How to Brew Coffee with a Chemex: A Hassle-Free Step-by-Step Guide

If your Chemex coffee takes forever to drain, comes out bitter, or tastes weak and flat, know that the problem isn’t your brewer. The Chemex is one of the most iconic methods in the world, created in 1941 by German chemist Peter Schlumbohm, but it demands a brewing technique completely different from traditional drippers. Trying to make Chemex coffee the same way you’d make a Hario V60 is a surefire recipe for clogging the filter and getting frustrated.

In this practical, straight-to-the-point guide, you’ll understand the physics behind this classic method and learn a simple step-by-step process to extract a crystal-clear, sweet, and highly aromatic cup. By adjusting the grind, the timing, and how you pour the water, you’ll turn the Chemex into your favorite method for enjoying Brazilian specialty coffees.

Why is the Chemex unique (and why does the filter change everything)?

The Chemex is carved from a single piece of borosilicate glass — the same heat-shock-resistant material used in chemistry labs — paired with an elegant wooden collar. But the real secret behind the standout flavor it delivers is its exclusive paper filter. It’s about 20% to 30% denser and heavier than the common paper filters found on the market.

That thicker paper acts as an almost perfect barrier against essential oils (the lipid compounds in the bean that bring body and cloudiness to the drink) and traps even the tiniest coffee particles. The final result in the cup is a translucent, bright, and light drink, letting the coffee’s most delicate sensory notes stand out with no bitterness or solid residue in the mouth.

However, the carafe has a crucial feature: since it’s completely smooth on the inside, its only air outlet is the front spout channel. If the filter folds over and sticks to the glass, blocking that channel, the airflow gets cut off. With no room for air to escape the carafe, percolation — the process in which water moves through the coffee bed by the force of gravity — simply stalls and the filtering stops.

Equipment and ratios for the ideal brew

To get consistent results instead of relying on luck, controlling your ratios is essential. Using a simple kitchen scale transforms your routine and guarantees every cup comes out right, every morning.

• Freshly roasted specialty coffee: Go for whole beans with a high cupping score. The terroir — the term describing the unique combination of soil, climate, and altitude of the farm — really shows through in the Chemex’s clarity.
• Brew ratio: We recommend a ratio of 1:15 to 1:16. Use 30g of coffee to 480ml of water to serve two generous cups.
• Medium-coarse grind: The grounds should have a particle size similar to coarse kitchen salt. That texture lets the water flow smoothly through the dense filter.
• Clean, heated water: Use filtered or mineral water heated between 92°C and 96°C (right after the first boiling bubbles appear).

To get the right particle size without generating excess fine dust, a manual grinder fitted with burrs (internal steel or ceramic pieces that grind the beans evenly, unlike blades, which just chop the coffee into uneven sizes) is the most important piece of kit you’ll own.

Hassle-free step-by-step for making Chemex coffee

Follow this simple routine to extract the most sweetness and aroma without stalling your filter halfway through.

1. Fold and position the filter strategically: Open the conical paper filter so one side has three layers and the other has one. Position the three-layer side facing the carafe’s spout. This reinforces the paper’s structure and keeps it from folding inward and blocking the air channel.
2. Scald the filter with plenty of hot water: Pour boiling water across the entire paper. This generous rinse removes the leftover papery taste and warms up the glass carafe. Discard all the rinse water through the side spout without removing the filter from its place.
3. Add the grounds and create a well in the center: Pour the 30g of ground coffee into the filter and give the side of the carafe a few light taps to level the bed. Using your finger or a stick, make a small well in the center of the grounds to help the water go in evenly.
4. Do the bloom: Pour about 70ml to 90ml of hot water in circular motions starting from the center. Wait 45 seconds. This moment is called the bloom, the stage where freshly roasted beans release the carbon dioxide gas trapped from roasting, so they can absorb the water properly.
5. Pour gently and in a steady rhythm: Complete the total amount of water in 2 or 3 circular pours from the center outward, without pouring water directly onto the filter’s walls. Keep the water flow calm and avoid agitating the grounds aggressively.
6. Wait for it to fully drain and serve: Let the water drain naturally. The total Chemex brew time should fall between 4 and 5 minutes. Discard the filter with the grounds, give the carafe a gentle swirl to mix the brew, and serve.

Practical secrets so your filter never clogs again

If your brew usually runs past 6 minutes and leaves the coffee tasting bitter and astringent (that mouth-puckering sensation), apply these two fundamental technical adjustments.

1. Reduce agitation and fines migration

During grinding, it’s unavoidable that tiny microscopic particles called fines (ultra-fine dust) form. If you pour the water too forcefully or agitate the coffee violently, fines migration occurs: these particles float and get pushed down to the bottom of the cone, sealing the thick paper’s micropores. Gentle pours with a gooseneck kettle prevent that excessive turbulence.

2. Keep the air channel ventilated

If the paper sticks to the glass of the spout channel during rinsing or pouring, slip a glass rod, a stainless-steel skewer, or even the handle of a spoon between the paper and the Chemex’s wall. This ensures constant airflow and keeps internal pressure from stalling the liquid’s descent.

Chemex vs. Hario V60: what’s the difference in the cup?

Although both use paper filters, the sensory experience of each method is quite distinct:

• Chemex: Longer brew time (4 to 5 minutes), thick paper, and an exceptionally clean drink, with light body, balanced acidity, and very noticeable sweetness.
• Hario V60: Faster flow (2.5 to 3.5 minutes) thanks to the internal spiral ridges and thinner paper, delivering a coffee with more body and lively acidity.

Turn your daily coffee into a sensory experience

Making Chemex coffee is a contemplative ritual that rewards attention to detail with one of the most elegant cups in the specialty coffee world. By respecting the natural filtering time and controlling the grind, you eliminate unwanted bitterness and discover surprising flavors in your favorite bean.

How about setting aside a freshly roasted specialty coffee, brewing your Chemex with these tips, and trying it without sugar today? You’ll be surprised by the natural sweetness that was hiding in your cup all along!

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