Chemex: history and coffee extraction

I maestri della tostatura media
Chemex is a beautiful and fascinating brewing tool. It is one of the most popular coffee makers in the world of coffee lovers and also by designers.

The Chemex method, compared to the classic espresso, brings us to experience the coffee ritual in a different, more “slow” way. It is almost more like afternoon tea than coffee!

We have already told the story and the extraction of Mocha, Aeropress and French Press >> today I’m telling you about Chemex!

The history of Chemex

Unique and recognizable to anyone, it is an hourglass-shaped carafe made of glass, a nonporous material that is guaranteed not to absorb odors and flavors, thus leaving each extraction untouched. Its wooden rings, bound by a leather strap, are not only aesthetically pleasing but also allow for perfect grip without burning.

The shape of the carafe, similar to a wine decanter, allows oxygenation that allows aromas to develop and diffuse to their fullest.
The main feature is the thick and porous paper filter, which retains all the oils, giving us a clean and intensely aromatic cup.
Chemex was invented in 1941 by Peter J. Schlumbohm, a German chemist living in New York City.

In 1958, designers at the Illinois Institute of Technology felt that the Chemex was one of the best designed products in modern times, so that it was displayed and included in the permanent collection of the MoMa in New York.

All over the world there are fans who exchange tips on forums on how to get a perfect cup of coffee with this type of extraction.

The coffee maker starts from the smallest sizes of 1-3 cups, up to the 10-cup size, and prices range from €55 to €70.

The extraction with Chemex

Extraction with Chemex is simple and intuitive, but we need some tools:

  • Chemex
  • A dedicated paper filter
  • A brewing kettle
  • A scale
  • A timer

The Brew Ratio, or dose, is 60 g of coffee per 1 l of water; in this case, for one person, I will use 15 g of ground coffee per 250ml of water;

Coffee should be ground medium-large, similar to salt. To be precise, the grain size should be between 500 and 700 microns.

Steps for extraction:
  • Heat the water to around 95°C. Depending on the coffee you use, the temperature can change within a 92-96°C range and find out how you think it comes out best!
  • Insert the filter paper and wet it with hot water. In this way you remove both the paper notes that might affect the coffee aroma, and in the meantime you also warm the instrument;
  • Empty the instrument of water and pour out the mince. Give it a few taps on the side to level it out and create an even loaf;
  • Start with pre-infusion to prepare the coffee for extraction, wetting the entire ground coffee cake and flushing out any residual gas. The pre-infusion is done with twice as much water as coffee, so since we have 15g of coffee, we will pour 30g of water being careful to wet all the ground coffee;
  • Wait 30 seconds;
  • Now pour in the remaining part of the water, so 220ml, in a thin, continuous line. Pour it in circular motions, being careful not to hit the walls of the instrument, only the coffee, so the water will not run off the sides.
  • If you want to increase the extraction capacity and get a more intense coffee, just increase the spin, that is, the circular motion. Then take the instrument and rotate it, as you would a glass of red wine before smelling it!
  • The draw must end within 2 minutes. If it ends earlier it means that the coffee is ground too wide and therefore the water runs off too easily, but if it ends later then the coffee is ground too fine and the water will over-extrude.

The result of the resulting drink?

A long, intense coffee that expresses a wide aromatic range. Overall delicate, with total absence of bitterness, while enhancing acidity and sweetness.

It is perfect for a nice energizing wake-up call, or to sip leisurely while sitting comfortably at home or at a coffee shop.

The coffee I recommend is:

Washed or semi-washed Arabica single-origin, high altitude, to best release a wide aromatic range.

Paul, Ernani’s roaster, prefers the Indian Kalledevarapura.

While I love the Ethiopian sidamo.

Do you want to practice this method and also discover all the other Brewing techniques and equipment?

We look forward to seeing you at Ernani Academy’s Brewing class!

Email [email protected] to get all the information!

Marketing, E-commerce e Social Media Manager
Coffee Lover


Martina Mazzoleni

Marketing, E-commerce e Social Media Manager Coffee Lover

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