Brew Guide: Chemex

It’s a thing of beauty. So beautiful in fact, that over 70 years ago it was added to the collection by the Museum of Modern Art. It can also be found in the Smithsonian and the Philadelphia Museum of Art. A science experiment and a piece of art all at once, the Chemex is a type of pour over drip brewing system that was created by German born American Peter Schlumbohm in 1941. With all this beauty you have to ask yourself… is it functional? The Chemex is a well rounded creation. Beautiful, functional and affordable.

But is this beautiful beast THE BEST way to prepare coffee? That question really isn’t fair, since there are a million and one brewing methods out there.  It’s kind-of like asking if Ferrari is the best car for racing. Of course it is…. depending on the track.  But if you can somehow get to know a guy who has some micro-lots of Burundi coffee, this is quite possibly the best way to get the most out of Burundi’s raspberry, caramel and citrus finishing beans. Having a Chemex and a Burr hand grinder has allowed us to have great tasting coffee on the (very frequent) mornings when there is no electricity here in Burundi. Get a fire going for some hot water and you are away.

Here’s my Chemex brewing method:

Start by boiling a kettle of water. Grab your Chemex, your beans, and a filter (Chemex filters). The filter does matter. Although we are currently using unbleached filters, many believe that the slight taste advantage belongs to a Chemex brewed while using oxidized filters. The vote is this produces a less “papery” tasting coffee.

Place the filter in the Chemex with the doubled up portion of the filter in front of the spout.

Pour the boiled water over the paper to rinse the filter.  This not only rinses any flavor taints out of the filter,  but will also serve to pre-heat your Chemex. We believe around 8 oz. of just boiled water will do the trick, but many believe you should rinse the filter with as much as 16 oz. of water or even an excessive 32 oz!

Next is the most important step.  Grind freshly roasted coffee.  I use one 12g scoop for every cup of coffee I’m making. In this case I used 6 scoops of coffee for my 6 cup Chemex.  If you don’t have a fancy plastic scoop, it’s about one heaping tablespoon of beans per cup.  You can use pre-ground coffee, but you will loose so much of the magic that you might as well be making instant coffee.  The grind should be set between a filter setting and a French press courseness.

It should be just fine enough that when you just barely wet the grounds no liquid drips through.

Empty the hot water from your pre-heated Chemex, place your wet filter back on the Chemex, and pour in the ground coffee.
Now is time for what coffee geeks like to call “the bloom”.

Re-boil the kettle if necessary (after wetting the filter) and pour just enough off boiled water (30 seconds from boiling is approximately the right temperature, but play around with this depending on what coffee you are using) onto the grounds to wet them.

This wetting of the grounds helps in achieving a slow, even extraction… giving you the best possible flavors.  The chemistry of the hot water reacting with the freshly roasted and ground coffee is beautiful.  The coffee expands or “blooms,” bubbling on the surface. This bloom is bloomin’ gorgeous to see, and turns coffee making into an event to be shared.

Thirty-five seconds after it blooms it’s ready to be brewed.

Slowly pour the water onto the grounds in a circular motion.

Be careful not to pour too close to the edges as this will cause under extraction and can create tunneling.

This slow even pour should take you at least a minute.  Pace yourself because you do not want to top up or brew a second time after finding you didn’t have enough space for your six-eight cups of water in the slow brewing filter.  By pouring a second pot of water over the grounds you would end up over extracting, filling your cup with bitter flavors.