Chemex Coffee: Recipe, Ratio, Filters and Grind Size

Key Takeaways

• 1Start with 30 g coffee and 480 g (16.9 oz) water at 94°C (201°F) in a 6-cup Classic. Use a medium-coarse grind; observe a 4–5 minute brew from first water.
• 2The spout is also an air channel. Keep the filter’s three-layer side there and check for a blocked channel before blaming the grind for slow flow.
• 3Chemex measures a cup as 148 ml (5 US fl oz). A 6-cup model has a nominal 887 ml (30 US fl oz) capacity, not space for six large mugs.

Highlights

Coffee and water

30 g + 480 g (16.9 oz)

Input ratio

1:16 by weight

Water temperature

94°C (201°F)

Brew time

4–5 minutes including bloom

What Is a Chemex?

A Chemex is an hourglass-shaped glass pour-over brewer. A folded paper filter sits in the upper cone; coffee drains into the lower vessel, which you can use to serve it. It is one member of the wider pour-over family.

Peter Schlumbohm designed the Chemex in 1941. MoMA’s collection record identifies its materials as borosilicate glass, wood and leather. The familiar collar is a grip; the spout has a brewing job as well as a pouring job.

Chemex Recipe

This is our measured starting recipe for a 6-cup Classic Chemex, yielding two small servings. It retains the earlier guide’s 1:16 ratio and makes the pours explicit. The manufacturer’s method uses a scoop-based dose and a roughly 30-second bloom; our 30 g dose, 94°C (201°F) water and 45-second bloom are editorial choices. Allow about seven minutes with hot water ready.

Recipe

Chemex: 30 g Coffee, 480 g (16.9 oz) Water

Makes:

2 small servings; measure the coffee collected

Time:

About 7 minutes with hot water ready; 4–5 minutes brewing

Print recipe

Ingredients

• 30 g coffee, ground medium-coarse
• 480 g (16.9 oz) brewing water at 94°C (201°F), plus extra water for rinsing

Equipment

• 6-cup Classic Chemex, compatible bonded filter, grinder, scale, timer, kettle and two small cups

Method

1. Open a matching bonded filter with three layers toward the spout. Place it in a 6-cup Classic Chemex, keeping the spout air channel open. Rinse with hot water and discard the rinse water.
2. Add 30 g medium-coarse coffee, level the bed and place the brewer on a scale. Zero the scale and keep it running without resetting between pours.
3. Start the timer and add 60 g (2.1 oz) water at 94°C (201°F), wetting all the grounds. Wait until 0:45 from the first water.
4. Pour gently over the coffee until the scale reads 240 g (8.5 oz) total, adding 180 g (6.3 oz). Let the water level fall before continuing; keep it comfortably below the rim.
5. Continue to 480 g (16.9 oz) total, adding the remaining 240 g (8.5 oz). Allow the coffee to drain, observing about 4–5 minutes from the first water. Check flow and taste rather than forcing an exact time.
6. Remove the filter, swirl the collected coffee and divide between two small cups. Measure the collected yield if needed; 480 g (16.9 oz) is brewing-water input, not finished drink weight.

Recipe notes

Editorial 1:16 starting recipe; not the manufacturer’s exact scoop-based formula.

Scale totals: 60 → 240 → 480 g (16.9 oz). Water additions: 60 + 180 + 240 g (8.5 oz). Rinse water is separate.

Keep the spout air channel open. Collected coffee weighs less than the input water.

Use a burr grinder. A gooseneck helps control the stream. Check filter fit before adding coffee; the 3-cup brewer uses a different filter format.

How to Brew Chemex Coffee

The bloom guide explains wetting the bed, while the ratio guide handles other batch sizes. Do not combine this sequence with the amounts from a larger recipe: 60 + 240 + 480 g (16.9 oz) would add 780 g (27.5 oz), not 480 g (16.9 oz).

Chemex Filters

Open the paper into a cone with three layers on one side and one on the other. The three-layer side faces the spout. Its extra support helps stop the paper collapsing into the air channel. Follow the manufacturer’s filter-folding demonstration for your filter format.

Open full size

Pre-folded squares such as FS-100 suit the 6-cup Classic; the 3-cup models and Funnex use the smaller FP-2 or FP-2N half-moon format. Check the filter packaging against your exact model. A regular cone paper may fit differently and change drainage. A reusable metal substitute creates a different filtration setup.

Our recipe rinses the paper and warms the glass. Chemex describes rinsing as optional, so it should not be presented as a manufacturer requirement. Empty all rinse water before weighing the brewing water.

What Does “6-Cup” Chemex Mean?

Chemex counts a cup as 148 ml (5 US fl oz). The Classic sizes therefore describe the vessel’s nominal capacity, not your recipe’s yield or a promise of that many mugs.

The milliliter values are calculated from the manufacturer’s 5 fl oz convention, rounded to the nearest milliliter. Grounds retain water, and the filter needs room for pouring. A larger batch usually needs its own grind and pouring adjustments.

Chemex Troubleshooting

A slow brew is not automatically bitter, and a fast brew is not automatically sour.

A slow drain sends me to the paper and spout first. If wet paper has blocked the air channel, I reposition it. Grinding coarser won't fix air that has nowhere to escape.

Stop adding water if the cone is approaching overflow; fix the setup before the next brew. The grind-size guide and extraction guide explain the variables behind these experiments.

How It Tastes

Bonded paper is designed to retain grounds and filter the beverage. It commonly gives a low-sediment cup that feels lighter than a metal-filtered French press. The manufacturer describes its paper as thicker than many competing filters; that does not mean it removes all coffee acidity or guarantees a particular flavor.

Choose beans by the flavors you enjoy. Light, medium and dark roasts can all be brewed in a Chemex.

Chemex vs. V60 vs. Kalita

Compare the complete setup, filter availability and recipe; the V60 and Kalita guides each provide their own starting method.

Cleaning and Care

Remove the wood collar and tie before washing a Classic Chemex. The manufacturer permits dishwasher cleaning of the glass, securely positioned away from other dishes; warm soapy water and a suitable brush are another option. Rinse well and let it dry. Follow current model instructions for warming the brewer; Chemex says not to microwave its products.

Caffeine, Calories and Serving Size

A 200 g (7.1 oz) serving of generic brewed black coffee corresponds to about 80 mg caffeine, 2 kcal and 0 g sugar in USDA reference data. This is a serving comparison, not a measured Chemex result.

Serving assumptions and sources

USDA brewed coffee, NDB 14209, lists 40 mg caffeine, 1 kcal and 0 g sugar per 100 g. Doubling those values gives the 200 g example. Actual caffeine depends on coffee, dose, extraction and collected serving; milk and sugar add their own nutrients. Some brewing water remains in the grounds and filter.

Common Questions Before You Brew

Can I Brew One Cup in a Larger Chemex?

Yes. Use the ratio guide to size a smaller batch at this recipe’s 1:16 coffee-to-water ratio. A shallower bed can drain differently, so adjust grind and pouring after tasting.

Can I Make Iced Chemex Coffee?

Yes, with a recipe that allocates water between the hot pour and ice. See Japanese iced coffee for that approach. Adding 480 g (16.9 oz) of hot brewing water to an unmeasured pile of ice changes this recipe’s dilution.

Do I Need an Expensive Kettle?

No. A controllable, safe stream matters more than a particular brand. Use a scale to check how much water you add and keep the brew comfortably below the rim.

Is a 4-Minute Brew Always Better Than a 5-Minute Brew?

No. The time window helps you notice a changed recipe or flow problem. Coffee, grinder, filter and batch size affect it. Taste the mixed coffee after it cools slightly before choosing the next adjustment.

Editor's Take

Sources and Further Reading

6 references

External links open in a new tab

Brewer guidance

• ChemexSix Cup Classic specifications and methodModel capacity, compatible filter codes and manufacturer brew sequence; our weighed recipe is an editorial alternative(opens in a new tab)
• ChemexFrequently asked questionsFive-ounce cup convention, rinsing, filter fit, slow flow and care(opens in a new tab)

Filter guidance

• ChemexFilter-folding demonstrationsThree-layer placement and the spout air channel(opens in a new tab)
• ChemexPre-folded square filter specificationsFilter thickness claim and excluded small models(opens in a new tab)

Design history

• Museum of Modern ArtChemex Coffee Maker, 1941Designer, date and materials(opens in a new tab)

Serving context

• USDA Standard ReferenceBrewed coffee, NDB 14209Generic serving data; caffeine on page 548(opens in a new tab)