Many people think dark roast coffee is stronger than lighter roasts - but is that really true?
The answer is: it depends.
Let's break it down...
What Happens When Coffee is Roasted?
All coffee starts out as a green bean - actually a seed from the fruit of the coffee plant. In this raw form, it doesn't taste much like coffee at all. The flavour is grassy and unappealing.
Roasting it changes everything. As the beans heat up, they go through chemical changes:
- Sugars caramelise, making the coffee less sweet and more bitter
- The beans lose moisture and weight
- They expand in size and become less dense
- Carbon Dioxide and smoke are released
But here's the key point: caffeine doesn't break down during roasting. It stays stable throughout the process.
So, Does Dark Roast Have More Caffeine?
It depends on how you measure out your coffee.
By weight (e.g. using a scale): Dark roast has slightly more caffeine per gram, because the beans are less dense. So if you weigh out your coffee, you might get a stronger hit from a dark roast.
By volume (e.g. using a scoop): Dark roast has less caffeine per scoop, because the beans are bigger and lighter. A scoop of dark roast holds less caffeine than a scoop of light roast.
So the real answer is: dark roasted coffees aren't necessarily stronger - it depends on how you brew it.
What About Robusta Beans?
Another factor is the type of bean. Most high-quality coffees use Arabica beans, which are smoother and lower in caffeine.
However, many cheaper or commercial brands (especially instant coffee and espresso blends) include Robusta beans. These beans have much more caffeine than Arabica, but they're also more bitter and less refined in flavour.
The Bottom Line
Dark roast coffee isn't automatically stronger. If you want more caffeine, go by weight or choose a blend containing Robusta. But for smooth flavour and rich aroma, a quality Arabica roast - dark or medium - is the way to go.
