Connoisseurs love to challenge the difference between air roasting and drum roasting. Traditionalists still maintain their drum roasting method, while many prefer the new air roasting technique, claiming it delivers the purest flavor, in the shortest time possible.

Drum Roasters

Like the name suggests, it is a large drum that rotates over a heating source. The coffee beans are tumbled around inconsistently thus causing the different beans of the same batch to reach their optimal roasting temperature at different times.  Another aspect of the drum roaster is they do not have a way for the chaff to escape.  If you're unfamiliar with the term chaff, think of it like the skin of the bean.  During the roasting process when the bean gets hot enough, it will shed that skin.  Since drum roasters do not allow this chaff to escape, this causes the chaff to stick to the drum surface causing an underlying smoky burnt taste to the beans.

Drum-roasted beans are roasted "to color". This means that beans are considered done when they reach a desired color specified by the roaster. This can lead to inconsistencies between batches because color is a subjective measure of coffee beans.

Air Roasters

Air roasters use hot air from a blower to suspend the beans in a hot air convection current.  This convection current is known as a “Fluid Bed”.  This hot air evenly covers each individual bean thus eliminates many undesirable effects of drum roasting (scorching, facing, inconsistencies, etc.). This air also pushes the chaff out the exhaust vent allowing for a cleaner origin taste of the coffee.

Air roasters rely on more sophisticated temperature control sensors than what is found on drum roasters. The sensors on air roaster accurately measure the real-time temperature of the coffee beans as they undergo flavor changes. This allows air roasters unsurpassed roasting control, taking the coffee to the pinnacle of flavor development, without compromising on the clean smooth taste.

A drum roaster can take up to 15 minutes to complete a batch while an air roaster can roast the same batch of coffee beans in as little as eight minutes. The longer the coffee beans are heated, the less of the origin flavor will remain.  This is why it can be complicated to identify the source of a dark roast with drum roasting since they have longer roasting times. The added time in the roasting process adds more flavor of the roasting process and very little of the origin flavor of the bean. This is why air-roasted beans have a purer flavor opposed to drum-roasted beans.

Here at Five Star Coffee we went with Air Roasting because we wanted to make sure we provided a cleaner consistent flavor.  Air roasting gives us the ability to control the roast throughout the entire process and hit our flavor profiles every time.  Order some today and you’ll see what we mean!