Chemex Brew Guide

The Chemex is an iconic pour-over coffee maker known for its elegant design and ability to produce a clean, bright cup of coffee. It uses specially designed paper filters that are thicker than standard filters, which results in a slower filtration process and a brew that highlights the subtle flavors of your coffee while removing oils and fine particles. This method requires patience and a bit of technique, but the results are well worth the effort. Here's your step-by-step guide to brewing the perfect cup with a Chemex.

1. What You Need

Equipment:

  • Chemex Coffee Maker: Available in various sizes (3-cup, 6-cup, 8-cup, etc.). The size you choose depends on how much coffee you want to brew at once.
  • Chemex Filters: Specially designed, thick paper filters. Use the size appropriate for your Chemex.
  • Coffee Grinder: A burr grinder is ideal for consistency. You’ll need a medium-coarse grind, similar to sea salt or kosher salt.
  • Kettle: A gooseneck kettle is recommended for precise pouring control.
  • Scale (optional): To measure your coffee and water for accuracy.
  • Timer (optional): To control the brewing time.

2. Coffee-to-Water Ratio

The general coffee-to-water ratio for Chemex is 1:15 (1g of coffee to 15g of water), but you can adjust it to taste. A typical starting point for brewing would be:

  • For 500ml of water (about 2 cups), use 33g of coffee.
  • For 750ml of water (about 3 cups), use 50g of coffee.

Adjust the ratio depending on how strong or light you like your brew.

3. Water Temperature

The ideal water temperature for Chemex brewing is 200°F (93°C), which is just below boiling point. If you don’t have a thermometer, bring your water to a boil and let it sit for about 30 seconds to cool slightly.

4. Brewing Process

Step 1: Prepare Your Equipment

  • Place the Chemex on your scale and set it to zero.
  • Use a Chemex paper filter and fold it along the crease (this creates a cone shape).
    • Place the folded filter in the Chemex, ensuring the three-layered side is facing the spout, with the thicker side against the walls of the Chemex. This helps ensure an even extraction.
  • Rinse the Filter: Pour hot water through the filter to rinse it. This removes any paper taste and pre-warms the Chemex. Discard the rinse water.

Step 2: Measure and Grind Coffee

  • Measure out your coffee (e.g., 33g for 500ml of water).
  • Grind the coffee to a medium-coarse grind, similar to sea salt. The grind size is important for even extraction—too fine, and it can clog the filter; too coarse, and the coffee will brew too quickly and taste weak.

Step 3: Add Coffee Grounds

  • Add the ground coffee to the center of the Chemex filter. Gently shake the Chemex to level the coffee bed. This ensures even extraction during brewing.

Step 4: Bloom the Coffee

  • Start your timer and pour about 60ml of water over the coffee grounds (roughly twice the weight of the coffee). This is called the bloom.
  • Let the coffee bloom for 30-45 seconds. During this time, the coffee will release carbon dioxide, which is a natural byproduct of the roasting process. Blooming helps to enhance the flavors in the final brew.

Step 5: Begin Pouring the Water

  • After the bloom, slowly pour water in a circular motion, starting from the center and working your way outwards, ensuring all the coffee grounds are evenly saturated.
  • Pour in stages: Pour around 100-150ml of water at a time. Allow the water to "drain" before adding more water. This gives the coffee time to extract fully from the grounds.

Step 6: Maintain a Consistent Pour

  • Continue pouring in a steady, circular motion, keeping the water level below the top of the Chemex. This allows for a consistent extraction and prevents the coffee from overflowing.
  • As the coffee brews, the water level will decrease. Keep adding water until you’ve reached your desired total amount of water. If you’re brewing 500ml of water, aim to finish your pour in about 3–4 minutes.

Step 7: Allow the Coffee to Finish Draining

  • After you’ve poured all the water, let the coffee continue to drain through the filter. This should take about 4-5 minutes in total. If your brew is taking much longer or shorter, you may need to adjust the grind size or pour technique for better extraction.

Step 8: Serve and Enjoy

  • Once the coffee has fully drained through the filter, remove the filter and discard the coffee grounds.
  • Pour the freshly brewed coffee into your mug, stir gently to mix any remaining layers, and enjoy!

5. Tips for Perfect Chemex Coffee

  • Grind Size: A medium-coarse grind is key to a good extraction. Too fine, and your coffee might taste bitter or over-extracted. Too coarse, and it will be under-extracted and weak.
  • Consistent Pouring: Use a gooseneck kettle for more control over your pouring. Pour in slow, controlled, circular motions to ensure even extraction.
  • Coffee Freshness: Use freshly ground coffee for the best flavor. Grind the beans just before brewing.
  • Water Quality: The quality of your water can significantly affect the taste of your coffee. Use clean, filtered water for the best result.
  • Pre-warming the Chemex: Always pre-warm your Chemex and filter to avoid cooling the brew down too quickly.
  • Tuning the Ratio: Experiment with the coffee-to-water ratio. If your coffee tastes too strong, reduce the amount of coffee. If it's too weak, increase the amount of coffee.

6. Troubleshooting Common Issues

  • Coffee Tastes Bitter or Over-Extracted:

    • Cause: Too fine a grind, over-brewing, or brewing at too high a water temperature.
    • Solution: Use a coarser grind, aim for a brew time of 4-5 minutes, and ensure your water is at the proper temperature (200°F or 93°C).

  • Coffee Tastes Weak or Under-Extracted:

    • Cause: Too coarse a grind, not enough coffee, or under-brewing.
    • Solution: Increase the grind size slightly, use more coffee, or adjust your pour technique to give the coffee more time to extract.

  • Brew Takes Too Long or Too Short:

    • Cause: An incorrect grind size or pour technique.
    • Solution: If the brew is taking too long, try a coarser grind. If it’s too short, try a finer grind or pour more slowly.

7. Cleaning and Maintenance

  • After Brewing: Once you've finished brewing, discard the used filter and coffee grounds.
  • Cleaning the Chemex: Rinse the Chemex with warm water after each use. For a deeper clean, use mild dish soap and a soft brush to scrub the inside. Avoid using abrasive materials that could scratch the glass.
  • Filter Maintenance: If you're using paper filters, make sure they’re clean and dry before use. Reusable metal filters should be cleaned regularly to prevent coffee oil buildup.

8. Conclusion

Brewing with a Chemex is a simple yet rewarding process that yields a beautifully clean and flavorful cup of coffee. With the right grind size, pouring technique, and timing, you can extract the nuanced flavors of your coffee beans, creating a smooth, vibrant brew. Experiment with ratios, steep times, and pour techniques to find your perfect cup. Whether you're a coffee beginner or an experienced brewer, the Chemex offers an exceptional coffee experience. Enjoy the process and your delicious cup of coffee!