Roasting
Drum Roaster
The most common roaster type in specialty coffee, featuring a rotating horizontal drum heated by gas burners beneath or behind it. Drum roasters use a combination of conduction, convection, and radiation to transfer heat to the beans.
En Profundidad
The rotating drum tumbles beans for even heat exposure, while adjustable airflow controls the balance between conductive heat from the drum walls and convective heat from hot air. Batch sizes range from 100 grams (sample roaster) to 250+ kilograms (production roasters). Iconic drum roaster manufacturers include Probat, Loring, Giesen, and Diedrich. Loring's Smart Roast series uses a single-burner convection-recirculation design that reduces emissions and fuel consumption by up to 80% compared to traditional drum machines.