Inspired by laboratory equipment, the Chemex is not only an excellent coffee brewer but also an enduring example of simple design that has maintained its cult following over the years, even earning a place in the Museum of Modern Art in New York City.
The Chemex is a range of coffee brewing devices designed in 1941 by chemist Peter Schlumbohm Ph.D..
Born in Kiel, Germany in 1896, Schlumbohm received his doctorate in Chemistry from the University of Berlin before moving to the USA in 1936, settling in New York. Schlumbohm was a prolific inventor. By the time of his death he had registered over 3000 patents. One of his most enduring designs is the Chemex, which has remained unchanged through the years, and is produced today in Chicopee, Massachusetts.
Inspired by laboratory equipment, the Chemex is not only an excellent coffee brewer but also an enduring example of simple design that has maintained its cult following amongst enthusiasts and in popular culture over the years, even earning a place in the Museum of Modern Art in New York City.
Making coffee with a Chemex is very simple – install the filter and wet it, add measured coffee, and pour water through. When complete, the filter is lifted out and composted and the brewer can go in the dishwasher (remove the wood and leather first). The brewer is beautiful to look at as it drips, and there is a succinct delight in making excellent coffee with such a low-tech, old-fashioned device.
The Chemex uses a proprietary range of bonded paper filters, once again inspired by laboratory equipment. The cone shaped, multi-layer folded paper filters are significantly (20-30%) thicker than many other papers, trapping more oils and limiting flow rate – a unique brewing method that leads to exceptionally clean and crisp, light-bodied brewed coffee. Different sizes of Chemex will require different size filters.
Due to their design, the Chemex brewers work best when brewing their specific intended batch sizes. The Six Cup model makes 850g of coffee, while Three Cup makes 500g.
Chemexes work best when making their intended batch size or close to it. This is a quirk that comes from the combination of extremely thick filters and the narrow tapered brew bed. This means that for the 3 cup, you should make coffee using between 400 – 550 g water, and between 750 – 900g for the six cup. Brewing ratio, of course, you can adjust, although we tend to stay around 1:17.
The brew should take between 3 and 6 minutes. Brewing time is determined by grind size. The grind size for a Chemex should be ‘medium’, approximately the consistency of raw sugar. See ‘Optimising your brew’ for more information.
You will need:
- A Chemex
- The correct size filters for your Chemex (FP-2 for Three Cup, SF-100 for Six Cup)
- Acaia scales
- Bonavita temperature controlled kettle
- Coffee grinder
- A chopstick
Here’s what to do:
- Install the filter in the Chemex and rinse it with boiling water. If using the FP2 filters for the three cup Chemex, you will need to fold it according to the instructions on the box. Install the filter with the multiple folds in the spout of the brewer.
- Take the filter out (gently) and tip away the water.
- Weigh and grind the appropriate amount of coffee, then tip it into the filter, weighing again to make sure. Shake the brewer to level the coffee.
- Tare the scale and place the brewer on it.
- Pour twice to three times the coffee weight of 96˚water onto the coffee (e.g., if you are using 50g of coffee, use 100 – 150g of water) and start a timer. This is the ‘bloom’.
- Once 30 seconds has elapsed, give the slurry a gentle stir with the chopstick.
- Gently pour water in a rough spiral fashion from the inside to the outside until the water reaches halfway up the upper part of the brewer, making sure you sink any dark parts of the surface.
- As the coffee drains, continue to top up the water level to the same point, pouring water gently so you don’t agitate the bed of grinds.
- Once you reach the target weight, let the brewer drain, remove the filter and compost it, give the coffee a thorough stir, and drink.