It’s not easy to choose the ideal cup of coffee. You want a specific flavor, however, the coffee terminology can be confusing and it’s not always easy to tell what you’re going to get when you hear light, medium, and dark roast.
There is a lot of debate over what the best roast level is. Everyone has their own opinion and ultimately, the only one that matters is your own.
Let’s examine how the process of roasting works and how it affects the acidity, body, and overall taste of the coffee.
Coffee Roast Level
The term “roast level” is in reference to the time that the beans spend under the roasting process. Metrics like internal temperature of the beans and time they are roasted is directly related to their nomenclature.
In the roasting process, the beans undergo a chemical process known as the Maillard reaction. This is where they begin to absorb heat and release energy through cracking.
Cracking is actually a two-phase process. There is a first crack and a second crack in which the beans, as they are heated, expand and finally burst. This process releases moisture in the beans.
The time frame in which the beans are stopped in the roasting process and the number of cracks will determine the various roast levels: Light (1st crack), medium(2nd crack), or dark (burnt).
Factors Affected by Roast Level
This refers to the flavors the acids in the coffee can produce. There are over 30 kinds of acids in green coffee beans. Many of these acids can’t survive the roasting process.
Acidity has a huge impact on the overall taste of the coffee. The chlorogenic acids give breakfast blends their energetic and vibrant taste while the quinic acid will give dark roasts a nice smooth finish.
The body of the coffee describes how it feels in the mouth. Texture, weight, and the richness of the flavor are all due to the combination of the oils, acids, as well as the natural fibers that are in the coffee bean.
Different beans will have a different body when brewed. All of this is in direct relation to the type of beans and the acids in the coffee as well as the way that the coffee is roasted.
The taste of the coffee is due to the acidity and the body of the brewed coffee. There is a difference between taste and flavor. The taste denotes the sensory impact from the moment that the coffee touches the lips until the aftertaste of the coffee when it has been fully consumed.
There are five distinct taste sensations in humans: Sweet, Salty, Bitter, Sour, and Umami. All of these taste sensations are directly impacted by the roast level.
In comparison, light, medium, and dark roasts offer a variety of taste sensations that are as diverse as the individual coffee beans themselves.
Common Names of Light Roast: Light City, Cinnamon roast, Half City, and New England roast.
Light roasted beans undergo the shortest heating time. They will reach an internal temperature of 350 to 400 degrees Fahrenheit. The roasting process is stopped just as the beans begin to crack for the first time.
The beans are still a light brown color and are dense due to retaining more of their moisture. This causes them to be more caffeine-rich than darker roasts.
The act of lightly roasting will help to preserve more of the acids in the bean. The more acid that is present will help the coffee bean to retain more of it’s intrinsic flavors.
For example, Chlorogenic acids offer more vibrant flavors, but deteriorate more rapidly under heat. On the other hand, Quinic acid will continue to develop as the other acids begin to degrade. This is what gives a dark roast a clean finish.
The body of the coffee is reflective of the concentration of dissolved solids when it’s brewed. It’s more affected by the brewing method than how the beans are roasted.
For instance, light roasted beans are far less oily than darker beans. This results in a thinner overall texture.
Lighter roasts are more earthy than darker roasts. The taste is frequently described as wheat-like with unique notes that are affected by the origin of the particular bean that’s being used.
- Lighter brown color/light body
- No oil on the surface of the bean
- Pronounced acidity and a toasted grain taste
- Retains more caffeine
Common Names of Medium Roast: American Roast, Regular Roast, Breakfast Roast, City Roast.
A medium roast stops when the internal temperature of the bean reaches 427 degrees Fahrenheit or just before the second crack of the bean.
The beans are deeper in color and more of the oils are released. More moisture is lost and as a result there is less caffeine .
There is somewhat less acid in medium roast coffee. As a point of reference; on the pH scale a 0 is noted as acidic, water is neutral at 7, and alkaline or basic is a 12.
The pH of a medium roast will typically be around a 5.
The compounds and oils of the medium roast are more substantial. It can help to improve the complex notes of the flavor as they linger longer in the mouth and will lend more to the origins of the beans.
The flavors are more integral and developed and have a lower raw acidity than that of the lighter roasts. They are vibrant yet varied.
- More body than lighter roasts and medium brown in color
- There isn’t any oil on the surface of the bean
- The flavors are more balanced as well as the aroma and the acidity
- The caffeine is lower than that of the light roast beans
Common Names of Dark Roast: Italian Roast, French Roast, Continental Roast, Espresso Roast, New Orleans Roast, Spanish Roast.
Dark roasts are roasted for the longest period of time. The roasting is stopped when the beans reach the second crack. At this phase the beans are as dark as chocolate. They have an oilier sheen and interestingly enough, the least caffeine.
It can be confusing when selecting a darker roast. There are many flavors to select from and each one will have a different roasting time as well as a different flavor profile.
As we noted above the one acid that develops while being roasted in the quinic acid. This acid gives the darker roasts a cleaner finish, however, it’s also the one that can lead to an upset stomach for many coffee drinkers. It is found in the highest concentrations in the French Roast.
The oils that are released will add body to the coffee as it’s brewed. This is a thicker coffee that will have a syrupy consistency that will help to add flavor to the palate.
As more of the oils are released, they offer texture to the coffee and add depth to the flavor.
Compared to light roast coffees, dark roasts are more bold and smokey. Light roast coffee drinkers often refer to them as burnt or charred.
- As dark as chocolate and maybe even a black color
- Oil sheen on the beans that shows up sometimes in brewed coffee
- Darker roasts are more bitter and smokey or burnt flavored
- Ideal roast for espresso
- Significantly less caffeine
Remember that the level of the roast is only one of the many factors that will shape the flavor of the coffee. Select one that you prefer but never be afraid to try out the other roast levels. Remember, the roast levels and their differences are what make coffee beans unique.