The Chemex was invented by Peter J. Schlumbohm, Ph.D, in 1941. He received his doctorate in chemistry from the University of Berlin. We love that this chemist was so serious about coffee!
The following is how we brew 25 ounces of coffee (which is half of a 10-cup Chemex vessel).
Measure out 48 grams of fresh coffee. Grind to the consistency of coarse salt.
Heat the Chemex with hot or boiling water and discard.
Whether using a paper or stainless steel filter (we love the Kone for its consistent extraction and clean taste) prepare it before placing in the Chemex. If using paper, rinse the filter with hot water. If using a stainless Kone, prewet with boiling water. Discard water in Chemex.
Add ground coffee to the filter.
Place the Chemex on the scale and tare (we love the Hario digital scale).
Start a timer.
Watching the scale readout, add 100 grams of water to saturate the grounds and let the grinds bloom for 15-20 seconds. Make sure that your water temperature remains between 195-205 degrees Fahrenheit throughout the pour.
Slowly pour water evenly over the grounds keeping in mind that you are looking for a four-minute extraction with a total weight of 710 grams.
Remove the filter. (Letting it drip into the vessel will make the coffee bitter.)
Taking it over the finish line... For best results always use fresh coffee, filtered water, and a quality burr grinder. While it may sound complicated, we highly recommend using a timer and a scale with a tare so that every factor – coffee weight, water weight, pouring time – is consistent. This makes the process easy and eliminates guesswork so you’re always confident you can replicate yesterday’s brilliant cup.