The Craft of Roasting
The process from green to roasted beans is a quick evolution. Over a period of roughly 15 minutes, the green coffee loses moisture, turns yellow and “pops” open, much like popcorn. As it does so, the bean nearly doubles in size, and begins to assume the very light tan color of lightly roasted coffee. Once this stage is achieved, about 8 minutes into the roast, the heat source is turned down and the coffee rapidly darkens in color. When the desired degree of roast has been achieved, the roasting process either is stopped by quenching the beans (using a brief spray of water followed by cooling air) or by just air alone.
Light brown, dry surface
Grainy taste, distinct sour or acidic tones
Medium brown, dry surface with some wrinkles, flat color
Typical commercial roast, no grain flavor, some acidity, richer tones than cinnamon, flavor profile not fully developed
Darker, richer brown, oil patches on smooth surface, no wrinkles
Slight, roasted, bittersweet tang, less acidity than American roast, full profile of coffee flavor
Dark brown, oily surface
Definite bittersweet taste, all acidity tones gone
Darker brown, oily surface.
Rich and bittersweet in flavor
Very dark brown, almost black, very shiny, oily surface
Dark caramel tones, all acidity tones gone