Chemex Recipe

  • 30 grams of coffee
  • grind - medium course 
  • 500ml/ 17oz. H2O just off boil
1. Pour 45g/ 1.5oz bloom for 60 seconds, no agitation
2. Pour remaining water in concentric circles staying away from the edge, and matching the flow in to the flow out. The only agitation comes from the pouring pattern. Aim to finish pouring around 3-3:15 minutes
Finish time 4:00 - 4:15 minutes

Controlling for Variables

Ratio: the amount of water
The ratio for nearly all brewing methods begins with the ratio: 30grams: .5 liter/ 17oz

Dose: the weight or volume of coffee. Also called “throw”

Temperature: full boil, just off, slightly cooled. Thermometers can be your friend
Typically the water ought to be a bit “off the boil” or roughly a tough under 205 degrees.

Grind: fine for faster flowing brewer coarse for slower
This should be a simple thing to understand. If the water is meant to move through the coffee (clever, Chemex, cone filter, cloth filter) you would use a finer grind to allow the coffee enough surface area to extract more quickly. This is as opposed to having the water sit on the coffee(French press, cold brew) then you should have a coarser grind to allow less surface area, and prevent the coffee from over-extracting and becoming extremely bitter.

Time: the total time that water is in contact with the ground coffee
The starting point here would be that most brewing methods should finish in under 5 minutes, and not take less than 3 minutes. There are of course exceptions to this such as the 25-30 seconds for espresso, or 1 minute for Aeropress, and the 10-12 hours for cold brew.

Bloom: if utilized, how much water, how much agitation, how long
The bloom is the first interaction the ground coffee has with water. As the hot water hits the coffee it immediately gives off a large quantity of CO2. During the blooming stage the coffee is busy expelling gas and as such is relatively hydrophobic. That is that it basically repels water. We must wait through this stage in order for the water to penetrate into the coffee and begin its extraction process. How long and whether or not to employ any agitation is specific to how long ago the coffee was roasted, and what brewing style you are employing. Typically the fresher the coffee the longer it should bloom. The shorter the overall brew time the more likely you would be to agitate.

Turbulence: how much agitation, when, and how.
Turbulence is a big word for any type of agitation such as stirring or swirling or even the method in which you pour the water. Any type of turbulence increases the rate of extraction. Some brewing styles benefit from heavy turbulence and others, none at all.