It makes total sense why people think this. Dark roasts taste bolder, heavier, more intense. Surely that means more caffeine?

Not quite.

If you’ve ever assumed that darker roasts contain more caffeine, you’re not alone. It’s a belief that’s been passed around the coffee world for a long time. But the relationship between roast level and caffeine is far more nuanced and often misunderstood.

Light, medium and dark roasted coffees contain very similar (if not the same) amounts of caffeine. The roasting process changes flavour, aroma, and body, but caffeine remains relatively stable throughout.

As coffee roasters, we’re here to explain what affects how much caffeine ends up in your cup.

The myth: darker roast = more caffeine

Roast level doesn’t increase caffeine content. In fact, darker roasts often have slightly less caffeine than lighter roasts.

Why?

Caffeine is a relatively stable compound, but it does begin to break down the longer coffee is exposed to heat. Dark roasts spend more time in the roaster, which can reduce caffeine levels ever so slightly compared to lighter roasts.

It’s not a huge difference, but it’s enough to flip the assumption on its head.

So why do dark roasts taste “stronger”?

This is where flavour and caffeine get mixed up.

Dark roasts develop flavours like:

These flavours are bold and punchy, which our brains often interpret as “strong.” But strength of flavour isn’t the same thing as caffeine strength. Lighter roasts, on the other hand, tend to highlight:

They can taste lighter or more delicate, even though they often contain the same amount of caffeine.

What actually affects caffeine levels?

If you’re chasing caffeine (no judgement, we get it), here’s what really matters:

1. Coffee variety

Arabica generally has less caffeine than Robusta. Most specialty coffee roasters, including ours at GESHA Coffee Co., is Arabica because it’s chosen for flavour, not brute-force caffeine.

2. Brew method

Longer contact time = more caffeine extraction.
Think filter coffee, batch brew, or cold brew compared to a short espresso.

3. Dose and grind size

More coffee in, more caffeine out. Simple maths. Measuring by weight is more consistent than using a scoop, which can change how much caffeine ends up in your cup.

So… what coffee roast should you choose?

It’s simple. If you love dark roasts for their flavour, drink them. If you love light roasts for their brightness, also drink them!

But if caffeine is the goal, don’t rely on roast colour alone. Focus on:

And if you’re ever unsure, that’s what we’re here for.

Whether you’re brewing at home or running a café, we’re always happy to help you find a roast that tastes great and does what you need it to do.