80 percent of coffee flavor is determined by roasting.

Baking, as the name implies, is to provide heat to coffee beans, and to produce chemical changes in the internal structure of coffee beans by heating, that is, heating converts starch in raw beans into sugar 5 or acidic substances at high temperature. substances such as cellulose will be carbonized to varying degrees by carbon, water and carbon dioxide will be evaporated, proteins will be converted into enzymes, and the remaining substances of fat will be combined. An oil film is formed on the surface of coffee beans.

The main purpose of baking is to produce this aromatic oil, which is called coffee oil, or, more accurately, coffee oil, which gives coffee beans a strong aroma. This aromatic oil is volatile, that is, it is the main factor that brings flavor and fragrance, and they can accommodate water, which means that people can enjoy it in a cup.

Baking must be uniform, the most important thing is to be able to stir-fry the beans evenly inside and outside. At first, the water in the coffee beans should be discharged smoothly by fire. if only fast and uneven is required, it may cause the beans to have a beautiful appearance but a light internal color, and has not yet begun to decompose. The deep, medium and shallow companionship of beans during baking is decided and controlled by people, and even there is a knack for cooling beans before the end of baking. If the temperature is not cooled quickly, the heat contained in beans will make the beans darker and greasy, and the taste will become bitter.

Baked coffee beans swell, a bit like popcorn, and crackle during baking, just as we make popcorn in a microwave oven. But because the skin on the surface of coffee beans is very tough, we usually don't see coffee beans crack like popcorn.

The color of roasted coffee beans changes from light green to tea brown, which can not only change the unique color of amber, flavor and aroma, but also volatilize the sour, sweet, bitter, mellow and fragrant five obvious taste characteristics of coffee. If the baking technology is good, the beans will be large and expanded, no wrinkles on the surface, uniform luster and each has its own different flavor.