The Chemex coffee maker was invented by chemist Dr. Peter Schlumbohm in 1941. Its iconic hourglass-shape of non-porous borosilicate glass and wooden collar is recognized as “one of the best-designed products of modern times”. The CHEMEX® can be found in museums throughout the world and is included in the permanent collection at the Brooklyn Museum, Corning Museum of Glass and Museum of Modern Art in New York City.
While the classic series Chemex carafes brew perfect coffee as well, we use a 5 cup handblown Chemex carafe of functional beauty – from the borosilicate glass to the polished wood collar with leather tie.
Step 1: Get into the grind
Grind your favorite whole bean coffee (some exceptional whole beans are available from Endless Mountains Roastery) to a medium coarse grind – approximately the consistency of Kosher salt.
It’s best to use a burr grinder to deliver a more consistent particle size, allowing for a more consistent extraction and fuller bodied cup of coffee.
Step 2: Filter up
Open a Chemex filter into a cone shape so that one side of the cone has 3 layers, and place it into the top of the brewer. The thick three-layer portion should cover the pouring spout.
Dampen the filter with warm water to rise and preheat the brewer. Drain the water through the filter completely, pour water out of the brewer while keeping the filter sealed against the coffeemaker well.
Step 3: The scoop
Coffee is best extracted using a ratio of 1:16.6 – one part ground coffee for 16.6 parts of water. We typically get our day started using 43 grams of ground coffee with 720 ml of water — this roughly translates to one rounded tablespoon of ground coffee for every 5 oz. cup. Simply add your ground coffee to the filter cone.
On all Chemex brewers except the pint size model , the “button” indicates the carafe is half filled and the bottom of the wooden collar/spout indicates it’s full. On the pint size model the button is the full marker.
Step 4: Let it bloom
Once you have brought the water to 96 degree Celsius (205 degree Fahrenheit), you are ready to begin your pour. Pour 86 ml of water (twice the volume of ground coffee) in a circular motion over the coffee grounds to wet them, and wait for about 30 seconds for them to “bloom”.
The “bloom” is escaping gas that has been trapped in the beans during the roasting process. You will see the grounds inflate and bubbles appear on their surface as the flavor inhibiting gas expels upward. Once this is complete, water can freely extract the aromatics and coffee oils while brewing.
Step 5: First pour
After the grounds bloom, slowly pour to half of your water, 360 ml, over the grounds while keeping the water level well below the top of the filter (quarter inch or more).
Step 6: Brew on
After two and one half minutes, slowly pour the remaining 360 ml of water over the grounds, using a circular or back-and-forth motion as you pour to ensure an even saturation of the coffee.
Step 7: Toss the filter
At approximately the 4:30 minute mark, your extraction will be complete. Lift the filter with the spent ground out of the brewer and discard. If all of your water moves through the filter at a faster rate, you grind is likely too coarse. Conversely, if your extraction moves through the filter at a slower rate, your grind is likely too fine.
Step 8: Savor the perfect cup
Pour your freshly made coffee into your favorite mug and indulge in the flavor.