Bitterness is a flavor often linked with coffee, but that doesn’t mean it should dominate. A well-roasted and properly brewed coffee can offer balance, where bitterness plays just a supporting role.

⚗️ What causes bitterness?

Coffee bitterness mainly comes from two sources:

  1. Chemical compounds created during roasting, especially degraded chlorogenic acids, which break down into bitter lactones and phenols.

  2. Over-extraction – when brewing extracts too much from the grounds, including bitter components.

🔥 Roasting influence

  • Light and medium roasts are generally less bitter and more acidic.

  • Dark roasts develop more bitter compounds (like phenols and carbonized solids), making espresso from these beans often taste much more bitter.

💧 Brewing & extraction

Longer brew times, overly hot water, or very fine grinds can lead to over-extraction. The result? Flat, bitter coffee lacking balance. The key is to optimize brew time, temperature, and ratio.

🌱 Bean variety

Robusta beans naturally contain more bitter compounds. Arabica beans tend to be milder and better balanced in bitterness, especially when sourced and processed with care.

📚 Conclusion

Bitterness isn’t a flaw – it’s a flavor component. In specialty coffee, bitterness should be gentle, rounded, and well-integrated, not overpowering. With the right approach, you can unlock a rich, balanced cup full of flavor.