In brief
A Chemex is a pour-over brewer made from one piece of glass, shaped like an hourglass. The top holds a paper filter and the bottom collects the coffee. A wooden collar tied with a leather thong lets you hold it when hot.
Its filters are what set it apart. They are thicker than ordinary drip filters, and Wikipedia says they remove most of the coffee oils. The result is a very clean, light-bodied cup.
Those thick filters also slow the flow. That is why the Chemex usually calls for a coarser grind than other pour-over cones.
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Who invented the Chemex?
Peter Schlumbohm, a German chemist, designed it in 1941. Perfect Daily Grind says he was inspired by two pieces of lab glass: a glass funnel and an Erlenmeyer flask. He added an air channel and a small bump, sometimes called the belly button.
The design has become a museum piece. Wikipedia notes that in 1958, designers at the Illinois Institute of Technology named it one of the best-designed products of modern times. It is in the collection of the Museum of Modern Art in New York.
Wikipedia says the Chemex Corporation makes it in Chicopee, Massachusetts. According to Chemex, the Classic Series comes in 3, 6, 8 and 10 cup sizes, from 15 to 50 ounces.
Why does Chemex coffee taste so clean?
Mostly because of the filter. Chemex's bonded paper filters are heavier than most. Perfect Daily Grind puts the difference at 20 to 30 percent heavier than other filters.
Wikipedia says the thicker paper makes coffee much cleaner than many other systems. The tradeoff is body. With fewer oils in the cup, a Chemex tastes lighter in the mouth.
How you fold the filter matters too. Chemex says to open it so one side has three layers, with that thick side over the pouring spout.
What grind size does a Chemex need?
Medium-coarse. Chemex's own instructions say to grind to a medium coarse ground. Counter Culture also lists the Chemex as medium-coarse, like kosher salt.
That is coarser than Counter Culture's medium grind for a V60 or Kalita Wave. Perfect Daily Grind describes the target as slightly finer than French press, like granules rather than sand.
Grinder choice shows up here. Baratza, for example, suggests setting 25 on the Encore for its Chemex recipe. See the Baratza Encore settings, or translate a recipe to your own grinder with the grind converter.
How much coffee does a Chemex use?
It depends on the recipe and the size of brewer. Chemex's own guidance is one rounded tablespoon of ground coffee per 5 oz cup. Roasters' recipes weigh it instead.
| Source | Coffee | Water | Ratio |
|---|---|---|---|
| Baratza | 50 g | 800 g | 1:16 |
| Stumptown | 42 g | About 700 g | About 1:17 |
| Chemex | 1 rounded tbsp | Per 5 oz cup | By volume |
Baratza aims for a total brew time near five minutes. Perfect Daily Grind gives three to five minutes, depending on grind and pouring. The brew ratio page explains how to scale these.
How is a Chemex different from a V60?
Both are pour-over cones, but the filter and the grind differ. The Chemex uses thick bonded paper and a medium-coarse grind. A V60 uses thinner paper and, per Counter Culture, a medium grind.
The Chemex also comes in sizes up to 50 ounces, so it suits brewing for several people. Our Chemex vs V60 comparison covers the differences in detail.
Does a Chemex need a bloom?
Yes, like most pour-over methods. Chemex tells you to wet the grounds with a little water and wait about 30 seconds for them to bloom. Baratza uses 100 g of water on a 50 g dose for its bloom.
For the full method, from rinsing the filter to the final pour, see the Chemex brewing guide.
Sources
- Wikipedia: Chemex Coffeemaker
- Chemex: Classic Series info and support
- Perfect Daily Grind: Chemex, the history and brewing guide
- Baratza: Chemex brew guide
- Counter Culture Coffee: Coffee basics, grind size
- Stumptown Coffee: How to perfect your pour over coffee
By Jeff Gluck · Checked Oct 21, 2026