Does dark roast have more caffeine than light roast?

The belief that dark roast coffee is stronger or contains more caffeine is one of the most persistent myths in the coffee world. This misconception likely stems from the fact that dark roasts have a bolder, more intense flavor. Because dark roasts taste 'stronger,' many people assume they must also provide a bigger caffeine kick. In reality, the roasting process has very little impact on the total caffeine content of the bean.

When coffee is roasted, the beans lose moisture and expand in size. A light roast bean is denser and smaller than a dark roast bean. If you measure your coffee by volume—using a scoop, for example—you will fit more light roast beans into that scoop than dark roast beans. Because there is more coffee mass in the scoop, you will technically get more caffeine. However, if you measure your coffee by weight—which is the standard for specialty coffee—the caffeine content between light and dark roasts is virtually identical.

Caffeine is a remarkably stable molecule. It does not 'burn off' or evaporate during the roasting process, even at the high temperatures required for a dark roast. While there is a tiny amount of mass loss during roasting, it is not enough to significantly change the caffeine concentration of the final cup. Whether you choose a light, medium, or dark roast, the caffeine content will be determined primarily by the amount of coffee you use and the brewing method, not the roast level.

In practice, you should choose your roast based on the flavor profile you enjoy. Light roasts tend to highlight the unique characteristics of the origin, often featuring bright acidity and fruity or floral notes. Dark roasts emphasize the flavors developed during the roasting process, such as chocolate, caramel, nuts, or smoke. Don't worry about the caffeine; focus on finding a roast that makes your morning ritual more enjoyable.