How to Make the Perfect Cup of Coffee with a Chemex
Quick answer: To make Chemex coffee, use a 1:16 ratio: 20 grams of medium-coarse coffee to 320 grams of water at about 200°F for one large mug, or 40 grams to 640 grams for two to three cups. Rinse the filter, bloom with twice as much water as coffee for 30 to 45 seconds, then pour the rest slowly in circles. The whole brew takes about 3½ to 5 minutes, depending on the size.
We brew pour overs every day in our two Lakeville coffee shops. Here's our Chemex recipe and how to fix a cup that doesn't taste right.
Our picks for Chemex: Abstract Blend brings honey, berry and cacao notes, and the Chemex's clean, bright style shows off its fruitier side. Every bag is roasted fresh in small batches, with the roast date on the bottom.
In season now: Perennial Blend, our light roast with orange marmalade, candied almond and jasmine notes, is made for a Chemex.
Single origin: our Ethiopia is floral and fruit-forward, the classic Chemex coffee. Grab it while it lasts.
What Is a Chemex?
The Chemex is a glass pour over coffee maker invented in 1941 by German-born chemist Peter Schlumbohm. Its hourglass shape is both the brewer and the carafe, and the wood collar with its leather tie lets you hold it while it's hot.
What makes a Chemex different from other pour overs is its filter. Chemex filters are much thicker than standard paper filters, so they hold back more of the coffee's oils and fine particles. The result is an exceptionally clean, bright cup with a lighter, almost tea-like body.
Chemex Coffee Ratio
| Size | Coffee | Water | Bloom | Total time |
|---|---|---|---|---|
| 1 large mug | 20 g | 320 g | 40 g | About 3½ to 4 min |
| 2 mugs | 30 g | 480 g | 60 g | About 4 min |
| 2 to 3 mugs | 40 g | 640 g | 80 g | About 4½ to 5 min |
All based on a 1:16 ratio. For a stronger cup, try 1:15. For a lighter one, try 1:17.
What You Need
- A Chemex and Chemex filters
- Fresh whole bean coffee
- A burr grinder
- A kettle, ideally with a gooseneck spout
- A kitchen scale and a timer
How to Make Chemex Coffee, Step by Step
1. Heat your water. Bring filtered water to about 200°F, just off the boil.
2. Set up and rinse the filter. Open the filter so one side has three layers, and place that thick side against the spout. This keeps the filter from collapsing into the spout and blocking airflow. Rinse the filter with hot water to remove any paper taste and warm the glass, then pour out the rinse water.
3. Grind your coffee. Weigh 20 grams and grind it medium-coarse, a little coarser than you would for a V60, about like coarse sand. The thick filter drains slowly, so a grind that's too fine can stall the brew.
4. Bloom. Add the coffee, gently shake it level, start your timer, and pour about 40 grams of water, twice the weight of the coffee, so all the grounds are wet. Let it bloom for 30 to 45 seconds while the trapped gas bubbles out.
5. Pour in stages. Pour slowly in small circles, keeping the water level about halfway up the filter, until you reach 320 grams. Avoid pouring directly on the filter paper.
6. Let it drain. Let the water finish dripping through. For 20 grams of coffee, the whole brew should take about 3½ to 4 minutes.
7. Remove the filter and serve. Lift out the filter, give the Chemex a gentle swirl and pour.
How to Fix Chemex Coffee
- Sour, thin or weak: grind a little finer or use slightly hotter water.
- Bitter or drying: grind a little coarser.
- Brew takes over 6 minutes or stalls: the grind is too fine, or the filter is blocking the spout. Check that the three-layer side faces the spout.
- Finishes in under 3 minutes: grind finer or pour more slowly.
Change one thing at a time so you know what made the difference. Our complete pour over guide explains the science behind each adjustment.
Chemex vs. Other Pour Over Brewers
Compared to a Hario V60, a Chemex makes a cleaner, lighter-bodied cup, brews larger batches and is a bit more forgiving. A V60 gives you more body and more control. See how the Chemex compares to the V60, Kalita Wave and Origami in our guide to pour over methods, or read pour over vs. French press.
Quick Answers
What grind size is best for Chemex?
Medium-coarse, about like coarse sand. It's coarser than a V60 grind because the thick Chemex filter drains more slowly.
Can I use regular filters in a Chemex?
You can, but the coffee won't taste like Chemex coffee. The thick Chemex filters are what give it its clean, bright cup, and standard filters can also clog the spout.
How many cups does a Chemex make?
The classic 6-cup Chemex brews up to about 30 oz, though most people brew 1 to 3 mugs at a time. The ratio table above covers each size.
How hot should the water be for Chemex?
About 195°F to 205°F. Start at 200°F and go a little hotter for light roasts.
