Exercise 1 - solution

In order of increasing temperature:
1. Drying: about 165 C. Water is driven off.
2. Exothermic point: about 175 C. The roast changes from absorbing heat to releasing heat, so the beans start heating themselves.
3. First crack: about 196 C. After several minutes the beans pop or crack.
4. Second crack: about 224-225 C. A few more minutes later; oils begin to surface on darker roasts.