What is the primary purpose of roasting coffee beans?

The primary purpose of roasting coffee beans is to develop the flavor and aroma compounds. During the roasting process, the heat causes a series of chemical reactions known as the Maillard reaction and caramelization, which transform the green coffee beans into aromatic, flavorful brown coffee beans. These reactions enhance the complexity of the flavors and aromas that contribute to the overall sensory experience of coffee.

While roasting does darken the color of the beans, this is a by-product of the heat applied during roasting rather than the central goal of the process. Roasting does not significantly increase the caffeine content of the beans; the caffeine level remains stable after roasting, although the perception of strength can change. Lastly, preserving the green color of the beans is not a purpose of roasting; in fact, the roasting process completely alters their color and transforms them into the beans that are ultimately brewed into coffee.