The first stage is endothermic where the green beans are slowly dried to become a yellow color and where the beans begin to smell like toast or popcorn.
Often called the first crack, occurs at approximately 205 in which the bean, become a light brown color, and a weight loss of approximately 5%
The temperature rises from 205 to approximately 220, the color changes from light brown to medium brown and a weight loss of approximately 13%
The second step is followed by a second pyrolysis and the roast color is defined as medium-dark brown.
The beans take on an oily sheen.
Espresso potential is maximized in roasting.
The dark color of coffee is directly related to the caramel of sucrose in coffee.