3rd and 4th layer. 
  2. Place it in the glass beaker with the pointy side facing down. The three-layer side should be against the grooved edge of the cone with the single layer of paper laying opposite. 

Barista Square Filter Folding Instructions

If you order some Chemex coffee at your local cafe, you’ll notice that they prepare the filters differently. 

They fold square Chemex filters differently than the traditional square folding method. Their process is a bit more complicated; however, they claim it offers a more balanced coffee extraction since no side of the filter is thicker than the others. It also looks prettier if we say so ourselves! 

Here are the instructions to fold a square filter, the barista way. 

  1. Take the filter. It should already be folded into quarters.
  2. One corner will have more folds than the others.This is the point that the water and coffee drain through (it’s the bottom point).
  3. Take the point closest to you and picture a line that goes from the bottom point all the way to the top point across from it. You should have two triangles that make a diamond. These triangles are separated down the middle by the imaginary line you created.
  4. Bring the side point to this imaginary line and fold. 
  5. Flip the filter over and do the same to the other side.
  6. Unfold, lay it flat, and then fold the filter in half. 
  7. Place the filter into your Chemex. It will stay up on its own once it unfolds. Adjust as necessary so no grounds accidentally slide through. 


What is the difference between the circle and square filter?

Both circle and square Chemex filters are made the same way. The difference is the shape and aesthetics. Some like how circle filters look better while others prefer square when it comes to looks.

What’s the difference between brown filters and white filters?

The paper is the same. The difference lies in that the white filter paper undergoes an oxidizing cleansing bath and then a series of hot water baths. The brown paper undergoes the hot water bath only, hence why it retains its natural color. 

The Takeaway

Chemex filter folding can be very simple or very complicated depending on the method you use. Take the time to practice and experiment with different shapes until you find the technique that gives you that perfect morning cup of joe.