How to Brew Chemex Coffee: Step-by-Step Guide

If you’ve ever admired the elegant glass hourglass shape of a Chemex but weren’t sure how to use it—or why your pour-over always tastes off—you’re not alone. The Chemex method is iconic, but making a great cup requires precision, patience, and the right technique.

To brew a proper cup with a Chemex, you’ll need a medium-coarse grind, a 1:15 to 1:17 brew ratio, fresh water heated to 90–96°C, and around 4 minutes total brew time—including bloom and two pours. Here’s the full breakdown.

What Is a Chemex and Why Use It?

The Chemex coffee maker has remained nearly unchanged since its invention in 1941 by German chemist Peter Schlumbohm. Its signature wooden handle and leather tie give it both form and function, while its hourglass-shaped borosilicate glass body is designed to enhance clarity and control during pour-over brewing. Its unique thick paper filter removes more oils and sediment than standard filters, resulting in a cleaner, brighter cup that highlights clarity over body.

How to Use a Chemex: Step-by-Step Guide

1. Heat Your Water and Prepare Equipment

Start by heating filtered water to between 90–96°C. While the water heats, set up your Chemex, filters, coffee grinder, and scale. Preheating the Chemex with hot water also helps maintain brew temperature and avoids thermal shock.

2. Measure and Grind Your Coffee

Weigh out 30 grams of freshly roasted whole coffee beans. For Chemex, use a medium-coarse grind—roughly the texture of coarse sea salt or slightly finer than what you’d use for French press. This grind allows for even extraction without over-extraction or clogging the filter.

3. Fold and Place the Filter

Use the Chemex-specific paper filter, which has three layers on one side. Fold the filter so that the thicker triple-layer section covers the pouring spout. Place the folded filter into the top of the Chemex, ensuring the spout is properly covered.

4. Rinse the Filter

Pour enough hot water to fully saturate the filter—about 100–150 ml—and let it sit for a few seconds. This step removes any papery taste from the filter and preheats the glass vessel. Discard the rinse water.

5. Add Coffee Grounds

Add the 30-gram dose of freshly ground coffee into the rinsed filter. Give the grounds a gentle shake to level the bed, which helps promote even water flow during brewing.

6. Start the Bloom

Begin your timer and pour just enough hot water—about 50–60 ml—to saturate all the coffee grounds. Let it bloom for 30–45 seconds. Blooming releases trapped CO₂ and primes the coffee for even extraction.

7. First Pour (Development)

After the bloom, continue pouring in a slow, steady spiral motion. Add roughly 100 ml of water, bringing the total to around 150–160 ml. Keep the water level consistent and avoid pouring on the filter walls.

8. Second Pour (Main Extraction)

Wait until the coffee bed settles (about 15–30 seconds after the first pour), then slowly add the remaining water. For a standard 1:15 to 1:17 brew ratio, aim for a total of 450–500 ml water. Your final brew weight should be around 480 ml using 30 g coffee. Pour in stages, maintaining even saturation and a steady flow rate to hit around 4 minutes total brew time (including bloom).

9. Final Drip and Serve

Once all the water has passed through the coffee bed and the dripping slows significantly—usually within 4 minutes total—remove the filter. Swirl the Chemex gently to mix the brewed coffee, then pour into pre-warmed cups or a carafe.

Chemex Brewing Tips & Common Mistakes

To get the best results from your Chemex, avoid grinding too fine (which can clog the filter and over-extract), pouring too fast (which leads to uneven extraction), or using water that’s too cool (which under-extracts and results in flat flavors). A gooseneck kettle is highly recommended for precise control during pouring. Also, always preheat your equipment and use fresh, high-quality coffee beans.

Frequently Asked Questions

What is the ideal coffee-to-water ratio for Chemex?

The recommended brew ratio for Chemex is typically 1:15 to 1:17. For example, use 30 grams of coffee with 450–500 grams (ml) of water. Adjust to taste, but staying within this range ensures balanced extraction.

What grind size should I use for Chemex?

Use a medium-coarse grind, similar to coarse sea salt. This size prevents over-extraction and filter clogging while allowing for even water flow through the thick Chemex filter.

How long should a Chemex brew take?

Total brew time—including bloom and pouring—should be around 3:30 to 4:30 minutes. If it takes much longer, your grind may be too fine; if too short, it may be too coarse.

Do I need a gooseneck kettle for Chemex?

While not absolutely required, a gooseneck kettle gives you the precision needed to pour slowly and evenly, which is critical for proper saturation and extraction in the Chemex method.

Why does my Chemex coffee taste weak or bitter?

Weak coffee is often due to under-extraction (too coarse grind, fast pour, or insufficient bloom). Bitterness usually means over-extraction (too fine grind, slow pour, or overly long brew time). Adjust grind size and pouring technique accordingly.

Recommended FrontStreet Coffee Beans for Chemex

For Chemex brewing, try FrontStreet Coffee’s Brazil Yirgacheffe – a medium-roast blend with citrus, floral, and clean sweetness. Also excellent is the Colombia Sidra, a washed coffee with juicy tropical fruit and honey-like sweetness thanks to its double anaerobic fermentation. For something deeper, the Lintong Mandheling offers a smooth, nutty profile with low acidity. All three highlight the clarity and balance that Chemex brewing is known for. Freshly roasted within 5 days · Orders placed before 17:00 ship the same day · Next-day delivery across most of Guangdong Province.