How Much Caffeine Is Really in Your Coffee Beans?

We settle the age-old question on everybody's, er, grind

Anybody who's ever pulled an all-nighter knows all too well the feeling of throwing back cups of stomach-scorching, extra-extra-dark coffee just to get through the night—after all, the dark roast has more caffeine, right?

Well, it's actually a contentious debate. Many casual java sippers assume darker beans' richer, more intense flavor means an extra buzz, while Chemex-faithful connoisseurs argue lighter beans are the way to go when you need a wake-up call. But, believe it or not, both these schools of thought are actually false. The truth?

Dark and light roasts contain virtually the same amount of caffeine.

So why does the argument that lighter coffee is more potent keep floating around like clouds in our, well, coffee?

Lighter-roast advocates usually defend their stance by claiming that the longer the beans roast, the more caffeine burns off of them. But really, the longer you roast your coffee, the more water weight—not caffeine—it loses.

The beans also puff up slightly during the process, meaning that darker roasts come out both bigger and lighter (aka less dense) than their less-toasted counterparts. So in the end, lighter roasts simply just pack more coffee per scoop into your morning brew, hence the myth that they're the ones that'll give you an extra jolt. But, according to most coffee roasters, that small amount of additional beans is pretty negligible.

The moral of the story? We should probably all just get a little more sleep.