To be able to produce coffee, it starts with green coffee beans, soft spongy beans that smell like grass, which are thoroughly dried and later roasted and brewed to come up with an aromatic, flavorful drink.
When roasting the green coffee beans, the gradual building up of heat helps in causing chemical changes to take place in the beans, such that when the desired temperature is reached, the beans are in a roasted appearance and a roasted aroma is emitted which is uniquely characteristic of coffee. Green coffee beans contain levels of amino acids, protein, sugars and caffeine, a stimulant which is linked with the central nervous system, but as soon as they are roasted, a Maillard reaction takes place, which is a chemical reaction between amino acids and sugars take place, and the effect is brown, roasted beans that possess a distinct aroma and flavor.
The art of roasting coffee is an accumulation of years of training, expertly reading when the beans are on the roasted temperature and time, which can make a difference between good aroma and flavor and a burnt flavor. The best coffee roasters know when is the right roasting time to achieve the kind of coffee that can come out and, basically, there are four categories – light, medium, medium-dark, and dark. All categories give that aromatic smell but the flavor of each differs.
Sound is a good indicator of the roasting temperature, such that there are two temperatures to watch during roasting, which produce a distinct sound in each, – temperature at 196 degrees Centigrade which emits the first crack sound, marking the beginning of a light roast coffee, and at 224 degrees Centigrade, which emits the second crack.
Light roasts coffee are light brown in color and characteristic of having no presence of oil on the surface because they have not been roasted long enough for the oils to come out. Common examples in the market of light roast coffee are known as Light City, Half City, and Cinnamon Coffee.
Medium roast coffee is of medium brown, has a stronger flavor than light roast coffee and, still, non-oily. City Coffee, American Coffee, and Breakfast Coffee are examples of names which refer to medium roast coffee.
The characteristics of medium dark roast coffee are rich, dark color, slightly oily, and having a bittersweet aftertaste. Full City coffee is popularly its commercial name.
The following characteristics are found in dark roast coffee: shiny due to the oil that comes out during roasting, has a bitter taste, less acidity and slightly dark to charred color. Dark roast coffee are popularly preferred by most people, that’s why it comes in many commercial names, such as High, Continental, New Orleans, European, Espresso, Viennese, Italian, and French. Visit https://en.wikipedia.org/wiki/Coffee_roasting to learn more.