CHEMEX Brewing Guide
STEP ONE: This will vary with your personal preferences and the type of coffee, but as a starting point, we recommend 50 grams of coffee to 750 grams of water (this is a 1:15 ratio). Heat 800-grams of water; the extra water is for pre-rinsing the filter in step three.
GRIND: Medium-coarse, similar to sea salt, 50-grams of coffee beans.
Unfold the Chemex filter and place it in the Chemex with the triple-layered portion facing the pour spout.
Fully saturate the filter with hot water, discarding the water afterward.
Pour the grounds into the filter, shaking to flatten the coffee bed, allowing a more even pour-over.
Starting at the center of the coffee bed, pour twice the water that you have in coffee (the suggested 50 grams of coffee would use 25 grams for this step). You are working your way outward, avoiding pouring hot water on the filter. WAIT 40-55 seconds while the coffee blooms.
COOL FACT: The bloom is the process called "degassing." After roasting coffee, it gives off Carbon dioxide for the two weeks following roasting. After the beans are ground, the surface area increases, and the amount of gas being released increases(that's why we recommend grinding right before using). When you add water to the freshly ground coffee, the gas release increases, seen by all the bubbling. If you don't allow the coffee to bloom fully, it can release a sour flavor, and the gas repels water. Water extracts all the lovely coffee aromatics and oils, which only happens after the gas escapes.
With about 200 grams of water, pour the 205-degree water spiraling out from the center and then working your way back to the center. Wait until the coffee-water slurry drops about an inch before moving on to the next step.
Repeat the previous step, waiting until the grounds in the slurry drops. Repeat until the subscribed amount of water is used.
Allow all the water to drip through the coffee grounds. From when you started adding water to this point should be 3.5-4 minutes.
COFFEE / WATER CONTACT TIME: If it took longer than 3.5 to 4 minutes, consider using a coarser grind and a faster pour to allow the water to move faster. If your brew time was more than 4 minutes, use a finer grind and a slower pour time.