NO TWO COFFEES TASTE EXACTLY THE SAME.
Some are bright, floral and fruity. Others are deep, rich and robust. Countless factors contribute to the flavor in your cup, from the elevation at which the coffee beans were grown to the way they were processed.
Basically, there’s a lot to unpack when it comes to the flavor profile of coffee. But no single factor has a greater impact than how intensely the beans were roasted.
Light roasts and dark roasts exist at opposite ends of the flavor spectrum in coffee, while medium roast, unsurprisingly, offers something akin to a ‘best-of-both-worlds’ scenario. Let’s take a deeper dive into how—and why—light roast and dark roast coffee differ.
The Roasting Process
First and foremost, when comparing light and dark roast coffees, it’s important to remember that there’s no real difference between the beans themselves. All coffee beans start out green, and have a grassy, earthy aroma. What makes them ‘light’ or ‘dark’ is simply a result of how long they are roasted.
The longer coffee beans are roasted, the darker they get. Light roast coffee beans have a light brown, almost blonde tone, while dark roast coffee beans can be near-black in color. But darkening is not the only change that occurs during the roasting process.
As coffee beans roast and gradually darken, they lose moisture through evaporation. At a certain point, the oils within the coffee bean will also be forced out, which is why many dark roast coffee beans have an oily appearance, while light roast coffee beans appear drier.
The flavor changes too. The darker the beans get, the less of their original ‘origin’ flavor they retain, and the more flavor they take on from being roasted. For that reason, light roasts tend to have more unique and delicate flavors, which can vary greatly depending on the origins of the coffee; while dark roasts usually taste rich and—for lack of a better word—’roasty.’
When coffee beans are roasted, they start to pop or crack as they absorb heat and release moisture. The beans will start to crack at around 350 to 400 degrees Fahrenheit, which coffee roasters refer to as the ‘first crack.’
If the intent is to create a light roast, the beans are removed from heat after the first crack. Medium roast beans are usually allowed to heat to a temperature of about 440 degrees, and dark roast beans can get as hot as 460 to 480 degrees, by which point they will have cracked multiple times, released just about all of their moisture, and attained a deep, dark color.
Characteristics of Light Roast Coffee
What makes light roast coffees special is that they offer an opportunity to taste the origin flavor of the coffee. This is where other factors, like where the coffee was grown and how it was processed come into play. Coffees from different corners of the globe can have radically different flavors.
In a light roast coffee, a wide range of tasting notes may be apparent. In many cases, you may be able to pick up on fruity or floral notes, or the flavor profile may be more earthy or nutty. People tend to describe the flavor of light roast coffee as ‘brighter’ and more complex than dark roast coffee.
Coffee made from light roast beans will also have a thinner body, which is to say that the viscosity or actual thickness of the liquid is less than that of a dark roast. Light roasts also often (but not always) have a bit more acidity to their flavor profile.
Characteristics of Dark Roast Coffee
When asked to describe the flavor of a dark roast coffee, most people use words like ‘rich,’ ‘robust’ and ‘bold.’ As coffee beans roast and darken, they gradually lose their original flavor and take on the flavor of the roasting process itself.
Thus, dark roasts tend to have a stronger flavor, but one that is more one-note. Coffee beans that are roasted somewhere in the medium-dark range tend to have a bittersweet taste, while beans that are roasted to total darkness have more bitterness. It’s also possible to over-roast coffee beans, resulting in a brew that tastes burnt (an experience most of us have surely had at some time).
It’s also worth noting that—while there are many excellent dark roast coffees on the market—it’s common for low-end roasters to attempt to disguise poor quality coffee beans by roasting the holy heck out of them, eliminating what little original flavor they might have had and replacing it with something akin to charcoal.
Which Type of Coffee is Better?
To each his (or her) own! There’s a coffee out there for every palate, and different types of coffee are well suited to different uses and brewing methods.
Dark roasts are great for making espresso. They’re also great for anyone who simply prefers coffee that has a rich, robust, roasty flavor. Light roasts, on the other hand, are ideal for coffee connoisseurs who enjoy trying various single-origin coffees from around the world and picking out the unique flavors in each one.
Which Type of Coffee has More Caffeine?
Light roasts actually contain more caffeine than dark roasts. As coffee beans reach higher temperatures, they lose not only moisture, but also some of their caffeine content. So if you like a morning cup that gives you a real buzz, then light roasts are for you.
What Brewing Methods Are Best for Light and Dark Roasts?
There are countless ways to make a cup of coffee; and various roast levels are most compatible with certain coffee-making methods (although this by no means excludes you from using one method for varying roasts).
Generally speaking, a pour-over is the best way to prepare light roast coffee. Pour overs are known for really emphasizing the unique tasting notes in a cup of coffee, which is exactly where light roasts shine. When done correctly, a pour-over can reduce the acidity in coffee, which can make your light roast taste even better.
Medium roasts make for a great cold brew, so if you’re an iced coffee aficionado, look for coffee beans that are in the middle of the darkness spectrum.
For coffee beans that are closer to the medium-dark range, a French press is the way to go. French press coffee tends to be silky smooth and full-bodied, emphasizing the richness of darker coffees without too much bitterness.
If your coffee of choice is dark-dark, try an AeroPress. Using an ultra-fine filter, an AeroPress makes a smooth, rich cup of very strong coffee that can be used to make an espresso-style drink or diluted slightly to create something more like an Americano.