The common way to describe coffee roast levels is by the color of the roasted beans ranging from light to dark. As coffee beans absorb heat in the roasting process their color becomes darker and oils appear on the surface of the beans at higher temperatures.
- Light Roast: light brown in color with a light body and no oil in the surface of the beans. Light roast also contains most of the caffeine from the coffee bean.
- Medium Roast: these beans are medium brown in color with more body than light roast. Similar to the light roast they have no oil on the surface of the bean. However, medium roast beans lack the grainy taste found in the light roast exhibiting a more balanced flavor, aroma, and acidity.
- Dark Roast: these beans are dark in color like chocolate or some can be almost black. They have a sheen of oil on the surface. The coffee flavor will generally be bitter, smoky, or even taste burnt.