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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.

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  • Coffee Basics Nerds
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Article 8 of 12 in Roasting Fundamentals/
Charge temp and turning point

Key Concepts

  • Charge Temperature:

  • The temperature of the roaster drum or batch at the moment coffee beans are added.

  • Critical for determining the initial rate of rise (RoR) and drying phase duration.

  • High charge temp: faster initial Maillard reactions but risk of uneven development.

  • Low charge temp: slower start, longer drying, can preserve delicate flavors but risk underdevelopment.

  • Turning Point:

  • The lowest bean temperature reached immediately after beans are added to the roaster.

  • Beans initially absorb heat, often causing a drop in measured temperature.

  • Monitoring the turning point helps anticipate roast progression and adjust heat input accordingly.

Practical Implications

  • Charge temp sets the stage for the entire roast curve.
  • Understanding the turning point allows roasters to prevent thermal shock and achieve consistent RoR.
  • Adjustments to gas and airflow immediately after charge can stabilize the turning point and promote uniform development.

Tips for Roasters

  • Record charge temp and turning point for each origin to refine profiles.
  • Observe RoR immediately post-charge to avoid sluggish or overly aggressive starts.
  • Use consistent weighing and drum preheating to maintain repeatable charge conditions.

Summary

Mastering charge temperature and turning point dynamics is essential for controlling early roast stages, influencing bean chemistry, and producing predictable flavor outcomes.

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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.

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