Iced Coffee with the Chemex

Great Japanese iced coffee using nothing but a Chemex.

There’s a saying that the hotter the coffee, the better. But these days, cold coffee is everywhere— from frappuccinos to iced coffee, cold brew, and so on. These types of coffee are just like regular coffee, except it has to be iced quickly in order to preserve the flavor. It can be easily done in your Chemex; we’ll show you how.

But first, a little bit of context. Iced coffee as we know it originated in Japan, around the same time that the Hario V60 was born. It spread quickly, although many people confused (and still do, to this day) iced coffee with cold brew.

The difference is quite simple: iced coffee is brewed with hot water and then it is iced (or chilled), while cold brew coffee is brewed using cold water.

Cold brew, coincidentally enough, was also first discovered in Japan. Brought over from Europe as a delicacy, Japanese aristocracy had little to no idea what to do with coffee back in the 17th century. It was only by accident that they discovered that coarse grounds stored in a jar with water at room temperature resulted in brewed coffee.

And this was the best way to enjoy a chilled coffee until iced coffee came along. The Japanese iced coffee (or Flash Brew) consists of brewing coffee with hot water, like you normally would, except you pour it directly over ice. This turns your coffee cold immediately, achieving a tastier, faster result.

How to make iced coffee with a Chemex

The trick of making good iced coffee -instead of watery iced coffee- is to settle down on a ratio (in this case, 1:16) and then divide the water between brewing water and ice. You’ll be using less water than usual for brewing, though it will all compensate with the ice. Here’s a short, but useful recipe for making iced coffee in a Chemex:


  • 30 grams finely ground coffee
  • 350 grams hot water for brewing
  • 150 grams of ice


  1. Place the ice cubes inside the Chemex, then place a filter and pour coffee grounds.
  2. Using hot water, pour about 60 ml to wet the grounds and allow a small bloom.
  3. Pour the rest of the water very slowly. Try to pour in a spiraling motion.
  4. At about 3 minutes in, you should be done.
  5. Serve immediately.

As a tip for those who like stronger coffee, you can brew a batch beforehand, pour into an ice tray, and wait for them to freeze. Using ice cubes made from coffee, your coffee will never feel diluted!

In this case, you can tweak the water quantity depending on the size of your Chemex. As the ice cubes are not going to water down the coffee, you can go ahead and use as much water as you like.

Now, in the course of finding out about cold brew and iced coffee you might have begun to ask yourself: “Which one is better?” There are advocates for each type, but we think that iced coffee, as presented before, is superior to cold brew.

The reason is that cold water cannot extract all of the compounds in coffee as well as hot water can. When in contact with hot water, a series of tiny chemical reactions are set in motion; these are what give coffee most of its fragrant aroma, as well as most of its delicious flavor. The heat is not used only to speed up the brewing process, but to make a better tasting beverage.

Lower acidity is one of cold brew’s most popular features. Cold brew coffee has significantly less acid than a hot or iced coffee but in terms of flavor it cannot compare to coffee that has been extracted using hot water between 195°F and 205°F (90-96°C).

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