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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.

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  • Coffee Basics Nerds
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Article 7 of 12 in Roasting Fundamentals/
Gas, airflow, drum speed controls

Key Concepts

  • Gas/Heat Control:

  • Primary driver of bean temperature.

  • Higher gas increases environmental temperature; too high can scorch beans, too low prolongs drying phase.

  • Fine adjustments allow shaping of Maillard and development phases.

  • Airflow Control:

  • Regulates heat transfer and smoke removal.

  • Increased airflow can cool beans slightly but improve uniformity.

  • Critical for controlling bean color and surface appearance.

  • Drum Speed Control:

  • Ensures uniform rotation and exposure to heat.

  • Slower drum speed can allow deeper heat penetration but risk tipping.

  • Faster speed promotes more even drying and reduces local hot spots.

Practical Implications

  • Balancing all three controls is essential for consistent roast profiles.
  • Adjustments during first crack and development phases affect flavor, acidity, and body.
  • Experienced roasters anticipate thermal reactions and tweak controls dynamically.

Tips for Roasters

  • Start with a baseline profile for each bean origin.
  • Observe RoR and color changes while adjusting gas and airflow.
  • Record drum speed, gas, and airflow settings for reproducibility.

Summary

Understanding and mastering gas, airflow, and drum speed controls allows roasters to manipulate the roast environment precisely, ensuring consistent quality and desired sensory attributes in the final cup.

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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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