Roasting process

There are various names for the roasting process, but usually everything falls into one of the following four categories:

Light Roast
The light roaster has a mild toasted grain taste with a thin texture, strong acidity, and no oil on the surface of the coffee beans. The lightest roaster is called Light Cinnamon. This process is a light roasting process where the coffee beans will give rise to the taste of lightly roasted grains and a thin texture, high acidity, and without oil on the surface of the coffee beans. The lightest roasting is referred to as Light Cinnamon.

Medium Roast
Medium roasting will make coffee more textured and produce lower acidity compared to light roasts. Generally also known as the American Roast nickname.

Full Roast
These coffee beans will be dark in color, in solid form, and with an aromatic aroma. Full roast is divided into: Full City Roast which is strong and Viennese Roast which is dark brown and slightly oily.

Dark Roast
This roasting process is at a high level, resulting in a sharp taste and sweet smoke that can also taste bitter. The grill is divided into French Roast which is almost black and Italian Roast which is black, caramelized and oily.

Source : https://www.nescafe.com/id/perjalanan-kopi#video-teaser-one-DariBijiHinggaDiseduh

Note :
Green and raw seeds need to be roasted (roasting) before they can be brewed. During the roasting process, coffee beans develop and change color. The color turns yellow because it absorbs heat, turns brown due to loss of water content, and is darker after removing the oil. The longer it is roasted, the coffee beans will darken the color and the stronger the taste produced.

Photo by https://ictcoffee.com/