Halogen Heat and Light Roasts

Halogen heating was discussed as a radiant heat source whose effect may depend on bean color. One community member compared it to sunbathing: darker colors absorb more heat, so beans that are already browner may be more strongly affected by halogen energy as the roast progresses. Treat this as a practical roasting observation rather than a quantified heat-transfer measurement. source

Implications for Light Roasts

One community member argued that halogen should be turned off for light roasts, reasoning that as beans become browner they absorb more halogen heat and may be pushed darker than intended. source

Another community member questioned whether that means halogen cannot be used for light roasts at all, suggesting instead that the key issue may be control speed: halogen output may need to be reducible faster to use it effectively in lighter roast profiles. source

Practical Takeaway

For light roasts, community discussion suggests being cautious with halogen late in the roast, especially as bean color darkens. Possible approaches include turning halogen off, reducing it earlier, or ensuring the profile allows halogen power to drop quickly enough to avoid excess development. source

Reported Dry/Yellow Cutoff Practice

One user reported asking Matt from Roest/Rose about halogen use and said Matt does not use the halogen past dry/yellow, describing the cutoff as “up to 150C.” This supports treating halogen as an early-roast energy tool rather than something to carry deep into Maillard or development, especially when trying to avoid excessive surface/radiant effects later in the roast. source

Hypothesis: Faster Internal Heating

A user hypothesized that halogen may raise the bean interior temperature faster than a more conduction-dominant roast. In that view, halogen could make faster roasts possible while reducing the temperature delta between the bean surface and interior. This should be treated as a practical hypothesis from roasting experience, not a measured heat-transfer conclusion. source

E-Roasting Course Practice

A community member reported that Morten keeps halogen either off or low in his e-roasting course. Treat this as a reported course/practice observation rather than a universal recommendation, but it supports the broader practical theme that halogen can be minimized when a gentler radiant contribution is desired. source