Light roasts are light brown in color. There isn't any oil on the surface, and the origin of the beans is the most distinct.
Medium roasts are medium brown in color. This roast is slightly sweeter than light roasts, and it has a balanced flavor, aroma, and acidity.
Medium-dark roasts have a rich, darker color with some oil on the surface. There is a bittersweet aftertaste. The flavor and aroma emerge while the acidity disappears completely.
Dark roasts have a shiny, black color with an oily surface. There is a significant amount of bitterness. The origin flavor is gone, and the flavor of the roasting process comes out the most.