Dark Roast Vs. Light Roast
When it comes to making the choice of dark roast Vs. light roast, there are a few things that we might be thinking. We might be looking for a 'strong' coffee with plenty of caffeine to light the fuse on our day; or we might want something with those rich, dark, heavy flavours.
Here is the problem: when we see the word 'strong' on a bag of coffee, what does that mean?
Strong, when on a bag of coffee, is referring to the roast level of the beans, not the caffeine content. The two are not really related, although, they can be. Let us explain.
What is Roasting?
This is 'cooking' the green beans to change the flavours inside them. A lot of reactions happen inside the beans whilst roasting, and they happen at different temperatures. This is why we don't simply bundle the beans in the roaster, set it to 15-minutes at 180C and return when the timer pings.
There are things like the Maillard reaction that happen at 150C - where proteins are broken down into sugars (this is what happens when you brown meat). Different acids get broken down at different temperatures and also caramelisation beings to occur at 170C.
In order to reduce the unpleasant flavours, and unlock the great ones, we need to expertly manipulate the temperature over time and arrive at the bean's flavour 'sweet spot'. These manipulations can be different for different beans.
This is also why many commercial, mass-produced coffees have an overly bitter flavour. To mask inferior quality beans, they are over-roasted. Read more about this here: Arabica Vs. Robusta
Dark Roast Vs. Light Roast
Darker roasts (often labelled as 'strong' in supermarkets) are roasted further, developing those heavier, richer, nutty flavours at the expense of the lighter, sweeter, citrus notes. A lot of these flavours come down to the bean being used, so matching the roasting level to the ingredients is all part of the craft: you can't bring out flavours that just aren't there in the first place.
Lighter roasts are roasted to a lesser degree and tend to use beans that have great sweet, citrus, bright flavours. Typically, these would be brewed as filter or pour-over rather than espresso.
Read more about Filter Vs. Espresso for more on the differences and the impact of bean choice.
Dark Roast and Caffeine
So, after all that, does a 'strong' coffee (darker roast) have more caffeine than a lighter roast? Well, kinda... but not for the reason you would expect.
During roasting, water is evaporated from within the beans - like clothes in the dryer. That means the beans are losing weight. The further they are roasted, the more weight they lose. So, if you took 15 grams of green, un-roasted beans and 15 grams of dark roasted beans, you would have more roasted beans. They weigh less, but contain the same amount of coffee.
Green coffee beans destined for both light and dark roasting will contain similar amounts of caffeine. It's only when using the roasted beans that you get more caffeine from the darker roast, simply because you will be using more beans for the same weight of coffee. It's also possible that the roasting process opens up the beans more and allows more caffeine to be extracted, but this is not completely understood and is just a theory as of writing.
I Just Want a Strong Cup of Coffee
Robusta beans can have twice the caffeine content of Arabica, but is it a better tasting coffee?
Read our Arabica Vs. Robusta article for more on that.
If you're after a dark flavour with a real caffeine kick, you'd do better choosing a 'strong' (dark roasted) coffee. But, we'd recommend trying one of our freshly roasted dark options. Not just because this is our blog, our shop, and it would be strange to recommend someone else's coffee. But, because we have selected beans that work best for this level of roasting, and we have carefully manipulated the roasting process to get the greatest flavour from those beans.
In the end, dark roast Vs. light roast, the main thing we want is to enjoy the great taste of great coffee.
Written for Recent Beans by Jack Sheard, Freelance Writer - JACKEDCONTENT.COM