Light Roast vs. Dark Roast

Does one really have more Caffeine?

Have you ever heard someone say light roast coffee packs more caffeine than dark roast? It's a question that comes up often, and if you’ve ever found yourself wondering if that’s true, you’re in the right place. Let’s break it down together, because understanding your coffee is almost as satisfying as drinking it.

Does Roasting Change Caffeine Levels?

First things first: caffeine is a remarkably stable compound. During the roasting process, coffee beans are heated to develop flavor and aroma. Roasting temperatures usually range between 180°C and 250°C (356°F to 482°F). Even though this sounds intense, caffeine holds its ground. It doesn’t break down or evaporate unless temperatures exceed 285°C (545°F)—and coffee roasting never goes that far.

So, roast level doesn’t really affect caffeine content when you compare coffee by weight. A gram of light roast coffee has about the same caffeine as a gram of dark roast. That’s good news, right?

Where the Difference Comes In: Volume vs. Weight

Here’s where things get interesting. Light roast beans are denser because they’ve been roasted for a shorter amount of time, so they retain more of their original structure. Dark roast beans, on the other hand, lose water content and expand during roasting. This makes them less dense and slightly larger.

If you’re scooping your coffee by volume—say, with a tablespoon—you’ll get more caffeine from light roast because you’re packing in more bean density per scoop. Dark roast beans take up more space, so a scoop of those contains fewer beans and, therefore, less caffeine.

But if you measure your coffee by weight, there’s virtually no difference in caffeine content between the two roasts.

What Science Says About Caffeine and Roasting

Let’s back this up with a little science:

• A study published in Scientific Reports found that while light and dark roasts contain similar amounts of caffeine by weight, light roasts tend to extract more caffeine per brew when measured by volume.

• Research from Berry College notes that roasting affects how porous the beans become, which can influence caffeine extraction during brewing. Light roasts may hold onto their caffeine better during extraction, giving you a slight edge in caffeine content.

What Does This Mean for Your Cup?

So, what should you do with all this information? Here’s the takeaway:

• If you want the most caffeine per cup and you’re scooping your coffee, go for a light roast. Its higher bean density will give you a little extra kick.

• If you’re weighing your coffee—or just prefer the bolder, richer flavor of a dark roast—you’re not missing out on much caffeine.

At Brewed Gratitude, we believe coffee is more than just a beverage—it’s a daily ritual, a small moment of joy in a busy world. Whether you love the smooth complexity of a light roast or the bold intensity of a dark roast, your caffeine fix is safe either way.

Next time someone claims light roast coffee will give them superpowers, you can confidently say, “Well, kind of... but it’s really about how you measure it.”

Now, go pour yourself another cup. You’ve earned it.