Roasting is a heat process that turns coffee into the fragrant, dark brown beans we love. Before being roasted, the beans are stored green, so they can be kept without loss of quality or taste. Once roasted, however, they should be used as quickly as possible.
Roasting is a technical skill which approaches an art form. It takes years of training to become an expert roaster with the ability to 'read' the beans and make decisions with split second timing. The difference between perfectly roasted coffee and a ruined batch can be a matter of seconds.
Roasting brings out the aroma and flavor that is locked inside the green coffee beans. A green bean is soft and spongy to the bite and smells green, almost 'grassy.' Roasting causes chemical changes to take place as the beans are rapidly brought to very high temperatures. When they reach the peak of perfection, they are quickly cooled to stop the process. Roasted beans smell like coffee. Roasted coffee weighs 20% less than its original green form because the moisture has been roasted out. Roasted beans are crunchy to the bite, ready to be ground and brewed.
Most roasters have specialized names for their favored roasts and there is very little industry standardization. In general, roasts fall into one of four color categories—light, medium, medium-dark or dark.
Within the four color categories, you are likely to find common roasts as listed below. There can be a world of difference between roasts!
Light brown in color. This roast is generally preferred for milder coffee varieties. There will be no oil on the surface of these beans, because they are not roasted long enough for the oils to break through to the surface
- Light City
- Half City
Medium brown in color with a stronger flavor, and a non-oily surface. This roast is often referred to as the American roast because it is generally preferred in the United States.
Rich, dark color with some oil on the surface and with a slight bittersweet aftertaste
- Full City
Shiny black beans with a oily surface and a pronounced bitterness. The darker the roast, the less acidity will be found in the coffee beverage. Dark roast coffees run from slightly dark to charred.
- New Orleans