Light, Medium or Dark Roast?

Roasting coffee transforms the chemical and physical properties of green coffee beans into roasted coffee products.

The roasting process is what produces the characteristic flavor of coffee by causing the green coffee beans to change in taste. Unroasted beans contain similar if not higher levels of acids, proteins, sugars, and caffeine as those that have been roasted, but lack the taste of roasted coffee beans due to the Maillard (a chemical reaction that gives brown food its distinct flavour) and other chemical reactions that occur during roasting.

Flavour

At lighter roasts, the coffee will exhibit more of its "origin character"—the flavours created by its variety, processing, altitude, soil content, and weather conditions in the location where it was grown.

As the beans darken to a deep brown, the origin flavors of the bean are eclipsed by the flavours created by the roasting process itself. At darker roasts, the "roast flavour" is so dominant that it can be difficult to distinguish the origin of the beans used in the roast.

Green coffee contains many different types of acids, some of which are pleasant to taste and some that are not. Of particular importance to the roaster are the chlorogenic acids (CGAs). One of the key goals of roasting is to break down these unpleasant acids.

Below, roast levels and their respective flavors are described. These are qualitative descriptions and thus subjective.

coffee roast flavours