Ever feel like this guy?
Do you know how much caffeine is in your cup of coffee? It can be anywhere from 40 to 200 mg of caffeine depending on the coffee to water ratio. Lots of people have different theories on just how much coffee goes into their specific blend of java, but science tells us that there is a fool proof way to know.
Most folks generally believe that a darker roast has more caffeine. Not so! It really doesn't matter what the roast quality is, light, medium or dark. What matters is how much coffee you're measuring out into that little white filter that will eventually end up in your favorite mug.
You see, with a dark roast (and this is possibly where the myth originated) the beans tend to be bigger. This is because, the darker you roast it the more water is roasted out and the fluffier the bean gets. As the water is roasted out of the bean, the bean swells and becomes larger than say, a medium roast bean. Now, when you go to grind these dark beans you'll notice that you'll need to grind a few more than normal to get the amount you're looking for to make your usual brew. Therefore, when you use more beans, the more caffeine you'll get.
So while your normal Cup of Joe may make you a little more wired than your friend's regular brew, it’s simply because you had more grounds to that filter than she did.
Voila! Myth Busted!
FROM YOUR FRIENDS AT NORTH POLE COFFEE ROASTING
National Coffee Association 2013 Consumption Survey
Annual Review of Medicine: Clinical Pharmacology of Caffeine.
International Coffee Organization: Caffeine
Specialty Coffee Association of America: Decaffeination