A Chemex is a way of brewing coffee that is one part art, one part science, two parts swank. The hand-blown glass brewer was invented in the early 1940s by a chemist who wanted to create a method for making coffee that was both sleek and effective. At first glance, you might think this was a flower vase.
But the Chemex's thick paper filter and Jessica Rabbit-esque figure are designed to brew a clean, articulate cup of coffee. In recent years, specialty coffee folk have rediscovered this beautiful brewer. Its functional beauty has allowed it to stand the test of time; it serves as a visual representation of transparency and cleanliness of both cafe and coffee.
Bonus story: legend has it that Dr. Peter Schlumbohm, the likely mad scientist slash total baller who invented the device, drove a Cadillac with a little gold Chemex hood ornament.
See also: Cartel's Drew Scharnitzke Demonstrates 3 Coffee Brewing Methods
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.
Now, the process:
1. Chemex filters are four ply. Open the filter so that it forms a cone shape, with three sheets on one side and one sheet on the other. Place the filter in the Chemex so that the three-sheet thick side is by the spout.
2. Wet the filter with very hot water. This will help to remove any papery flavors, will warm the body of the brewer, and will help form a seal between the filter and the Chemex. Make sure you dump the water out after you rinse.
3. Add ground coffee to the dampened filter. Gently settle the coffee so that it forms a flat bed. At this stage, Jenny dug a little hole in the bed of grounds, about the size of a quarter, and maybe a quarter inch deep.
4. Start timer and add about 80 grams of water to the coffee bed, evenly saturating the grounds. If you're not using a scale, no worries - just add enough water to saturate the bed of coffee without having too much drip through the filter. If your coffee is fresh, you will see it bubble up at this point. This process is called "blooming." As a result of the roast process, coffee steadily releases carbon dioxide gas. This gas can contribute some strange or icky flavors to the cup. Blooming the coffee prior to brewing helps to quell the ick. Allow the coffee to bloom for about 30 seconds.
5. Start your pour! Jenny pours slowly, starting with a thin stream of water in the center, and gradually working her way out in slow, concentric circles. This prolongs the amount of time that the coffee and the water have to hang out, and allows time for all of the delicious compounds in the coffee to dissolve into the water. Brewing a Chemex takes patience! Cartel aims for a total brew time (with bloom) of about four minutes and fifteen seconds. That's alright - the finished product is worth the wait.
