Mild-Mannered Canadian Fury

Doug Stephen is Politely Peeved

A Chemex Iced Coffee Technique


Wed, 05 Jun 2013 Ā«permalinkĀ»

It’s no secret that I love coffee. And for those of you that don’t live down here in Florida and have never been here this time of year, let me share a little secret with you: It’s hot as shit this time of year, and only gets hotter through August.

So it shouldn’t be surprising that a non-trivial portion of my adult life has been spent on trying to find the perfect iced coffee. It’s a finnicky drink to get right, with all sorts of caveats and workarounds.

Coffee itself is a complex extraction of oils, and oils do weird things when exposed to light, air, and heat. Hot brewed coffee can have it’s flavor changed really quickly by just sitting around, which is my most iced coffee methods involving hot coffee tend to revolve around making a sort of high-octane “concentrate” that goes directly over ice, getting diluted. On the other end of the spectrum we have cold-brewed coffee, which is a hit-or-miss topic with a lot of people; many of the flavors in coffee require heat to be extracted, so cold-brew just tastes different. Some people like it, some people don’t. I, personally, don’t mind cold-brewed coffee, but there is something to be said about the flavor of hot brew.

Up until recently, I had been using Marco Arment’s AeroPress Iced Coffee Recipe with great results. But in my never-ending quest for perfection, I decided to do a quick Google Something1 search for other ways to make iced coffee using the other gear in my armory. Specifically, I was interested in seeing what people had come up with for making iced coffee in a Chemex. To that end, I can’t take all of the credit for this idea, but I have made some tweaks to it. My roommate and I have been drinking this for a week or two now and it’s fantastic.

The idea is based on the third technique in this iced coffee article on OQ Coffee; the cold bath method. The idea is to submerge the Chemex carafe in an ice bath so that the coffee becomes instantly cooled as it drips down. This allows you to get all of the flavor of our hot brew without it staling/breaking down from sitting at higher temps for an extended period to cool down or diluting it with ice. My primary tweak to the recipe is that I don’t make a standard Chemex brew; I use a finer grind and a more dense coffee ratio so that I still get a sort of “concentrate” and a slower drip/better cooling effect. Even though the ice won’t melt as quickly, it’ll still melt pretty fast here in Florida. Plus, iced coffee is one of the only times that I do enjoy adding cream and sugar2 to my coffee.

With that out of the way, here’s my Chemex iced coffee “recipe”:

  1. Weigh out your water and coffee. My standard ratio for my Chemex is around 0.0625 grams of coffee per gram of water. For iced coffee, I like 0.09375 grams of coffee per gram of water. For example, my standard carafe of chemex is around 40 grams of coffee with 640 grams of water; an equivalent for iced coffee is 60 grams of coffee for 640 grams of water. Probably a good idea to pre-measure your water, since the weight of the ice bath might be a bit much to set the tare on a kitchen scale (I know that my cheapo scale can’t take that much weight).

  2. Bring your water to boil, and grind your cofee. I tend to go a little finer than normal; on my uncalibrated Baratza Encore, where I typically use an 18 for Chemex, I go down to around 12 or 13 for iced Chemex.

  3. Place the empty Chemex carafe with rinsed filter in a large empty bowl, and fill with a healthy amount of ice and a little bit of water. Heed the warning from the original site; a chemex full of air will get bobbed around if you use too much water, and could tip over or damage itself. It helps if you add the coffee to the filter before making the ice bath to add a little extra weight.

  4. Brew your chemex similar to how you normally would, blooming the coffee with a small amount of water for 30-40 seconds before finishing the pourover, avoiding the edges. Because the ground coffee is so much finer, I like to start off the first pour after the bloom by adding a little more water than I normally would and then using a bar spoon or similar tiny stir stick to agitate the water and grounds by stirring. After that, just keep the water level pretty constant until you’ve finished the pour.

  5. Enjoy. I like to portion out the coffee in to several mason jars, a 60/640 is good for about 3 or 4 drinks. I put the mason jars in the fridge, and then grab one, add some half-and-half + simple syrup, ice, lid, shake, and out the door in the morning.


  1. Hello darkness, my old friend.

  2. Or more properly, simple syrup if it’s iced coffee.