Roasting is the heat treatment which transforms the green beans into the aromatic brown nuggets that we buy whole or ground.

Most roasters use air temperatures of about 550 degrees Fahrenheit. The beans are kept moving during the roasting process to keep them from burning. When the beans reach a temperature of about 400 degrees Fahrenheit, they start to turn a darker brown, and the oils (called coffee essence, coffee oil or caffeol) start to emerge. This process, called pyrolosis, is at the heart of roasting, as it produces the flavor and aroma of the coffee we drink.

When the beans are removed from the roaster, they are cooled by air or water. Roasting is performed in the individual importing countries, because roasted beans must reach the consumer quickly to get the full coffee flavor.