THE SCIENCE OF CONVECTION DRUM COFFEE ROASTING

Coffee roasting with coffee drum technology is the oldest type of coffee roasting technology dating back to the Middle Ages.  More recent technology using electricity and even more recent utilizing HID lamp bulbs - high intensity discharge in the form of halogen lamp bulbs for instant on heat technology, halogen-coffee-roasting.  The convection roaster can be measured for efficiency by placing a hand anemometer just above the exhaust flange with the heating elements turned on.  Using this method the exhaust flue gases can be measured in MPG and converted to Feet Per Second (FPS).  Taking the cubic inch of coffee roaster inside measurement and calculating number of changes in the inside environment - this number is the Convection Rate.

Each coffee roaster has a convection rate based on this calculation.  The convection rate changes when the exhaust blower is on and yields a different convection rate number.