Cartel Coffee Lab barista Jenny Vaughn walked me through the process her shop uses to brew the perfect Chemex.
Let's start with the necessary materials:
-A Chemex Coffee brewer (Jenny used the six cup model)
-Chemex coffee filters
-A hot water kettle (it helps to have one with a long, skinny spout - you'll be better able to control the pour)
-A scale helps, but it's also negotiable (see below)
-A kitchen timer or stopwatch
-40 grams medium-ground coffee of your choosing (Jenny brewed up Cartel's Sihuamonta, El Salvador. Try it. It's great.) If you're doing this at home, and you don't happen to have a gram scale lying around, this translates to just under 3 tablespoons.
Generally speaking, coffee folk brew coffee with a ratio of 1 part coffee to between 15 and 17 parts water. Cartel uses a 1:16 ratio; feel free to play with the amount of coffee and see what works for you. You may want to adjust depending on the attributes of the coffee, how long ago it was roasted, and grind size, among other things.
This means that to follow Cartel's recipe, you will need:
-640 grams of water at about 210 degrees Farhenheit (just off a boil, in case you missed that day at school.) If you don't feel like weighing, no big deal. 640 grams of water is about 22.5 ounces.