How to Brew a Chemex

The Chemex coffeemaker was invented by Peter J. Schlumbohm, a doctor of Chemistry, in 1941. He applied his knowledge of laboratory apparatus and methods of filtration when designing the Chemex. The key to the Chemex method is the Chemex-Bonded filters which are 20 to 30 percent heavier than typical coffee filters and only extract the desirable parts of the coffee bean. The filter combines a very fine grain, required for holding back coffee sediment; with the right filtration speed (not too slow, not too fast) that promotes proper infusion. The filter is designed not to burst under the weight of the liquid during infusion and not to break when lifting out the grinds.

Tools:

-Spring water or filtered water
-195-205 F water temperature
-A burr grinder
-Scale
-Timer (to help control brew time)
-Freshly roasted whole bean coffee (2-14 days max), stored at room temperature in an airtight  container. Grind right before use.
-Filter. There are bleached and unbleached paper Chemex filters. These filters allow for a clean  cup and help maintain the brewing time. Various after-market metal filters are available. They  allow for more body by way of oils and coffee particulates.
 
Brewing:
-Open the Chemex-Bonded Coffee Filter into a cone. One side should have 3 layers, the other  side 1 layer. Place the cone in the top of the Chemex with the layers toward the pouring spout  (this will allow air to escape during the brew process). Rinse filter thoroughly with 100g hot  water to avoid a starchy paper taste and to heat the device. Invert Chemex with filter to drain.
-Grind 50 grams of coffee on medium coarse (Kosher salt).
-Tare scale with Chemex, filter and grounds. 
-Pour 100 grams of water over all the grounds.
-After 30 seconds, pour water in a spiral from the center up to 300 grams. Every 30 seconds, pour 100g after that (@1:00 400g, @1:30 500g, @2:00 600g).
-Never let it go dry. Avoid pouring on/down the sides.
-Repeat until you reach 700 grams. 
-Total brewing time should be 4:00 minutes. 
-Change the grind finer if under and coarser if over. 

Repeat and enjoy!

 

Tips for a better Chemex:

  • Finding the proper grind: If your grind is correct, the whole brewing process should take approximately 4 minutes. If it pours through too fast, and the resulting coffee is weak, then the grind is too coarse. If it pours too slowly and the resulting coffee takes longer, the grind is too fine. Adjust as necessary according to the amount of time it takes you to finish brewing.
  • A trick to pouring is to start in the center and pour in a circular motion outward, causing the dark brown grinds to turn a tan color until most of the dark brown is not visible. Let drain and repeat. This way you know you have an even extraction and are not over extracting only one part.
  • Do not let the grinds go dry during the brew process or the temperature of the grounds will fall below your proper brewing temperature.
  • Do not pass too much water through the grounds or you will have weak coffee with over-infused bitter components, otherwise known as over extracted coffee.

>>Print or download Chemex recipe card