The roasting process
Roasting brings out the aroma and flavor that is locked inside the green coffee beans. Beans are stored green, a state in which they can be kept without loss of quality or taste. A green bean has none of the characteristics of a roasted bean -- it is extremely hard and smells grassy.
Roasting causes chemical changes to take place as the beans are rapidly brought to very high temperatures. When they reach the peak of perfection, they are quickly cooled to stop the process. Roasted beans smell like coffee, and weigh less because the moisture has been roasted out. They are crunchy to the bite, ready to be ground and brewed.
Once roasted, however, they should be used as quickly as possible before the fresh roast flavor begins to diminish.
The stages of roasting
As the beans roast, they go through various stages. The stages are noted by both audio and visual cues. By watching and listening, one can determine the degree of roast that the bean has achieved.
Green coffee beans as they arrive at the dock. They can be stored for up to two years.
As beans roast, they lose water and increase in size.
A very light roast level, immediately before first crack. Light brown, toasted grain flavors with sharp acidic tones, almost tea-like in character.
New England Roast
Moderate light brown, still acidic but not bready, a traditional roast for Northeastern U.S. Coffee, at first crack.
Medium light brown, the traditional roast for the Eastern U.S. First crack ending.
Medium brown, the norm for most of the U.S., good for tasting the varietal character of a bean.
Full City Roast
Medium dark brown with occasional oil sheen, good for varietal character and bittersweet flavors. At the beginning of second crack.
Moderate dark brown with light surface oil, more bittersweet, caramel-y flavor, acidity muted. In the middle of second crack. Occasionally used for espresso blends.
Dark brown, shiny with oil, burnt undertones, acidity diminished. At the end of second crack. A popular roast for espresso blends.
Very dark brown and shiny, burnt tones become more distinct, acidity almost gone, thin body. The common roast for espresso blends.
Extremely dark brown, nearly black and very shiny, charcoal and tar tones dominate, flat, with thin body.