Does dark roast coffee have less caffeine?
Many people have heard dark roast coffee has less caffeine. The truth is the roasting process has minimal effect on the caffeine levels. Coffee, however, does expand and gets lighter in weight the longer it's roasted. If you measure your coffee with a scoop, you will have slightly less dark roast coffee beans or grinds in your scoop, meaning slightly less caffeine. If you measure by weight, you will have somewhat more dark roasted coffee beans or grinds than you would have from a lighter roast, which means slightly more caffeine per weight.
If you are concerned about not getting the same amount of caffeine in your dark roast, then worry no more. The roasting process has minimal impact on the caffeine in the coffee. How you measure it is more important. If you're ever in doubt, remember, just drink more coffee.