One of the more frequent questions I got from clients at the coffee shop was about coffee roast levels and which one was best for them, for example should they get light, medium or dark roast? Or maybe somewhere in between.
I then would often give a brief explanation of the basics of roasting and how different coffees were better (or worse) at different roast levels. Therefore, in this article I am going to go over some basic coffee background information and then talk about the 3 main levels of coffee roasting and end with the answer to that popular question: WHAT ROAST LEVEL IS BEST?
We humans — as inventors, explorers, and originators — are quite ingenious, aren’t we? Especially of interest is when our need for nourishment becomes an overlap of food preparation melding with science and art. The results are fascinating! Through each of our own exposure, history, and well let’s face it — pure experiment or accident, we’ve developed our own unique preferences about taste, aroma, and flavor.
Human preferences really run the gamut and obviously in large part subjective, but at the heart of what sometimes seems to be subjective has a foundation in objective rationale of why we like something over something, or how it’s prepared some particular way over another way.
Consider for a moment that morning shot of coffee calling to you when you first open your eyes at home in the morning, or on your detour to the coffee shop take out before you head up the stairs or elevator to your workspace.
Did You Say Fruity?
Fruity… Not a word you might think of to describe a coffee bean, but surely coffee beans are fruits that grow on a tree, much like a lemon, apple, cherry, and obviously not like a strawberry near the ground. Coffee is more fruit-like than a strawberry in that case! The thing is, you can’t just bite into a coffee bean like you would a plum or strawberry, or simply peel and eat an orange.
With the fruit of the coffee bean, humans figured out that if you heat it up, roast it in some way, the result is a delicious beverage, eagerly anticipated and consumed daily for many of us. And, most people have preferences about their coffee, knowing what depth of smooth or sharpness of flavor of coffee they like over another. What some people may or may not realize is that our preferences come down to the differences in the coffee roast.
What we tend to call a coffee bean is in fact the seed of a cherry-like fruit. These coffee tree fruit berries grow in clusters and turn bright red when ripe. The skin of the coffee berries, called the exocarp, is a thick substance and tastes bitter. Underneath the exocarp is the coffee bean fruit, called the mesocarp, which has a texture like a grape and is very sweet tasting.
There is a heavy syrupy substance, called the parenchyma, which protects the beans, and the beans themselves are insulated with a thin layer called the endocarp. This endocarp protects two, bluish-green beans, which are surrounded by another layer of shield as the beans ripen into their perfect harvestability before picking and prepping for roasting.
The coffee green beans don’t have any of the characteristics of roasted beans, and they’re sponge like and soft, and smell earthy or grassy. Before roasting, coffee beans are typically stored green to help ensure no loss quality or taste. Once roasted, coffee beans need to be stored properly and used within a recommended amount of time to ensure quality.
Art And Science Of Coffee Unite!
Like many fruits (and vegetables), there are a variety of kinds of coffee beans and each comes with different flavor characteristics. The method used to roast a bean helps or hinders its natural palate profile. To elicit the highest potential of a coffee bean, the roasting process and tasty — and degree of caffeinated — outcome is the culmination of science meeting art and refining for the best roast result.
Heat temperature and time heated produce chemical changes to the amino acids and sugars present in the substance being heated. And that’s what makes the coffee bean roast something of great interest to your flavor (and perhaps known caffeine effect) preference palate as you choose what kind of coffee to consume.
Most coffee is roasted commercially on a rather grand scale, however small-scale commercial roasting has increased quite a bit lately. And, some coffee drinkers are roasting coffee at home as a hobby and to experiment with flavor profiles of different beans, and also to guarantee the freshest possible roast.
Roasting allows the flavors and aromas trapped inside harvested coffee beans to surface. Blending art and science, coffee bean roasting causes chemical reactions as they beans are brought to high temperatures and then quickly cooled to stop the roasting process. Roasted beans have that familiar coffee smell and are crunchy to the bit, and because their moisture has been roasted out of them, they weigh less. Grinding and brewing follow. But first, what’s in a roasting and why and how do they vary?
Roasting Varieties 101
There are three main categories of roasts, and while there’s no particular industry standard in the definitions, these explanations and generalizations below hold pretty true. Understanding each coffee roast type can inform your decisions about your coffee choice or provide guided opportunity to explore some roasts you hadn’t considered or may help you understand why you already prefer whatever coffee you can’t help but return to time and again. Flavor aside, if you learn anything today about roasting, it may be this counterintuitive fact about roasts: The caffeine level diminishes as the roast gets darker.
Light Roast Coffee
Light roast coffee beans are the most common variety of coffee roast. A light roast coffee bean undergoes roasting until what’s called the “first crack”, which is the first stage of coffee bean expansion, which actually alters the structure of the bean. Light roasted beans reach an internal temperature of 180°C – 205°C (356°F – 401°F), where at near 205°C/401°F, the beans pop and expand, considered the beans’ first crack.
So, a light roast generally means a coffee that has not been roasted beyond the first crack or just at the very end. These now lightly roasted beans look pale and dry, and when used for coffee, there is less body and boldness, higher acidity yet also more of a varied flavor profile.
Light brown to your eye, light roast is often preferred as a mild coffee variety. There’s no oil on the bean surface because of their limited roasting time and the oils haven’t broken through yet. Lighter roasts tend to be described as having fragrant, floral and fruity coffee notes, with a mild body. You may be surprised to learn that lighter roasts have slightly more caffeine than the other roasts.
Medium Roast Coffee
Medium roast coffee beans offer a more full-bodied flavor and are often used for regular or breakfast roasts. Medium roasted beans have reached internal temperatures between 210°C (410°F) and 220°C (428°F), which is after the end of the first crack and right before the start of the second crack. While the beans are still dry and mostly non-oily like the light roast beans, the medium roast beans are medium brown in color and offer a sweetness that comes from the heat and roasting that causes a bit of caramelizing.
The flavor is a little stronger. The acidity is lower and the body of the coffee gives a fuller profile. Medium roast compresses flavor, which causes some bitterness or slight bittersweet aftertaste to be more distinct. Medium roast is one of the most preferred roasts in the United States.
Dark Roast Coffee
Coffee beans that are considered dark or full roast are in the roasting until what’s called the “second crack”. The roasted beans have been processed into the beginning or middle of the second crack — around 225°C (437°F) to 230°C (446°F). It’s at these temperatures where the coffee beans’ aromas and flavors are prominent and gives a bold body flavor.
Some beans roasted to this level even take on a somewhat spicy profile. A noticeable visual difference is that the beans start to be coated with an oily polish from the roasting process.
Dark roasts definitely have a thicker “roasted” quality in their flavor profile and can run from slightly dark to nearly charred. Dark roast beans are shiny black beans, coated with an oily surface, and to the bite — a noticeable bitterness.
Dark and full roasts have less caffeine concentration than lighter roasts. Note that some people misunderstand espresso as being a dark or full roast when in fact espresso is just a brewing method and not a type of roast
So What Roast Level Is Best?
Another way to think about the different coffee roasts is that in lighter roasts you’re going to have the roasted beans exhibiting more of their origin character, like the natural flavors created by the bean’s own variety, soil, altitude and weather. With more roasting and as the beans darken, those origin flavors are obscured by the new roasting-induced flavors. For darker roasts, the actual roasted flavor may be so prominent that you can’t even decipher anything about the origin of the pre-roasted beans.
Medium and dark roasts have lower moisture and oil content. Some people have become accustomed to believing that darker, more bitter, roasty-flavored coffee is better for some reason, when in fact the roasting process has gotten rid of a lot a bean’s flavor profile. When you go for something a bit lighter, you may just be surprised that it is naturally a bit sweeter and creamier just as is.
What really matter is what you like. The point here though is perhaps try something new in a roast you don’t typically consume or haven’t tried at all.
Coffee Roasting Mastery Is Not Easy
Successfully roasting coffee beans is not easy. The roaster has to have the ability to read the beans and make split-second timing decisions. A perfect batch of roasted beans and a ruined batch of roasted (read burned!) beans can happen with a blink of an eye. A coffee roast continues to darken until removed from its heat source.
Coffee also becomes darker as it ages, so color alone is not reliable as a roast basis. Roasters tend to find the most success with experience using a blend of information about temperature, smell, color, and sound to gauge the roasting process.
So the next time you pick up your beloved brew, whether it is fondly known as your: Joe, Jitter Juice, Liquid Gold, High Octane, Wakey Juice, Java, Morning Jolt, Liquid Energy, Cupped Lighting, Heavenly Brew, Rocket Fuel, or whatever you call it, appreciate all the roast options at your disposal and the mastery of what you hold in your hand.