Roasting

Coffee roasting is an important process in determining flavor, and even the same beans can taste different depending on how they're roasted.
When roasting begins in a roaster, the beans first enter the drying stage at 100-160°, which removes the green smell of the raw beans.
The temperature then rises to around 150°, causing sugars and amino acids to combine and release an aroma. This change in state is called the Maillard reaction, and a fragrant aroma is released. The Maillard reaction brings out sweetness and aroma.

Coffee is brown or black before drinking, but this is because the green beans are roasted and then burnt.
This process of roasting the beans is called roasting, and the roasting process affects the coffee's taste.
Some coffee shops and cafes roast their own beans, while others purchase them from roasters.
Mass-production roasters are capable of roasting over 100 kg in a single roast.
Most roasters use drum-type roasters, either city gas or propane.
Drum-type roasters come in three types: (1) direct-under type, (2) hot air type, and (3) semi-hot air type.