Coffee Works' Sivetz "fluidized bed" Roaster

Roaster Stevan Teague weighs out a batch of green beans

In 1982 Coffee Works was among the first to adopt the "fluidized bed" roasting techology which was patented by coffee roasting visionary Michael Sivitz in 1981. Today we are on our second Sivitz roaster, having replaced our one-third bag with a half bag model in 2002. Using a Sivitz enables us to roast coffee with optimal development of and minimal intrusion over the natural flavors, which has helped us to focus our cup attention on the coffee rather than the roast.

The elegance of the Sivitz design comes from the same principle underlying convection ovens: The rate of heat transfer to the bean is a factor of the speed of the heated air passing the bean surface. Higher speed heat transfer improves coffee roasting because it affords both lower roasting temperatures and shorter roasting times, both major factors in avoiding charring, the most common cause of bitterness in coffee. Shorter roasting times also result in minimized destruction of the natural volatile organic compounds (VOCs) -- preserving the essential whoosh to fresh coffee flavor.

Moreover, the powerful airstream which suspends the beans (the "fluidized bed") carries away the lighter particles of dirt, dust, and chaff which are present in a natural product like coffee. This cleansing airstream gives Sivitz-roasted coffees their characteristically cleaner taste, free of grime and foreign matter.

Roasting is one of the three fundamentals of the coffee roaster's craft; the others being sourcing (selecting and buying) the best beans, and the epicurean art of blending coffees to create full, rich, and satisfying infusions. Using a more efficient coffee roasting technology is not only a wiser use of the planet's resources, but leads to higher definition of the subtle flavors inherent to natural coffees, uncovering a richer palate for flavor compositions.

Coffee beans in the cooling bin after roasting.