A Guide to the CHEMEX

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May 27, 2022

Background

The CHEMEX coffee maker was invented in 1941 by chemist Dr. Peter Schlumbohm. He invented over 300 patents with a focus on making everyday objects more functional, attractive and enjoyable to use. His knowledge of coffee extraction led him to invent the double bonded CHEMEX paper filters for a perfect extraction every time. Schlumbohm’s inspiration for the carafe was the Bauhaus school of design and non-porous labware that would impart no flavor of its own. Using these elements he fashioned the iconic hourglass shape that has now become a part of American history. Made from a single piece of borosilicate glass and adorned with a wooden collar and rawhide tie, the CHEMEX is pure in both form and function. The CHEMEX can be found in the museums throughout the world and included in the permanent collection at the Brooklyn Museum, Corning Museum of Glass and MOMA, NY.

What you'll need:

- CHEMEX filters
- CHEMEX carafe
- Kettle
- Grinder 
- Digital scale
- Timer

Step 1

Weigh out the coffee (48g) and grind to a coarseness resembling sea salt.

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Step 2

Unfold your filter and place it in your CHEMEX, ensuring that the triple-fold portion is facing the pour spout and lays across without obstructing it.

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Step 3

Fully saturate the filter and warm the vessel with hot water. Discard this water through the pour spout.

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Step 4

Pour ground coffee into the filter and give it a gentle shake. This will flatten the bed, allowing for a more-even pour.

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Step 5

There will be four pours in total, and this is the first.

Starting at the bed’s center, gently pour twice the amount of water that you have coffee into your grounds (for example, 50g of water if you have 25g of coffee). Work your way gently outward, and avoid pouring down the sides of the filter. You’ll notice that adding this amount of water causes the coffee to expand, or “bloom.” Allow it to do so for 45-55 seconds. A solid bloom ensures even saturation.

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Step 6

Pour water in a circular pattern starting at the center. Spiral out toward the edge of the coffee bed before spiraling back toward the middle. Avoid pouring on the filter. Allow the water to drip through the grounds until the bed drops about 1 inch. You should use about 200g of water for this pour.

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Step 7

Repeat the same pour pattern as in Step 6, adding water in 200g increments. Repeat once more allowing the water to percolate through the grounds until the coffee bed drops about 1 inch before beginning the next pour.

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Step 8

Allow the water to drip through the grounds entirely.

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Step 9

The brew should have taken between 3.5 - 4.5 minutes. If the brew was too fast, consider using a finer grind or a slower pour-rate next time. If the brew was too slow, consider using a coarser grind or a faster pour-rate.

Step 10

Remove the filter and pour coffee into a warm mug or cup. Enjoy <3

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