How are Light Roast Coffee and Dark Roast Coffee Different?

Coffee is one of the most popular drinks in the world. Whether you’re stopping by the drive-thru window of your favorite coffee shop for a mid-afternoon pick-me-up or brewing a cup at home to start your day, there are countless combinations and flavors to make your coffee one-of-a-kind. Aside from decaf or regular, choosing your perfect blend depends on how you prefer your roast: light or dark?

Light Roast Coffee vs. Dark Roast Coffee

• How they are roasted
• The Caffeine Difference
• The Taste

How are Coffee Beans Roasted? 

Although you’ll hear the terms light and dark roast coffee across the industry, there are very few standards that determine what type of roast falls into which category. Thankfully, it’s relatively easy to judge by sight, and roasters typically stick to four general categories for their beans:

• Light
• Medium
• Medium-dark
• Dark roast coffee

Understanding the differences between light roast coffee and dark roast coffee begins with how the beans are prepared. Before being turned into the coffee that gets poured into your cup, the beans go through an extensive process to highlight the flavors we’ve come to know and love.

How coffee beans are roasted and the subsequent type of roast you get impacts the taste, quality, and strength of the coffee. Although the type and quality of the beans are essential, even the slightest change in the roasting process can drastically change the flavor of your favorite drink.

Coffee beans have interesting anatomy. Unlike what you’re used to seeing bagged at your favorite coffee shop, coffee beans begin green, a term that describes the beans' state after picking but before roasting. After they’re harvested, coffee beans are quite the opposite of what you would imagine. Instead of being fragrant and toasted in color, they're soft, spongy, and may smell like grass. You can store coffee beans in this green state without losing taste or quality.

3 Stages of Roasting Coffee Beans

• Drying
• Yellowing
• Browning

The drying stage occurs when heat is added to the beans, causing the water content to decrease. This is when the first of hundreds of chemical reactions occur, each essential to creating delicious roasted coffee. The second stage, also known as yellowing, refers to the color change the beans undergo as the heat exposure continues.

Although the first two stages of roasting coffee are essential, the chemical reactions that occur during stage three, or the browning stage, are where the magic happens. The browning stage is also where you get light or dark roast coffee. The Maillard reaction, Strecker degradation, and caramelization are the chemical reactions that help give the beans the distinct flavors associated with light and dark roast coffee. 

The Maillard Reaction and Roasting

Although you may not recognize it by name, the Maillard reaction is something we’re all familiar with. As heat is applied to certain foods, the sugars and amino acids undergo a chemical reaction that gives the foods their distinct brown coloring. Popular examples include marshmallows, bread, and cookies.

The Maillard reaction varies in length and begins when the beans reach roughly 300°F. The browning stage ends when the increase in pressure causes the beans to experience their first crack. If you listen carefully, you can hear the popping noises in addition to seeing the beans become darker.

Once all the water has evaporated inside the coffee beans, they experience a second crack and continue darkening in color. The longer the beans are left to heat, the more sugars will break down, giving the finished coffee a bittersweet taste with decreased acidity. For light roast coffee, roasters remove the beans somewhere between the first and second crack, while dark roast coffee is left past the second crack.

What’s the Caffeine Difference Between Light Roast Coffee and Dark Roast Coffee?

It’s easy to believe that light roast coffee contains less caffeine than its darker counterpart. The deep flavors, intense aromas, and dark colors make it feel like dark roast coffee packs a punch. However, most studies have shown that each roast has roughly the same amount of caffeine or that light roast coffee is a bit stronger.

As coffee is roasted, the water evaporates, and the beans become lighter in weight and larger in size. If you measure by the scoop, you’ll get more beans with light roast coffee because they’re smaller, allowing a slightly larger dose of caffeine. The bottom line is that if you’re looking for more of a jolt, you’re better off choosing your cup based on the type of drink rather than the roast. (Need a bit of a buzz? Choose cold brew. The ratio of beans to water and extended brewing time will give you the most bang for your buck!)

What Does Dark Roast Coffee Taste Like?

As coffee beans are roasted, the beans increase in taste to become stronger and more robust than you’ll find in light roast coffee. If you’re looking to enjoy the subtle flavors of the various regions of origin, you’ll want to stick with something lighter.

When it comes to drinking dark roast coffee, don't believe the myth that you’ll be sipping a cup of thick, black, burnt-tasting beans. When roasted correctly, fresh, high-quality coffee beans will leave a bold taste in your mouth that is full of body, a tad bit sweet, and usually pairs well with dark chocolate. If you order a dark roast and notice any hint of flavor that tastes burnt, it’s likely due to inexperienced roasting, not the fault of the beans.

Which Coffee Roast Is Best?

Choosing between dark and light roast coffee is a decision as unique as people themselves. The time of day, flavor choices, additions of cream and sugar, and the type of drink you prefer all have an immense impact on which roast will suit your needs.

Here are a few ways we like to mix and match our flavors to get the best coffee possible:

• A boost of energy: For a much-needed pick-me-up, choose something like a cold brew or add a shot of blonde espresso to your favorite coffee drink.
• An after-dinner treat: A dark roast coffee, with its rich flavors and slight sweetness, makes a great pairing for your favorite dessert.

Something for everyone: Nearly every coffee roaster has a house blend, and these are some of our favorites for pleasing larger groups with varying taste preferences. House blends tend to be easy to drink, mellow in flavor, and mix well with any type of flavored creamer.

Added flavor: If you want to add a bit of surprise to your coffee, choose a roast with added flavor, such as an Irish cream, pumpkin spice, or chocolate.

No matter how you choose to enjoy your coffee, you’ll be better equipped than ever to find the roast that’s perfect for you. Whether you prefer a light roast coffee, flavorful dark roast coffee cold brew, or a sweet holiday treat, there’s always something for everyone at Stone Street Coffee.