We prefer a 15:1 (water:coffee) ratio with the Chemex Brewer. The Chemex is for the most part a multi cup brewer so our batch sizes will be bigger than our general brewing guide.
We will use a 40 gram dose of ground coffee and 600 grams of hot water.
The Chemex filter is unusual and has three leafs of paper on one side and one on the other. Always keep the three leaf part of the filter toward the pour spout of the Chemex. If the thinner side is placed on the spout side it can sometimes form a seal in the spout and stop the brewer from dripping as efficiently.
Step 1: Boil your water and rinse the filter thoroughly, it is very thick paper and can impart a papery flavor to the coffee if not rinsed well. Always pour out the rinse water after rinsing!!
Step 2: Once rinsed, add your coffee grinds to the filter. You will want a slightly coarser grind setting than used in our general brewing guide (kosher salt).
Step 3: Next, make a small well in the center of the coffee grinds in order to saturate the coffee grinds evenly. Start by making a pour of 80 grams to bloom the coffee, swirl the slurry (coffee/water mixture) a few times then let sit for 45 seconds.
Step 4: Make your next pour until you reach a total of 450 grams of water and swirl the slurry gently to level the coffee bed.
Step 5: Then add the final 150 grams of water slowly and allow the brew to drip out.
Step 6: This process will take a range of different times depending on grind setting, the Chemex is also a slower brewer so any time between 5-7 minutes in total brew time could be delicious, it will be up to you to adjust to taste. If the brew is too weak or drips out too fast for you try making your grind setting finer. If it is too strong or drips out to slowly make your grind setting more coarse.
Brewing filter coffee is a matter of preference and this is just meant to be a starting point, remember that coffee is subjective, what tastes good to you is what matters so experiment with these variables to dial in what tastes best to you!