Target Roast Level
Select a target roast level to see temperature and time guidance.
Roast Phases
Understanding the three key phases of a coffee roast.
Moisture is driven from the bean. The aroma shifts from green/grassy to hay-like and then to bread-like. Keep ROR steady and avoid scorching by ensuring adequate airflow and moderate heat application.
The browning reaction develops sweetness and complexity. Sugars and amino acids react to create caramel, chocolate, and nutty precursors. This is where the core flavor structure is built.
Also called post-crack development. The bean expands, oils migrate, and acidity degrades while body and caramelized notes increase. The length of this phase defines the roast color and finish character.
Common Defects
What to watch for and how to avoid the most common roast defects.
Baked
- Cause
- Too low heat for too long, especially after first crack.
- Sensory Impact
- Flat, dull, papery, lacking sweetness and acidity.
- Prevention
- Keep ROR above zero. Avoid long, low-temperature stretches.
Scorched / Tipped
- Cause
- Too much heat early or on soft beans. Bean tips burn.
- Sensory Impact
- Burnt, smoky, sharp carbon notes.
- Prevention
- Reduce initial heat. Increase airflow. Watch bean surface color.
Underdeveloped
- Cause
- Dropped too early, before full first crack or with insufficient development.
- Sensory Impact
- Grassy, astringent, sour, lacking sweetness.
- Prevention
- Ensure adequate DTR. Wait for full first crack before drop.
Overdeveloped / Roasty
- Cause
- Too long in development, too high drop temperature.
- Sensory Impact
- Burnt sugar, carbon, thin body, harsh finish.
- Prevention
- Use DTR targets. Monitor bean temperature closely.