Coffee Basics Pro

Color changes and caramelization

This topic explores how coffee beans change color during roasting and the role of caramelization in flavor development.

Coffee Basics Nerds avatar
  • Coffee Basics Nerds
  • 1 min read
Article 9 of 12 in Roasting Fundamentals/
Color changes and caramelization

Key Concepts

  • Color Changes:

  • Beans transition from green → yellow → light brown → medium brown → dark brown.

  • Yellowing marks the end of the drying phase and the start of Maillard reactions.

  • Color is a visual cue for roast stage monitoring and predicting flavor notes.

  • Caramelization:

  • Sugars within the bean start to break down and form complex aromatic compounds.

  • Begins around 160–180°C, overlapping with Maillard reactions.

  • Produces sweetness, body, and flavor complexity; excessive caramelization can lead to bitterness.

Practical Implications

  • Monitoring color change allows roasters to anticipate first crack and development time.
  • Proper caramelization enhances coffee sweetness and reduces vegetal or raw flavors.
  • Visual and sensor-based cues (color probes, spectrophotometers) can increase consistency.

Tips for Roasters

  • Use a color chart to compare bean surface color at key stages.
  • Adjust drum speed, airflow, and heat to control caramelization rate.
  • Combine visual assessment with aroma and sound cues (first crack) for optimal roast profiling.

Summary

Understanding color progression and caramelization is crucial for managing roast development and achieving desired flavor characteristics in the cup.

You might also like:

Comment

Disqus comment here

Coffee Basics Nerds

Written by : Coffee Basics Nerds

Expert coffee historians and brewing enthusiasts dedicated to sharing the rich heritage and techniques behind your perfect cup of coffee.

Recommended for You

Gas, airflow, drum speed controls

Gas, airflow, drum speed controls

This topic covers how key roaster controls—gas (heat), airflow, and drum speed—affect roast development, bean temperature, and flavor outcomes.

Endothermic vs exothermic transitions

Endothermic vs exothermic transitions

This topic explains the thermal events during coffee roasting, highlighting the difference between endothermic and exothermic reactions, and how these affect roast control and flavor development.

Charge temp and turning point

Charge temp and turning point

This topic explains the significance of charge temperature and the turning point in coffee roasting, and how they affect bean development and final flavor.

Bean temperature vs environmental temperature

Bean temperature vs environmental temperature

This topic explains the relationship between the bean temperature and the surrounding environment during roasting, how heat transfer affects roast development, and why monitoring both is essential.