Chemex Coffee Brewing Guide (Video Tutorial)

Quick answer

• Use fresh, quality whole bean coffee, ground medium-coarse, similar to sea salt.
• Employ a Chemex-specific paper filter, pre-rinsed with hot water to remove paper taste and preheat the brewer.
• Maintain a consistent water temperature between 195-205°F for optimal extraction.
• Follow a 1:15 to 1:17 coffee-to-water ratio for a balanced brew.
• Pour water slowly and evenly, focusing on saturation and bloom, then a continuous pour.
• Allow the coffee to fully drip through the filter; do not rush the process.
• Regularly clean your Chemex to prevent residue buildup and off-flavors.

Who this is for

• Coffee enthusiasts seeking to brew exceptionally clean and nuanced coffee at home.
• Individuals who appreciate a manual brewing method that offers control over the extraction process.
• Anyone looking to elevate their morning routine with a visually appealing and delicious cup of coffee.

What to check first

Here’s what to consider before you start making your Chemex coffee.

Brewer type and filter type

A Chemex brewer is distinctive, typically made of non-porous borosilicate glass with a polished wood collar and leather tie. It’s designed for use with specific, thick Chemex paper filters. These filters are about 20-30% thicker than standard drip coffee filters, which contributes to the Chemex’s characteristic clean cup profile by trapping more sediment and oils. Ensure you have genuine Chemex filters, as other filters may not fit or perform correctly.

Water quality and temperature

The quality of your water significantly impacts the taste of your coffee. Filtered water, free from strong odors or tastes, is ideal. Avoid distilled water, as it lacks minerals necessary for good extraction. Aim for a water temperature between 195°F and 205°F. Water that’s too hot can scorch the coffee, leading to bitterness, while water that’s too cool will under-extract, resulting in a sour or weak brew.

Grind size and coffee freshness

For Chemex, a medium-coarse grind is recommended. It should resemble coarse sea salt. If the grind is too fine, it can lead to over-extraction and a slow drip time, resulting in bitterness. Too coarse, and the coffee will under-extract, tasting weak and sour. Always use freshly roasted whole bean coffee and grind it just before brewing for the best flavor. Coffee begins to lose its aromatic compounds quickly after grinding.

Coffee-to-water ratio

A good starting point for Chemex is a coffee-to-water ratio between 1:15 and 1:17. This means for every 1 gram of coffee, you use 15 to 17 grams (or milliliters) of water. For example, if you’re using 40 grams of coffee, you’d use 600 to 680 grams of water. Adjust this ratio to your personal taste preferences. Too much coffee can lead to an overly strong or bitter cup, while too little will result in a weak brew.

Cleanliness/descale status

Regular cleaning of your Chemex is crucial. Coffee oils can build up on the glass, becoming rancid and imparting unpleasant flavors to subsequent brews. Rinse your Chemex with hot water after each use. For a deeper clean, use a mild, unscented dish soap and a soft brush. If you notice mineral buildup from hard water, descaling with a vinegar solution or a commercial descaling agent is recommended. Check the manufacturer’s instructions for specific descaling guidelines.

Step-by-step how to make Chemex coffee

Here’s a detailed guide on how to make Chemex coffee at home.

1. Prepare your water.

• What to do: Heat filtered water to 195-205°F.
• What “good” looks like: Water is at the ideal temperature, ready to extract flavors without scorching or under-extracting.
• Common mistake and how to avoid it: Using tap water directly or water that’s not at the right temperature. Avoid by using filtered water and a thermometer or a kettle with temperature control.

2. Fold and place the filter.

• What to do: Fold the Chemex filter into a cone shape, with the three-layered side facing the pour spout. Place it in the Chemex.
• What “good” looks like: The filter fits snugly, covering the spout area with its thickest side.
• Common mistake and how to avoid it: Incorrectly folding the filter, which can lead to tearing or improper filtration. Follow the filter’s crease lines for proper folding.

3. Rinse the filter.

• What to do: Pour hot water (from step 1) over the filter, thoroughly wetting it. Discard the rinse water.
• What “good” looks like: The filter is completely saturated, and the Chemex is preheated.
• Common mistake and how to avoid it: Skipping this step or not rinsing thoroughly, leaving a papery taste in your coffee. Always rinse until the water runs clear from the filter.

4. Add coffee grounds.

• What to do: Grind fresh coffee beans to a medium-coarse consistency. Add the desired amount of grounds to the wet filter.
• What “good” looks like: Grounds are evenly distributed in the filter, resembling coarse sea salt.
• Common mistake and how to avoid it: Using stale pre-ground coffee or an incorrect grind size, leading to poor extraction. Grind fresh beans just before brewing and adjust your grinder for the correct consistency.

5. Bloom the coffee.

• What to do: Gently pour about twice the weight of the coffee grounds in water over the grounds, ensuring full saturation. Let it sit for 30-45 seconds.
• What “good” looks like: The coffee grounds visibly expand and release CO2, creating a “bloom.”
• Common mistake and how to avoid it: Pouring too much water or not allowing enough time for the bloom, which hinders proper CO2 release and even extraction. Use a scale for precision and observe the bloom.

6. First pour.

• What to do: After the bloom, slowly and evenly pour water in a circular motion, starting from the center and moving outwards, avoiding the filter walls. Pour until the Chemex is about two-thirds full.
• What “good” looks like: A steady, controlled pour that maintains an even bed of coffee and consistent saturation.
• Common mistake and how to avoid it: Pouring too fast or unevenly, creating channels in the coffee bed and leading to uneven extraction. Practice a slow, deliberate pour.

7. Second pour (and subsequent pours).

• What to do: Once the water level has dropped about halfway, repeat the slow, circular pouring motion until you reach your desired total water volume.
• What “good” looks like: The water level is consistently maintained, and the drip rate remains steady.
• Common mistake and how to avoid it: Letting the water level drop too low between pours, which can dry out the coffee bed and lead to under-extraction. Maintain a consistent water level.

8. Allow to drip.

• What to do: Once the desired water volume is reached, allow all the remaining water to fully drip through the coffee bed.
• What “good” looks like: The water has completely drained, leaving a relatively flat bed of spent grounds.
• Common mistake and how to avoid it: Removing the filter too early, resulting in a weaker brew, or stirring the grounds, which can release fines and lead to over-extraction. Be patient and let it finish naturally.

9. Remove filter and serve.

• What to do: Carefully remove the filter and discard it. Swirl the brewed coffee in the Chemex to ensure even mixing. Pour and enjoy!
• What “good” looks like: A clean, clear cup of coffee ready to drink.
• Common mistake and how to avoid it: Forgetting to swirl, which can leave layers of different strengths in your coffee. A quick swirl ensures a consistent taste in every cup.

Common mistakes (and what happens if you ignore them)

Mistake	What it causes	Fix
Using stale coffee beans	Flat, lifeless, or bitter flavor; lack of aroma.	Buy freshly roasted whole beans; grind just before brewing.
Incorrect grind size (too fine)	Over-extraction, bitterness, slow drip time, clogged filter.	Adjust grinder to a coarser setting (like sea salt).
Incorrect grind size (too coarse)	Under-extraction, sour, weak, or watery coffee.	Adjust grinder to a finer setting.
Not rinsing the filter	Papery taste in the final brew.	Always rinse the filter thoroughly with hot water before adding grounds.
Water temperature too low	Under-extraction, sour taste, weak body.	Use a thermometer or temperature-controlled kettle; aim for 195-205°F.
Water temperature too high	Over-extraction, bitterness, scorched flavor.	Let water cool slightly after boiling to reach the target temperature.
Skipping the bloom	Uneven extraction, muted flavors, gassy taste.	Perform a proper bloom for 30-45 seconds, saturating all grounds.
Pouring too fast/unevenly	Channeling in the coffee bed, uneven extraction, weak spots.	Pour slowly and deliberately in concentric circles, avoiding filter walls.
Incorrect coffee-to-water ratio	Too strong/bitter (too much coffee) or too weak/watery (too little coffee).	Use a scale for precise measurements; start with 1:15 to 1:17 ratio.
Not cleaning the Chemex regularly	Rancid coffee oil buildup, off-flavors, cloudy appearance.	Rinse thoroughly after each use; deep clean with soap and brush periodically.
Letting the brew sit too long	Over-extraction from residual grounds (if not removed), cooling.	Remove filter immediately after drip; serve promptly.
Using hard or unfiltered water	Unpleasant mineral tastes, scale buildup in brewer.	Use filtered water; descale brewer regularly if needed.

Decision rules for how to make Chemex coffee

• If your coffee tastes sour or weak, then your grind is likely too coarse or your water temperature is too low, because these prevent proper extraction of desirable flavors.
• If your coffee tastes bitter or astringent, then your grind is likely too fine or your water temperature is too high, because these lead to over-extraction.
• If your brew time is too long, then your grind is too fine or you’re pouring too slowly, because fines can clog the filter and slow pouring extends contact time.
• If your brew time is too short, then your grind is too coarse or you’re pouring too fast, because water flows too quickly through large particles.
• If you detect a papery taste, then you didn’t rinse your filter adequately, because the paper residue was not washed away.
• If your coffee lacks aroma or tastes flat, then your coffee beans are likely stale or not ground fresh, because freshness is key to vibrant flavor.
• If your coffee has an unpleasant aftertaste, then your Chemex might not be clean, because residual oils can turn rancid.
• If you observe uneven extraction (some grounds look dry, others saturated), then your bloom or pour technique is inconsistent, because water isn’t saturating the coffee bed evenly.
• If you’re struggling with consistent pours, then consider a gooseneck kettle, because it offers much finer control over water flow.
• If your coffee is too strong, then reduce the coffee-to-water ratio (e.g., from 1:15 to 1:16 or 1:17), because less coffee per amount of water will yield a lighter brew.
• If your coffee is too weak, then increase the coffee-to-water ratio (e.g., from 1:17 to 1:16 or 1:15), because more coffee per amount of water will yield a stronger brew.
• If your coffee is murky or has sediment, then your grind is likely too fine or your filter might be improperly placed, allowing fines to pass through.

FAQ

How much coffee should I use for a Chemex?

A good starting point is a 1:15 to 1:17 coffee-to-water ratio. For a standard 6-cup Chemex, this often translates to about 35-45 grams of coffee for 525-765 grams of water, depending on your desired strength. Using a kitchen scale for precision is highly recommended.

What is the ideal grind size for Chemex?

The ideal grind size for Chemex is medium-coarse, similar to the texture of coarse sea salt. This allows for optimal water flow through the thick filter and proper extraction without bitterness or sourness. A burr grinder is best for achieving a consistent grind.

Why do I need to rinse the Chemex filter?

Rinsing the Chemex filter with hot water serves two main purposes: it removes any papery taste that could otherwise transfer to your coffee, and it preheats the Chemex brewer itself, helping to maintain a stable brewing temperature. Always discard the rinse water before adding coffee grounds.

What’s the “bloom” and why is it important when making Chemex coffee?

The bloom is the initial pour of hot water over the coffee grounds, saturating them and allowing carbon dioxide to escape. This process, which typically lasts 30-45 seconds, is crucial for even extraction. If you skip the bloom, the trapped CO2 can repel water and lead to an inconsistent, less flavorful brew.

How long should a Chemex brew take?

A typical Chemex brew time, including the bloom, usually ranges from 4 to 5 minutes. If your brew time is significantly shorter, your grind might be too coarse. If it’s much longer, your grind might be too fine, or your pour technique could be too slow.

Can I reuse Chemex filters?

No, Chemex filters are designed for single use. Their thick paper construction efficiently traps sediment and oils, but once used, they are saturated with spent coffee grounds and oils that can impact the flavor of subsequent brews.

My Chemex coffee tastes weak, what should I adjust?

If your coffee tastes weak, you might need to use more coffee (adjust your coffee-to-water ratio to be stronger, like 1:15), or your grind might be too coarse, leading to under-extraction. Ensure your water temperature is also within the 195-205°F range.

How do I clean my Chemex?

After each use, rinse your Chemex with hot water. For a deeper clean, use a mild, unscented dish soap and a soft brush. For mineral buildup, you can use a solution of white vinegar and water, letting it sit before rinsing thoroughly. Avoid harsh abrasives that could scratch the glass.

What this page does NOT cover (and where to go next)

• Specific coffee bean recommendations or origins
• Advanced pour-over techniques like pulse pouring variations
• Detailed chemistry of coffee extraction
• Comparisons with other brewing methods
• How to calibrate your coffee grinder
• Different types of water filtration systems for coffee
• The history of the Chemex brewer