The INSIDER Summary:

By volume, there's more caffeine in light roast coffee than in dark roast coffee.

This is because dark roast coffee beans have been roasted for longer and often become over roasted or even burnt.

When coffee beans are burnt they lose attributes like flavor and caffeine content.



You stayed out way later than you had planned last night, and this morning has been rough.

So when it comes time to choose a coffee, you pick a strong dark roast from your office's selection.

Turns out you might want to rethink that decision. According to Thomas Hartocollis, co-founder of coffee shop Roasting Plant, by volume, there's actually more caffeine in light roast coffee than there is in dark roast coffee.

Here's why.

By the cup, there's little difference in caffeine content between light and dark roasts.

Darker is not stronger. Maria Fernanda Gonzalez / Unsplash

Like its name suggests, dark roast coffee is roasted for longer than light roast coffee. Hartocollis says that roasting coffee beans for this long results in the beans turning black and oily, which, in many expert opinions, means the beans have been over roasted or burned.

And just like food that's been burned, coffee beans that have been burned lose flavor and other attributes, like caffeine content, Hartocollis says. In other words, flavor and caffeine content decrease as the coffee gets darker.

But it's important to note that this difference in caffeine content is only true in terms of volume — caffeine content relative to bean size. By the cup, light and dark roast coffee contain the same amount of caffeine, Hartocollis says.

Many people mistake dark roast's more intense taste to mean it has more caffeine.

Next time you're really in need of a caffeine jolt, go for a light roast. Jason Briscoe/Unsplash

So why do so many people make the mistake of thinking that dark roast coffee is stronger?

Hartocollis says this is because dark roast coffee ends up having a stronger, more bitter taste than light roast coffee, because the beans have been roasted for a different amount of time at a different temperature. Some people mistake this more intense taste to mean a higher caffeine content, when really it means the opposite.

So stop worrying so much about caffeine content, and go for the roast that you like best.