Where conduction happens:

• Bean-to-drum contact

• Bean-to-bean contact

• Hot metal “scorch” points

What conduction does to flavor:

• Increases body

• Promotes caramelization

• Can produce heavier, roast-forward notes

Risks of too much conduction:

• Scorching (burn marks on surface of bean)

• Tipping (burned edges of the bean)

• Uneven development

• Bitter, ashy flavors

When conduction is strongest:

• High charge temperatures

• Low drum speed (more bean-to-drum contact)

• Low airflow

• Thick drum roasters