Are the first two phases of the roast endothermic or exothermic?

The correct answer is that the first two phases of the roast are endothermic. During these initial stages, the coffee beans absorb heat from the environment. In the first phase, known as the drying phase, moisture within the beans evaporates, requiring energy input, which is typical of an endothermic process. As the temperature rises, the coffee beans continue to undergo physical and chemical changes, still requiring heat to facilitate these transformations.

In the context of roasting, endothermic processes occur when energy is absorbed to break bonds and initiate reactions without producing heat. This contrasts with exothermic processes, where energy is released. The nature of these first two phases emphasizes the need for significant energy input to drive the changes in moisture content and prepare the beans for further roasting stages.