One of the most common coffee myths is that dark roast coffee has more caffeine than light roast because it tastes stronger and bolder. Others claim the opposite–that light roast is more caffeinated because it retains more of the bean's natural properties. So, what's the truth? Let's break it down!
Does roast level affect caffeine?
The idea that roast level dramatically changes caffeine content is a myth. The difference between light and dark roasts in terms of caffeine is actually quire small. Here's why:
- Caffeine is stable during roasting – It doesn't burn off like other volatile compounds, so both light and dark roasts retain roughly the same amount of caffeine per bean.
- Weight vs volume matters – Dark roasts lose more moisture and mass during roasting, making each bean lighter. That means if you measure coffee by weight (grams), both roasts have nearly the same caffeine. However, if you measure by volume (scoops), light roast will have slightly more caffeine since the beans are denser.
- Taste can be deceiving – Dark roast has a bolder, more intense taste, which makes many people believe it has more caffeine, but that's just the result of the roasting process altering the flavor compounds–not caffeine levels.
What should you drink for more caffeine?
If you want a caffeine boost, it's not about roast level–it's about:
- Coffee-to-water ratio – More coffee = more caffeine!
- Type of beans – Some coffee varieties (like Robusta) naturally have way more caffeine than others.
- Brewing method – Really? How? I'm shocked after this information too, let's get to the bottom of this!
How brewing methods impact caffeine
The brewing method itself doesn't change the caffeine content in the beans, but it does affect how much caffeine ends up in your cup.
The total caffeine you consume depends on:
- Coffee-to-water ratio again.
- Brew time - The longer coffee is in contact with water, the more caffeine is extracted.
- Grind size & extraction - A finer grind (like espresso) extracts faster but in a smaller volume, while a coarser grind (like french press) extracts slower but in a larger volume.
Espresso → small, but concentrated
Drip Coffee → More caffeine overall due to volume
French Press → Longer brew time extracts more caffeine
Cold Brew → Uses more coffee & steeps for hours, so it's very strong!
So, while the beans have the same caffeine content, the brewing process determines how much caffeine ends up in your cup.
Want to learn more about brewing? Check out: Coffee Brewing Tips: Get the best out of your beans
The Final Verdict: Light vs Dark roast caffeine
If you weigh your coffee, there's almost no difference in caffeine between light and dark roast. If you scoop your coffee, light roast might give you a tiny bit more caffeine per cup–but the difference is so small that it won't impact your energy levels in any noticeable way.
Try it yourself!
Next time you grab a coffee, test how it affects you. Do you feel a bigger caffeine hit from lighr or dark roast? Or does it come down to how much you drink?
Stay tuned for more myth-busting posts!
Find your perfect cup with our Guide to roast profiles
More coffee Science? Read: Where does coffee get its flavor from?
