Those who have tasted coffee using this roasting method would attest that hot air roasted coffee beans are superior in flavor to drum roasted beans.
Not unlike a hot air popcorn maker, a hot air coffee roaster circulates the beans around the roaster with hot air, which propels them through the roasting process. A natural gas burner provides heat for the roasting process and the hot air moves the coffee, rather than the roaster manually moving the beans (in the case of drum roasting).
In the conventional drum roasting method used by most roasters, a hot steel drum is what moves the coffee beans, which tends to scorch the beans. The beans are added to the roaster at extremely high temperatures and water begins to immediately evaporate from the them before the sugars are allowed to caramelize.
Plumes of smoke when drum roasted coffee is released from the roasting chamber into the cooling bed. (You won't see this with the hot air roasting method.)
In contrast, a hot air roaster keeps the coffee beans moving and they never rest against the hot steel of a roasting chamber. The forced air circulates the beans which produces a much more even roast. During this process, hot air is vented out of the roaster which also forces out any foreign particles and chaff. Chaff is a thin, delicate layer that covers the beans and is the final layer of the coffee cherry pulp in the roasting process. During the roasting process each batch of coffee begins at low temperatures, and is built up to a specific temperature (depending on the roast) and the beans are allowed to cool before being emptied from the roaster. The end result is a cleaner coffee that tastes smoother, is more consistent and far less carcinogenic than coffee produced by drum roasters.
By now you must be wondering why more roasters don’t use the hot air roasting method. The answer is one of economies of scale - a high capacity drum roaster produces more coffee in a given time period that than a hot air roaster does. This makes drum roasting more economical and roasters can produce more batches per hour. At Bean Hoppers we are more committed to the quality of our coffee than the quantity and we are happy to bring this great tasting coffee to you at the same price as drum roasted coffee.
A Hot Air Roaster