The quality of a coffee , dear reader, is influenced by several factors, such as variety, origin, harvesting, drying, and, of course, roasting. The latter is the process by which coffee goes from its natural state (green or raw coffee) to achieving its distinctive brown color.

As the roaster's temperature increases, the coffee's color changes gradually. At 100 degrees, the beans begin to brown. At 180 degrees, they release intense aromas and acquire a caramel color. At 215 degrees, they achieve a brown color. The beans must be cooled abruptly to lock in the aromas and prevent the loss of oils. It's important to keep in mind that temperature isn't the only factor influencing the final result; the time of exposure to heat is also very important. The longer the coffee is in the roaster, the less caffeine the final product will contain.

Roasting is essential for developing coffee's aroma and flavor. Several factors influence the flavor profile of any coffee, and roasting is one of the most important.

The location, environment, climate, and altitude at which the plant is grown play a very important role. The type of washing or processing also plays a necessary role in determining the final flavor of the coffee. However, one of the greatest influences on the aroma and flavor of coffee is roasting, specifically the degree of roasting.

It's through roasting that coffee is transformed, offering us the aromas and flavors that lead us to speak highly of it. The type of roasting you apply to your coffee will enhance some qualities and reduce the presence of others.

The taste of coffee

The flavor of coffee lies in its beans. Depending on how the coffee is roasted, some aspects will be enhanced and others diminished. The final flavor profile depends primarily on the flavor-giving compounds found in the coffee beans: caffeine, which gives bitterness; acids, which create sour and sweet flavors; lipids or fats, which contribute viscosity or stickiness; sugars, which provide sweetness; and carbohydrates, which influence bitter notes and viscosity.

Toasting models

Because coffee beans vary, color isn't a very accurate way to judge a coffee roast, but combined with the typical roasting temperature that produces a particular brown color, it's a very practical way to categorize roast levels. Coffee begins roasting as green coffee, then gradually transitions to yellow and various shades of brown from lightest to darkest.

Classification of roasting in coffee

Coffee can be divided into four color ranges: light roast coffee, medium roast coffee, medium-dark roast coffee, and dark roast coffee.

1. Light roast coffee: Characterized by a more pronounced and intense acidity combined with a clear, smooth cup. Light roasted beans typically reach an internal temperature of 180 to 205 degrees Celsius. Around 205 degrees Celsius, the beans burst or crack and expand in size. This is known as "first crack," defined as the moment when the coffee beans approach a stage where they can be consumed. Light roasts do not go beyond this first crack. The roasting process does not reach the point where the bean's sugars caramelize, as this preserves the original flavor.
2. Medium roast coffee: Characterized by a medium brown color with more body than light roasts. A good medium roast can provide greater aroma intensity and sweetness without affecting the acidity. Other flavor compounds appear more balanced than in light roasts because the perceived texture in the mouth is increased, and the roast notes are not yet very evident. Medium roasts reach internal temperatures between 210 and 220 degrees Celsius, between the end of the first crack and just before the second crack. Caffeine is slightly reduced but retains more of it than in dark roasts.
3. Medium-dark roast coffee: This coffee has a richer, darker color with some oil beginning to show on the surface of the beans. Flavors and aromas become more noticeable, and with increased roasting, the intensity of the acidity decreases, the roast notes become more evident, and the body becomes heavier. The coffee beans are roasted until the beginning or middle of second crack. As the coffee is subjected to higher temperatures, it caramelizes during roasting. It generally has more bitter notes than with medium roasts.
4. Dark roast coffee: Produces shiny beans with the oil that comes from them. They are distinguished by a very dark brown color, sometimes almost black. At this stage, there are virtually no traces of acidity and they often have a slightly bitter taste. They have an oily sheen on the surface, the coffee's mouthfeel increases, and the bitter notes of caramelization appear, further covering the original flavor profile. To achieve a dark roast, the coffee beans are roasted to an internal temperature of 240 degrees Celsius after the second crack.

Finally, dear reader, you should know that roasted coffee , or its final brown color, is a very useful indicator of a specific flavor profile. Color is also a valuable indicator of how the coffee roasting is progressing. And in addition to color, the way the roaster is handled has a telling effect on the final flavor profile of the coffee during the roasting process.