Every steamy cup of coffee that we enjoy starts with a bean. However not every bean is created equal. Coffee beans go through the roasting process and this changes the way that coffee beans taste. The terms “light” and “dark” roast are often used by coffee lovers to describe their favorite cup.
But what exactly is the difference between light and dark roast coffee, and how does it happen? While there are many factors that can affect the final flavor of a cup of coffee, roasting impacts the flavor long before cream and sugar. The flavor of a coffee bean can be impacted by its farming process, but roasting a bean proves to be even more important.
The Roasting Process
After coffee beans are fermented they go through the drying process. When this is over, they are milled in order to have their remaining skin removed. At this stage, they are ready to be roasted. The roasting process involves the beans being heated and cooked for a duration of time, over which they become darker. Roasts range from light to medium to dark. Not only is their color affected, but their flavor too.
This is because the longer the beans cook, the more moisture they release. This causes the flavor differences between light and dark roast coffees. Light roasted beans retain more of the complex flavors that result from their cultivation. However, just because darker roasts are not as complex does not mean they taste worse.
The effects of roast time on coffee flavor
It can be hard to understand all the different terms used to describe a cup of coffee, but it is easy when you relate the flavor of a bean to its color. “Light and bright” is a good way to remember the taste of light roasts. Light roast coffees will be thinner bodied, with brighter or more unique flavor profiles.
Light roast beans retain more of their water during the roasting process than dark beans, thus they keep more of the flavors that come from the growing stage of their life. Good light roasts require a high-quality bean that doesn't need to be dark roasted to taste good.
Dark roasts come about when beans are left to roast longer, developing a darker color and a shinier exterior. Dark roast beans also have a more oily appearance and are lighter in weight. This is because they have expelled more water content at this point than light roasts do. Dark roast beans are also roasted long enough to develop a darker flavor profile. Dark roast beans are often described as tasting nutty or caramelized; this is because, unlike light roasts, they have had the time to cook and develop their flavor.
They also tend to taste less acidic and be heavier bodied than their light roasted counterparts. Dark roasting beans have long been a method to improve the flavor of lower-quality beans, but we still love them for their unique taste.
The difference between light and dark roast caffeine potency
It’s a long-standing debate whether dark or lighter roast coffee gives you more bang for your buck. Light and dark roast lovers alike tout that their roast provides them with the extra push they crave. The truth is, the difference between light and dark roasts doesn't extend to caffeine intake. Both light and dark roasts provide about the same dose of caffeine. When equal amounts of ground light and dark roast coffee are scaled out, the caffeine content in the resulting cups of coffee would be about the same. Rest assured that whatever your favorite roast is, you won’t need to fear missing out on your favorite caffeinated beverage.