Roast Levels
Just what does it all mean?!? Well, this is almost a trick question. Because we can take beans from the same plant variety and grow them in two different countries (or origins) and they will not taste the same. So there are many variables to coffee in general, plant variety, origin of growth, age and processing method, roast level, grind level, and brewing method. But the roast level is sort of a baseline for all us coffee drinkers, and they range from light to dark in color.
Before roasting, green coffee beans are soft, with a fresh “grassy” smell and little or no taste. The coffee roasting process transforms these raw beans into the distinctively aromatic, flavorful, crunchy beans that we recognize as coffee.
Light Roasts - Blonde
Light roasts are light brown in color, with a light body and no oil on the surface of the beans. Light roasts have a toasted grain taste and pronounced acidity. The origin flavors of the bean are retained to a greater extent than in darker roasted coffees. Light roasts also retain most of the caffeine from the coffee bean.
Light roasted beans generally reach an internal temperature of 180°C – 205°C (356°F – 401°F). At or around 205°C, the beans pop or crack and expand in size. This is known as the “first crack” (for the “second crack,” see below). So a light roast generally means a coffee that has not been roasted beyond the first crack.
Medium Roasts - Medium
Medium roasted coffees are medium brown in color with more body than light roasts. Like the lighter roasts, they have no oil on the bean surfaces. However, medium roasts lack the grainy taste of the light roasts, exhibiting more balanced flavor, aroma, and acidity. Caffeine is somewhat decreased, but there is more caffeine than in darker roasts.
Medium roasts reach internal temperatures between 210°C (410°F) and 220°C (428°F) — between the end of the first crack and just before the beginning of the second crack.
Medium / Dark Roasts - Full City
Medium-dark roasts have a richer, darker color with some oil beginning to show on the surface of the beans. A medium-dark roast has a heavy body in comparison with the lighter or medium roasts.
The beans are roasted to the beginning or middle of the second crack — about 225°C (437°F) or 230°C (446°F). The flavors and aromas of the roasting process become noticeable, and the taste of the coffee may be somewhat spicy.
Dark Roasts - Espresso / French
Dark roasted coffees are dark brown in color, like chocolate, or sometimes almost black. They have a sheen of oil on the surface, which is usually evident in the cup when the dark roast coffee is brewed. The coffee’s origin flavors are eclipsed by the flavors of the roasting process. The coffee will generally have a bitter and smoky or even burnt taste. The amount of caffeine is substantially decreased.
To reach the level of a dark roast, coffee beans are roasted to an internal temperature of 240°C (464°F) — about the end of the second crack — or beyond. They are seldom roasted to a temperature exceeding 250°C (482°F), at which point the body of the beans is thin and the taste is characterized by flavors of tar and charcoal.
So there you have it — a short guide to the common coffee roasts from light to dark. To summarize the differences, in addition to the color gradations:
As coffee roasts get darker, they lose the origin flavors of the beans and take on more flavor from the roasting process.
The body of the coffee gets heavier, until the second crack, where the body again thins.
Lighter roasts have more acidity than darker roasts.
Light roasted beans are dry, while darker roasts develop oil on the bean surface.
The caffeine level decreases as the roast gets darker.
Ultimately, it’s all about the taste, the flavor, the aroma. You may prefer a lighter roast in the morning (with more caffeine) and a darker one later in the day. Coffee, including the optimal roast level, is a personal preference. What’s yours?
