A Round Boy Roasters Brew Guide - Part 2 Chemex

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The Chemex

was invented by the Chemist Peter J. Schlumbohm, from Germany in 1943.  It never got traction with the masses till the 3rd Wave Coffee emerged in the 90s where taste profiles of coffee, lighter roast and more succinct aromas were more widespread and sort after. It is a beautiful, elegant work of art that brews clean crisps coffee that still retains all its clarity of flavours.

Essentially, the main factors that make the Chemex such an amazing brew gadget are these:

  1. The filter paper is thick and is roughly 20% thicker and heavier that its other counterparts and thus allows for more unwanted oils from the coffee being brewed to be kept out of the final cup.
  2. It consists of a singular opening in the centre, smaller than the V60, of the apparatus which allows for water to flow down evenly and at a slower rate, into base allowing for aeration of coffee which in turn allows for more complexity of the coffee to showcase.



Roundboy Method - Here we are using 20 grams of coffee with a ratio of 1:15 so the end yield would be 300 grams of brewed coffee.

Things you will need:  (a) 1-3cup Chemex (b) Chemex Filter Paper (c) Thermometer (d) Scale and timer.  (e) Gooseneck kettle (f) Filtered water boiled between 90-94 degrees (g) Coffee (medium to coarse grind)


Step 1 Place the Chemex over a scale and place the filter paper into the apparatus. Folding the filter paper correctly is important and can be tricky but practice makes perfect. Rinse the filter paper thoroughly to remove any excess paper taste that might contaminate the coffee. This primes the filter paper for coffee extraction and at the same time preheats the Chemex. Remove any excess water from the Chemex.

Step 3 Place 20 grams of medium ground coffee in the middle of the Chemex filter paper. Give it a light tap to even the grounds out more.

Step 4 Using the gooseneck kettle and with desired temperature of water at (g) wet the coffee grounds in the middle, in a slow controlled circular motion, using about 30 grams of water or where it just covers the ground coffee fully. Watch the coffee bloom. This bloom allows for the coffee grounds to soak in the water and release Co2 gases which would otherwise affect the final taste of the coffee. Once the bloom starts to flatten out which usually is around the 45 second mark, you’re ready for the main pour.

Step 5 For the main pour, pour the water in a controlled circular motion, from the center of the grounds in an outward spiral motion till the scale reaches 300g of water accounting for the amount of water used for pre-infusion of the coffee. Total brew time should take about 2min 00 secs – 2 min 30 secs. Decant the coffee into a preheated drinking vessel, sip and enjoy the crisps clean cup of coffee that oozes clarity. We dare say almost tea-like!


Move on to Part 3 for Aeropress method!