The Chemex is iconic. Featured in the MOMA, Smithsonian, and on many of our kitchen counters, the Chemex is also our Director of Coffee's brew method of choice. I met up with Eden Marie to talk cup quality, quirky inventors, and how to brew the perfect Chemex cup.
Jess Bernhart: Why is the Chemex your favorite brew method?
Eden Marie Abramowicz: The Chemex achieves a fuller flavor. With this method, the coffee and water have a lot of time to hang out together, which we call "contact time." But on the flipside, because the Chemex has a thicker paper filter, the resulting cup is really clean – there's less sediment and particulate getting through to the cup. It's a balance of a full extraction and a very clean mouthfeel.
JB: And the Chemex is famous for its design. Can you tell us about its history?
EA: The Chemex was invented in 1939 by a German gentleman named Peter Schlumbohm. Schlumbohm was kind of a bachelor inventor. The Chemex was his most successful invention, but some of his other patents include weird cocktail shakers, lighting systems, and anything that would help his bachelor lifestyle – things that were aesthetically pleasing but also functional. He sold patents for vacuum bottles to Thermos, he tried patenting dry-ice. Schlumbohm came from a chemistry background, so the Chemex, in addition to being appreciated for its design aesthetics, also has nuances of function. You'll notice it has a spout that we pour out of, but that spout also serves a function during brewing. The air in the bottom bowl needs to be displaced for the coffee water to drop through.
JB: Otherwise it creates a vacuum?
EA: Exactly. With most brewing methods, the air can easily escape from all over. If you picture a v60 or typical pourover, they have ridges, which means the air can escape easily all around. With the Chemex, the only way air can escape is through the spout. That increases the dwell time, because it's harder for air to escape through this tiny little passageway, which adds to that long extraction time and full body.
JB: And you use your Chemex every morning, right?
EA: Yes, it’s a favorite ritual.
JB: Are there coffees that you think brew best on a Chemex?
EA: That's really a matter of personal preference, but I usually brew lighter bodied, fruit-forward coffees on the Chemex, as it amplifies those attributes. Petunias is one of my favorites to pour over, and I always have some on hand.
6 Steps to the Perfect Chemex Cup
What you’ll need:
Hot water just off the boil (about 205°F), ideally in a gooseneck kettle
Scale (optional but recommended)
Total time: less than 5 minutes
Step 1: Prep and pre-wet
EA: First, set the Chemex on top of your scale. Unfold the filter and place it in the top of the vessel, making sure the three-layered side of the filter is lined up with the spout. Next, pre-wet the filter using the same temperature water (205°) that you’ll be using for the brew. To get your water at 205°, bring it to a boil and then let it sit for about 30 seconds.
JB: Why do you pre-wet the filter?
EA: Pre-wetting preheats your brewing vessel so that the water and vessel stay up to temperature, and your coffee will stay a little bit warmer. It also gets rid of the paper taste in the filter. This is particularly important with Chemex filters, which are 30-40% thicker than the average paper filter. If you're curious, you can try drinking your pre-wet water. You’ll notice it has a kind of fibrous, papery taste to it.
EA: It's also important to remember after pre-wetting to dump the pre-wet water, otherwise you will definitely get to taste that paper flavor.
Step 2: Grind your coffee
EA: For a single cup, weigh out 20g of coffee and grind it to the consistency of kosher salt. You can fine-tune your grind size over time, but a good starting point is to grind it a little coarser than you would for a Mr. Coffee, but finer than a French Press. Now you’ll dump the ground coffee into the base of the pre-wet filter. Shake it a little bit so that it's an even, flat bed of coffee.
Step 3: The bloom
EA: Tare your scale so that it reads “0” before the first pour. The first pour is called "the bloom." Especially with freshly roasted coffee, there's a lot of gas trapped in there. You'll notice when you add a little water that the coffee actually swells and you'll see some bubbly action. This is the coffee de-gassing. To figure out how much water to use for the bloom, just double the weight of the dry coffee that you started with. Since I started with 20g of coffee, I'm going to pour 40g of water for the bloom. I'm going to start my timer right away, too. We're going to let this sit for 30 seconds, priming all those coffee particles to impart their tastiness.
JB: Is there anything you can learn about the coffee in this phase?
EA: The biggest thing is you want to see those bubbles and that action. Otherwise, your coffee might be a little stale.
Step 4: Second pulse
EA: When your timer reaches 30 seconds, start the second pulse. This is just a slow and consistent pour. If you can, pour in a gentle spiral, avoiding pouring directly into the middle or around the edges of the filter. Pour until you reach 150 g of water – you want this pour to end at around 50 seconds.
Step 5: Third pulse
EA: Give that second pulse a moment to brew, waiting until it has almost filtered through, but not entirely – there should still be water in the bed. Now for the third pulse, starting around 1’10, go all the way up to 320g of water. We'll let this brew for another thirty seconds or so, til it's through. And then we're done.
JB: What is an ideal overall brew time?
EA: 3'20 to 3'40 is what you want to aim for. If you're missing that mark by a lot, reassess your grind size. If it’s taking too long, your grind is a little too fine. And if it’s rushing through the coffee, your grind may be too coarse.
Step 6: Toss the filter, pour, and enjoy