The Stages of Coffee Roasting

Stage Unroasted Cinnamon American Full City Vienna Espresso French Italian
Raw bean is 12% water by mass. Volatile vapors cause bean to expand. Bean is still expanding. Acidity content higher than sugar. Bean at max expansion.
Balance of acids and sugars.
More gasses are lost. Aromas decrease. Sugars caramelize. Acids radically decrease. Sugars caramelize. Bean loses characteristic coffee flavor.
Mass Loss 0.0% 13.0% 14.0% 16.5% 17.0% 18.0% 19.0% 20.0%
Degrees F
Room Temp. 380-400 400-435 435-445 445-455 455-465 465-475 475-480
Bean Appearance Green and
Light brown. Smells of baking bread. Darker brown. Larger in size Bean chips begin to fly off. Smooth and brown. Oil is visible. Dark brown. Beans have oil on them. Black and oily. Dark black. Very oily. Burnt smell. Black, oil is dried off.