Brewing at Home: The CHEMEX®

Brewing coffee in the home is more than a way to wake us up, it is a morning routine bordering on ceremonial. Since the overwhelming increase in super-automatic, pod style brewing devices, many people have given up on even the simplest methods of home brewing. Generations before us always had to brew coffee the “old fashion way” which really only meant putting a paper filter into a brew basket, filling it with grounds, adding water to the machine, and turning it on. I know, so many steps! Now, many people around the globe are returning to the old way of doing things. Why? The answer is simple; it’s fun, and it tastes better.

In 1941 Dr. Peter Schlumbohm invented the CHEMEX®, a coffee maker that was to challenge the percolator found in most American homes. Being such an attractive device, the Museum of Modern Art displayed it as one of the best-designed products in 1943. The true difference in the CHEMEX® comes from its double bonded paper filter, also designed by Dr. Schlumbohm. CHEMEX®’s noticeably unique shape looks like something you’d find in a science lab, and there is very little irony in the fact that it was influenced by labware due to the non-porous glass that would not affect the coffee’s flavor.

Now let’s go over using this storied coffee brewing device, and learn some do’s and don’ts when it comes to brewing coffee with a CHEMEX®.

Brewing Instructions

  1. Place CHEMEX® Brand paper filter into your CHEMEX® brewer, and rinse.
    • Make sure the three-ply side of the filter paper is up against the pour spout of the brewer.
    • Pour hot water evenly over the empty filter to rinse out any paper taste. This also warms the entire vessel prior to brewing.
    • Dump the rinse water out by simple pouring it out via the spout. No need to remove the filter to do this, just leave it seated up against the glass.
  1. Add coarsely ground coffee to the device, and level.
    • If using a scale, place empty CHEMEX® on scale, and tare.
    • Your grind level should be courser than a regular drip grind, but not as course as a French Press grind.
  1. First pour: The bloom stage.
    • Evenly pour water that is just off boil (195-205 degrees F) over the coffee, getting all the coffee wet, but not filling the filter, and start your timer.
    • At this point you may stir the coffee to evenly saturate the grinds, and wait 30-40 seconds so gases release from the coffee.
    • You may notice the coffee bloom or blossom at this time, a sign of freshly roasted coffee.
  1. Second pour: Even coverage.
    • After the 30 seconds are up, start in the middle of the coffee bed, and evenly saturate the coffee grounds.
    • This is when you may remember a barista making fancy swirls with their kettle, seemingly showing off, however their technique is with purpose.
    • Fill the filter until the water level is one inch below the rim of the brewer.
  1. Final pour: Finish steadily
    • When your water level has dropped an inch, give or take, start your second pour.
    • Again, begin in the middle and pour in circles towards the edges. Try and hit any darker looking spots over lighter, as these will be less saturated pockets of coffee.
    • Fill the brew chamber and finish your brew by pouring right down the middle, avoiding the edges of the brewer.

The above steps will consistently yield delicious coffee, time and time again. If the brew is tasting off, make sure that the total brew time is between 4-5 minutes, and if it is outside this, adjust your grind size. Below are more steps to help you get started brewing amazing coffee with a CHEMEX® coffee maker.

Tips for Success

Water being poured into CHEMEX®

  • Measure: We suggest a 16 to 1 ratio. i.e. – 1000 grams water to 60 grams coffee
    • Using a scale simplifies this immensely.
    • If you do not have a scale, common household kitchen tools work.
      • One quarter cup scoop = 30 grams coffee (level for ground, heaping for whole bean coffee)
      • Use a liquid measuring cup to pre-measure your water
      • For water, milliliters on your measuring cups convert directly to gram
  • Pour: A spouted kettle is the best tool to use, but not necessary
    • Electric kettles can be found at many local coffee shops (Boil Line included) and are a great addition to any kitchen.
    • When pouring with a spouted kettle, you can use the water stream to agitate the brew in the first couple of pours by swirling the kettle side to side and up and down, helping to evening saturate your grounds and break up any clumps. You will want to stop this action during your final pours, opting instead to use a slower pour in the center of the brew. This will help to not knock your coffee off the sides of the filter, which will cause it to all settle in the bottom of your cone, clog, and result in over-extracted coffee. If your brew takes longer than 5 minutes, and is bitter tasting, this could be the reason.
    • If you do not have a kettle, just give it your all. Dust off an old tea kettle, use a regular pot and boil the water on the stove, microwave water in a Pyrex measuring cup. Whatever it takes, you’ll only lose out by not attempting.
      • Note: When you bring water to a boil, allow it to sit for around 1 minute in order to drop down to the above mentioned temperature range, assuming you are around sea level (above 5,000 feet just bring to a boil and start brewing).
  • Water: Filtered vs. distilled, what’s the difference?
    • Filtered tap water is your best option in home brewing. If you have a reverse osmosis filtration, we suggest using about 75% RO water and 25% regular tap water, as you need some minerals in order to properly extract your coffee.
    • Distilled water is not to be used when brewing coffee. All minerals have been removed from this water, and your coffee will not extract properly, resulting in a horrible tasting brew.
  • Have fun: Crafting delicious coffee shouldn’t be something you dread every morning, it should be what makes you jump out of bed. Manual brewing isn’t for everyone, as people are interested in different things, and have different time constraints. Although we can use some basic science to support the idea that the coffee you’ll make is “better” (sucrose levels, TDS, etc), we are encouraging this and other brew methods for the fun of it, not because we are stuck up coffee snobs.

1 Comment

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Tyler Paulsonreply
December 27, 2017 at 02:12 PM

These are great instructions Jeremy! The CHEMEX® is my favorite brew method. Not being afraid to crank up my grinder up to a much coarser setting was the best tip I received to stop the coffee from being over-extracted.

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