Coffee contains a lot of chemical and aromatic compounds, and when coffee is roasted, some of the properties of these compounds are changed, which results in a change in the taste and aroma of the coffee. That’s why it is better to use the best quality coffee until it is roasted professionally and with deliberate steps and proportions to ensure obtaining the best aroma and the best taste and extraction of coffee. In this article we are going to present to you the most important stages of roasting specialty coffee (coffee roast).
Green coffee beans
After the stage of picking, drying and several stages of treatment and good storage by the coffee farmers comes the roasting process while the grains are still green. The density and moisture content of the green coffee beans are usually measured by the roaster. According to the International Coffee Organization, the grains must contain: Moisture ratio between 8 to 12%. Good levels of moisture content allow the appearance of a balanced acidity and aromatic smell of the coffee, which makes the coffee roasting degrees better, as a result the specialty coffee drink better.
What happens while roasting?
When roasting coffee, chemicals interact. The goal of roasting is to improve the soluble chemical flavors in coffee, which is the main component of coffee flavors. During roasting, the color changes from green to yellow to brown to black to varying degrees, and the size of coffee beans almost increases, developing more than 800 aromatic compounds, the density of the grains decreases and it makes loud popping sounds due to the release of compressed gas and steam.
Hot Air Roasting
Coffee beans are roasted with hot air. In this method, coffee beans are roasted on a rotating machine that pumps hot air, and unlike the traditional method that is roasted in a hot steel cylinder, coffee beans are roasted with air, which is a faster, cleaner and easier method and the roasting temperature is controlled. It is also effective when repeating the process of coffee roasting in large quantities, and because air-roasted coffee tastes softer and less bitter than roasted coffee by traditional methods.
Types of specialty coffee roasting grades
The method of roasting of coffee in different grades can be divided into four degrees: light roasting, medium roasting, medium dark roasting and dark roasting. Each degree has a different taste and smell and the methods of roasting it vary from one roast to another depending on the type of coffee and its chemical components and the method of roasting the grades of coffee beans and all these grades can be controlled.
The light coffee roasting degree:
This degree of light roasting is the first degree of initial roasting process in which the coffee beans are characterized by a light brown color, they are also dry and rather hard, they are lighter in color and this is due to the fact that they were roasted for a short time, and are often roasted with more careful care than their dark counterparts with heat. It is worth noting that there is no oil on the surface of the grains; because the time spent in roasting is short, this type is used to prepare drinks with high acidity and light texture like Arabic coffee.
The Medium coffee roasting degree:
The mid-grade is very popular in most of fine specialty coffee preparation process, due to the ease of reaching this degree, the air temperature is raised and the beans will begin to develop flavors while not sacrificing too much pleasant acidity or intrinsic flavors, as they are likely to have a sweet flavor, and be less dense than lightly roasted beans, which is the best of all coffee roasting degrees.
Medium dark coffee roasting degree:
At this stage coffee beans are roasted several minutes longer than the average roasting, and that way you reach this degree of roasting, and you will find a difference in the color of the beans with a very clear flavor. This type of coffee is most often characterized by heavy texture, and the flavor may be strong, combining the sweet and bitter taste, while the taste of acidity is less than light roasting or medium roasting and the beans are slightly shiny as the oils begin to rise to the surface of the coffee beans, which take on a dark brown colour in addition to a fairly soft texture.
Dark coffee roasting degree:
Coffee is roasted a little longer compared to previous roasting degrees, and the grade of these beans must be roasted long enough until the oils come out of them, resulting in dark roasted coffee beans shiny brown in color. Due to the length of the roasting period, coffee beans may lose all the original flavors due to the high temperature, but this create new flavors, and it result in coffee beans losing more moisture, making them less dense and less caffeinated, which is the worst degree of coffee roasting.
The degrees of roasting of coffee is the main factor in determining the extent to which you taste the intrinsic flavors, as well as its being a key factor in the overall balance of flavors resulting from roasting coffee grades.