Does dark roast coffee have more caffeine?

Have you ever wondered if dark roast coffee beans have more caffeine than a light roast or a medium roast coffee simply because it tastes stronger? Well, the answer to this question might be a little more complicated than you think.

First, let’s debunk the myth once and for all. Coffee from the same variety, whether Robusta or Arabica, no matter the roast type, has the same amount of caffeine per bean. Period. The differences surface depending on how you measure your coffee - by bean, volume, weight or varietal. Remember that for later.

Secondly, what exactly is caffeine? Caffeine is a stimulant. It acts as a defense mechanism for the coffee plant. When the bugs on the plant get some caffeine in them it paralyzes them to prevent them from doing more harm to the plant.

In human beings, however, Caffeine blocks the effects of ‘Adenosine’. Adenosine is an important neurotransmitter, which makes us unwind and feel sleepy at night. Caffeine prevents adenosine from doing its job by attaching to the receptors and keeping us awake when we would otherwise feel sleepy.

Now let’s look at what happens during the roasting process

Raw coffee is put into a roaster for a period of time depending on what roast it’s aimed to be (dark roast, medium roast, or light roast) at a temperature over 204°C. This does nothing to the caffeine content in the beans as caffeine does not melt until it’s exposed to temperatures at over 235°C.

Coffee beans acquire their brown colour when they are roasted, however, they are green in their natural form. During the roasting process, the raw green beans’ colour changes to yellow, then light brown, medium brown and then finally dark brown and black. The longer the beans are roasted, the darker, bigger and lighter they become as they lose water.

This entails that, although the caffeine hasn’t changed in the coffee beans, a bean’s caffeine per volume decreases and caffeine per weight increases. Simply it means, that if you are making your morning coffee with one spoonful of dark roast, then you are getting less caffeine than you would if you put the exact same spoonful of light roast. Still complicated? Stick with us.

A lighter roast spends less time in the roasting process, compared to its darker counterpart. This results in the beans being less puffy than the dark roast and also slightly heavier. Since they are smaller, naturally more beans would fit in the same spoon of the lighter roast. You would therefore get a slightly stronger buzz from a light roast coffee brew than you would with the darker roast.

Should you decide to measure coffee by weight, a dark roast would have more beans for the same weight compared to a light roast. Do you recall what we asked you to remember from the beginning? Coffee from the same variety has exactly the same amount of caffeine per bean no matter the roast. Since you need the same amount of beans to get the same amount of caffeine, this is when the difference arises, when dark roasted beans are larger and lighter.

So, it takes a higher bean count (volume) of dark roast to equal the same weight as a light roast when you’re dosing to brew coffee. This happens as darker roasts have less mass and less water inside them, as more has evaporated during their longer roasting process.

Therefore, if you did make your morning cup of coffee by counting beans or weighing your coffee rather than keeping a tally of scoops, the dark roast will provide a stronger caffeine kick but you will also have a larger volume of coffee.

In Conclusion

Almost no one in the world has time to count their coffee beans every morning to brew the perfect cup. So, if you are looking to maximise the caffeine from your coffee, you can rely on the following rule of thumb: A light roast has more caffeine per scoop while a dark roast has more caffeine per gram.

However, if you prefer your coffee to have a slightly more full-bodied and charred taste rather than a sweeter, tangier, taste like the ones characteristic to light roasts, then you should go with your taste buds!

The differences between light and dark roasted coffees are significant in taste but the differences in caffeine levels are so slim that you probably wouldn’t even notice it.

Now go ahead and brew your delicious fresh coffee for your coffee cravings, may it be a French roast, an American roast, Continental roast, Italian roast, espresso roast, regular roast or whatever roast profile you enjoy the most in any brewing method you prefer.