Coffee Bean Roasting 101: Part 1 Processing and Roasting

Processing and Roasting

Coffee Cherry: Coffee beans are actually coffee seeds that make up the pit of a coffee cherry. Coffee cherries are picked when they are ripe, and bright red in color. The pulp and mucus is removed, most of the time mechanically, and the coffee seeds are then either set out to dry (natural dry process), or sent to a fermentation tank where the coffee seeds are set in water, and allowed to ferment for anywhere from ~.5day or 1.5days, removing the mucilage from the seed. The coffee seeds are often sorted out by density (higher density being higher quality) at this time, as higher density coffee seeds will sink.

Coffee Processing: See Coffee Cherry

Cooling tray: The cooling tray is usually circular, and equipped with stirring arms that agitate the just-out-of-the-roaster coffee with air being pulled through the tray (and through the mass of freshly roasted beans) to halt the roast by bringing the temperature of the beans down from over 400F down to room temperature. Without forced cooling, the beans would continue to roast beyond the intended rate.

Degas: The time needed for a batch of coffee to release Carbon Dioxide for optimum flavor. More degassing is necessary for optimum espresso than is needed for brewed coffee.

Green Coffee: The coffee seed before it is roasted, and after it is processed and dried. This is the form coffee is in when it is purchased by a roasting company.

Roast Profile: The rate, timing, temperature, and homogeneity of roast rate at various layers of the bean (external and internal). Roast profiling is critical for allowing the coffee’s own characteristics to be highlighted as well as for blending different coffees to be used as espresso, or as brewed coffee.

Tryer: On a drum roaster, the tryer is the tool used to collect a sample of coffee to be observed by the roastmaster during roasting in order to track the profile and progress of the roast.

Light Roast: No oil, usually cinnamon, or a little darker in color. Lighter body, more flavor of origin and acidity comes through.

Medium Roast: Very little to no oil present. Milk chocolate in color, has added depth of body at the cost of some acidity, and possibly at the cost of some origin characteristics.

Dark Roast: Dark, almost black, with ample amounts of oil present on the surface. Almost, or all origin characteristics are gone, the body is beginning to decrease, the flavor is thin, and usually tastes of the roast, including charcoal, bitter flavors, and very low acidity.

First Crack: A roasting term. The coffee bean’s first expansion as vaporized moisture escapes. The coffee been expands to nearly double its volumetric size, and a popping sound almost like popping popcorn can be heard.

Second Crack: The coffee bean’s second expansion as vaporized moisture is released, and the bean structure itself begins to fracture. Many of the flavors of origin are burned off during second crack, while body is increased, and acidity becomes more muted, or possibly lacking entirely. A noise sounding much like rice cereal in milk can be heard as the second crack develops.