The Chemex, invented all the way back in 1941, is known for its extremely clean brews due to the extra-thick proprietary filter. While a gooseneck kettle helps control the flow of water, this brew method is ultimately quite forgiving as long as the grind size is kept in check.
For 2 cups:
36 grams medium/fine ground coffee
600 grams (ml) water at 200°F
3:40 – 4:20 brew time
Weigh the Coffee
Using a scale, measure out 36 grams of coffee for a four cup brew. If making six cups, use 54 grams instead.
Grind Coffee and Prepare Water
Grind the coffee a little coarser than you would for a drip pot or V60. On a Baratza Encore or Virtuoso, we like to use a setting of around 18. If using more or less coffee, you may need to adjust the grind (finer for less coffee, coarser for more coffee).
Meanwhile. heat your kettle (gooseneck style is best, but any will work) to 200°F. If heating on the stove, heat to boiling and let cool for 40-60 seconds.
Prepare the Filter
Open the filter so that the bulk of the paper is on one side, and one layer of paper is on the opposite side. Place the filter into the Chemex so that the side containing the thick paper is centered on the pour spout. Placing the filter this way is vital to allow airflow. Lack of airflow could cause your brew to get stuck or take too long, leading to over-extraction and bitter flavors.
Pre-wet the Filter
Pour hot water onto the dry filter, making sure to wet the entire surface. If you have enough hot water prepared, wash the filter liberally to make sure all the paper taste is washed out. Once done, pour the water out through the spout. Pre-wetting the filter is more important when using brown, non-bleached filters, but is a good practice for any method using paper filters.
Add Coffee and Level the Grounds
Pour your ground coffee into the filter, and shake the brewer side-to-side to create a level bed of coffee. Place the brewer on your scale and tare/zero the scale.
Bloom for 30-40 seconds
Pour just enough water to cover all the grounds, no more than 120g water in about 20 seconds, and wait 30-40 seconds. When finished, your scale should read around 120g and 1m:00s.
This part of the brew process is called the “bloom” due to the fun dome of coffee and bubbles that appear when the hot water comes into contact with fresh coffee. This occurs due to a relatively large amount of carbon dioxide within the ground coffee being released when the brewing process begins.
Begin Initial Pour
Point your kettle spout at the center of the brewer and begin making small, slow concentric circles with water. Slowly increase the diameter of your circles to move out and cover the rest of the coffee. Pour around 220g of water in 25 seconds and wait up to 45 seconds for the water to draw down. By the end of this step, your scale should be near 340g and 2m:00s.
Begin Second Pour
Starting in the center of the coffee bed, pour another 260g over 30 seconds. This should bring your total weight up to 600g, and the coffee should finish dripping by 4m:20s.
Pour and Enjoy!
Remove the grounds and filter and dispose (they can go straight in the compost!). Hold the wooden collar, because the glass is very hot, and pour into your favorite mug using the spout on the Chemex. You should have enough left in the vessel to share with a friend, too. Enjoy!