Chemex

The Chemex is a pour-over coffeemaker made from one piece of glass, shaped like an hourglass, with a wooden collar tied on with a leather thong. You brew straight into it through a thick paper filter, which gives one of the cleanest, lightest cups of any brewer. It was invented by the chemist Peter Schlumbohm in 1941, and a 1941 Chemex sits in the Museum of Modern Art’s collection. Here’s how to brew a great pot, how to fold the filter and which size to get.

The short version

• Glass pour-over that brews several cups straight into its own body.
• Thick bonded paper filters give a very clean, light cup.
• Grind medium-coarse, about like kosher salt.
• A good recipe: 45 g coffee, 750 g water at about 93°C, poured in stages (Counter Culture Coffee).
• Three-layer side of the filter to the spout.

What makes the Chemex different?

Most pour-overs sit on top of a mug. The Chemex is brewer and carafe in one: the top half holds the filter, the bottom half collects the coffee, and the wooden collar is the handle.

The big difference is the filter. Chemex’s own bonded paper filters are thicker than most pour-over filters. They slow the water down and hold back more of the coffee’s oils and fine particles, so the cup is very clean and light-bodied, with little sediment. If you like a heavier, richer coffee, a French press is the opposite end of the scale.

What do you need to brew with a Chemex?

• A Chemex and Chemex filters
• Coffee and a burr grinder
• Scales, so you can weigh coffee and water
• A kettle; a gooseneck makes slow, steady pouring easier

How much coffee and water should I use?

This is Counter Culture Coffee’s Chemex recipe, which makes two 12 oz cups:

	Amount
Coffee	45 g, ground medium-coarse
Water	750 g, at about 93°C (200°F)
Ratio	1:17
Bloom	100 g of water

Many roasters use a slightly stronger 1:16. Chemex’s own instructions go by volume instead: one rounded tablespoon of ground coffee for every 5 oz cup, or more if you like it stronger.

What grind size is best for a Chemex?

Medium-coarse, about like kosher salt. That’s coarser than most V60 recipes, because the thick filter already slows the water down. If your brew takes much longer than about 5 minutes, or tastes bitter, grind coarser. If it’s quick, sour and thin, grind finer.

How do you brew a Chemex, step by step?

1. Fold the filter into a cone with three layers on one side and one on the other. Seat it with the three-layer side against the spout.
2. Rinse it with hot water to warm the glass, then pour the water out through the spout, leaving the filter in place.
3. Add 45 g of coffee, ground medium-coarse, and shake it level.
4. Bloom: start a timer and pour 100 g of water at about 93°C to wet all the grounds.
5. At 30 seconds, pour in a slow circle to 200 g.
6. At 1 minute, or once the level has dropped about a centimetre, pour to 300 g.
7. Keep going every 30 seconds, or each time it drops about a centimetre, until you reach 750 g. Let it drain.
8. Lift out the filter, swirl and pour, holding the Chemex by its collar.

Brew mode on this page times each pour for you.

Which way does the Chemex filter go?

Chemex filters fold into a cone with three layers on one side and one on the other. The three-layer side goes against the pouring spout, as Chemex and most brew guides say.

Chemex makes its bonded filters as pre-folded squares and circles, in white and natural. Squares don’t fit the smallest 3-cup models, so check the box for your size.

Which size Chemex should I buy?

Chemex counts in 5 oz “cups”, so its sizes are smaller than they sound. The Classic Series comes in:

Size	Holds
3-cup	15 oz
6-cup	30 oz
8-cup	40 oz
10-cup	50 oz

Chemex calls the little glass button on the body the “bellybutton”: it marks half full on the 5- to 10-cup sizes, and full on the 3-cup. For one or two people I’d go for the 6-cup: the 750 g recipe above fits in it.

Chemex vs other brewing methods

	Chemex	V60	French press
Type	Pour-over	Pour-over	Immersion
Filter	Thick bonded paper	Thinner paper	Metal mesh
Grind	Medium-coarse	Medium-fine	Coarse
Cup	Very clean, light	Clean, bright	Heavy, full
Brews into	Its own glass body	A mug or server	Its own jug

How do you clean a Chemex?

Lift the filter and grounds out and throw them away. To wash the glass, take the wooden collar off first by untying the leather tie. Wipe the collar with a damp cloth rather than soaking it. Then wash the glass as the care instructions for your model say.

General guidance only. The Chemex is glass, so handle it with care when hot and let it cool before washing. Always follow the instructions that come with yours.

A short history of the Chemex

• 1941: Peter Schlumbohm, a German-born chemist working in New York, designs and patents the Chemex. He borrowed from laboratory glassware, with a glass funnel and flask in one piece.
• 1958: designers at the Illinois Institute of Technology select the Chemex as “one of the best-designed products of modern times”, Wikipedia records. The Museum of Modern Art in New York holds a 1941 Chemex in its collection, and Chemex says Schlumbohm took inspiration from the Bauhaus and from laboratory glassware. Over his career, Chemex says, he developed more than 300 patents.
• Today: the Chemex Corporation makes it in Chicopee, Massachusetts.

You’ll often read that Macy’s launched the Chemex after Schlumbohm handed a buyer a sample. It may be true, but I haven’t found a primary source for it, so take it as a good story rather than settled fact.

Chemex models and variations

The Classic Series is the Chemex this page covers. Chemex also makes:

• Glass Handle: a glass handle instead of the wooden collar.
• Handblown: blown by hand in small batches, in 3, 5, 8 and 13-cup sizes.
• ChemAer: an 8-cup Chemex with paddles inside that aerate the coffee as you swirl.
• Funnex: a single-cup dripper that sits on your mug.
• Ottomatic: an electric brewer that pours over a Chemex for you.

Chemex vs other brewers

• V60: a single-cup pour-over with a finer grind and a brighter cup.
• Japanese iced coffee: pour-over brewed onto ice; the Chemex works well for it.
• French press: the full-bodied opposite of a Chemex.
• Kalita Wave and Melitta: other classic pour-over brewers.

Explore every pour-over in the pour-over chapter.