Flash Brew Iced Coffee

8 Cup Chemex

Dose: 80g

Grind: coarse

Ice: 380g

Brew Water: 580g

Yield: 960g

Time: 5-5.5 minutes

Flash Brewing is a simple variation on the pour over technique used for the Chemex, V60, Bee House and Kalita. The only difference is that in Flash Brewing we create a concentrate–brewed hot using less water than normal. This concentrate is brewed directly onto ice, cooling and diluting the coffee to the desired strength and temperature. Basically, we are using a little less than two thirds our Brew Water to

extract the coffee, and adding the remaining volume in the form of ice to the bottom of our serving vessel. This method works great in a Chemex due to the shock resistant pyrex glass, but you can substitute any brewer, so long as the vessel you brew into can handle the temperature fluctuation between the ice and hot coffee (canning or mason jars work quite well for this).

  1. Fold your Chemex filter and place it in the brewer so that the cone has three layers on the pouring spout side.
  2. Pre-wet the filter with hot water to wash out any papery taste. Discard the rinse water.  
  3. Being careful not to collapse or wrinkle the now wet filter, remove it momentarily in order to add your 380g of ice into the bottom chamber of the Chemex. Carefully replace the filter.
  4. Dose freshly ground coffee into the center of the filter and shake the brewer gently to settle the grounds.
  5. Using a spoon, make a small volcano in the center of the bed of grounds.
  6. Start your timer and vigorously add 240g (triple your dry coffee dose) of water directly to the center of the volcano, being sure to wet all the grounds.  Allow the coffee to “bloom”, or off-gas, for 30-40 seconds (the older the coffee, the shorter the bloom time).
  7. After bloom, maintain this water level, gently adding a little bit of water every ten seconds or so. Pour slowly, starting in the center of the grounds and spiraling outwards being careful to hit all the coffee evenly.
  8. Stop pouring when you’ve hit your total brew water weight of 580g.  
  9. Allow the coffee to “drop” or drain out into the lower chamber before removing the filter. This should finish at around 5-5.5 minutes.
  10. Discard filter and grounds, swirl the Chemex, pour, and enjoy!