This article originally published in The Sturbridge Times, April 2020 By Elvis Dyer, Owner/Roaster, Sturbridge Coffee Roasters
Why do coffees taste so much different? Some may be bright and fruity while others are dark and chocolatey. Coffees can taste more intense than others, not necessarily because of the origin or climate the beans grew in, or how the beans are processed (although these factors do play a part). The most noticeable flavor of the coffee is usually determined by the roast.
Roasting beans is an art and science. Each roaster uses their own temperatures, measurements and methodologies. The goal in coffee roasting is to enhance the qualities of the green coffee beans and to develop them to their fullest potential. Each bean has its own unique flavor profile that the roaster enhances during the process. For example, bringing out a citric flavor or enhancing the chocolate notes. Generally, roasters will bring the beans to roasting levels such as:
Light Roast: This roast is light brown in color with no oil on the surface of these beans because they are not roasted long enough for the oils to break through to the surface.
Medium Roast: This roast is medium brown in color with a stronger flavor and a non to light-oily surface.
Dark Roast: produces shiny black beans with an oily surface and a pronounced bitterness. The darker the roast, the less acidity will be found in the coffee beverage. Dark roast coffees run from slightly dark to charred.
Light and dark roasts are the first indicator as to what your coffee is going to taste like.
Light roasted coffee is processed with less heat than a dark roast. During the roasting process, the process forces water and moisture out of the bean by evaporation. Since light roasted beans aren’t left in the roasting machine for as long as dark roasted beans, they’re left with more moisture inside the bean, rendering it denser. This denser coffee bean provides more caffeine, more brightness (sometimes called “acidity,” but not actually chemically acidic), and more fruit-forward, herbal flavors. There is more complexity in a light roast coffee, however the body is thinner than that of a dark roast. And yes, there is more caffeine in a light roast, which is why you often see light roast “Breakfast Blends” to give you the morning pick me up needed.
Dark roast coffee beans are roasted for a longer time and often at a higher temperature. During this process, the beans lose more moisture, making them less dense, less caffeinated, and more single-note in flavor. The complexities found in a lighter roast coffee start to disappear the longer the beans are roasted.
Dark roast coffee is often described as having flavors reminiscent of caramel, roasted nuts, coffee and graham crackers. Since dark roast are roasted long enough to develop their oils and bring them to the surface, the body of your coffee will be thicker.
The best way to truly appreciate the differences between a light roast and a darker roast is to sample each and figure out what you like more. A dark roast of a certain country does not mean it will have a bolder flavor. The flavor could be totally different and experimenting with different brews is the only way to truly taste the differences.
If you’re trying to figure out which roast is for you, generally, light roast coffees have a thinner body and more delicate flavors. Dark roast coffees are more full-bodied with bolder and more straight-forward flavors.
And remember, the flavor of a coffee bean peaks within a few days and decreases rapidly when exposed to air, light and humidity. We recommend you purchase whole beans and fresh-grind as needed and store them in a cool, dry place in a container with a tight-closing lid. When brewing, make sure your equipment is completely clean, as old coffee oils can impart a bitter flavor to a new brew.
