Unroasted coffee beans start out a green color. The art of roasting the green coffee beans changes them to any of the roast types seen above and described below.
Each roast type have qualities about it that is different than the others. Each roast type changes what is happening on both the inside and outside of the bean as the temperature increases and roasting continues.
The different compounds of the beans start to caramelize and blend together as the roasting process continues towards its final roast type as the cooling begins.
This type of coffee roast is light brown in color as it is generally preferred for milder varieties of coffee. This roast type is not roasted long enough for the oils inside the coffee beans to break the surface.
Light roasts are typically called: Light City, Half City, or Cinnamon.
This coffee roast is a medium brown color with a stronger flavor and a non-oily surface.
This is generally the preferred coffee roast in the United States and is often called an American Roast, Breakfast, or City roast.
Medium Dark Roast
This coffee roast has a rich darker color with some oil on the surface. This roast will give an aftertaste that is slightly bittersweet.
This roast is often called a Full City roast.
This coffee roast results with an oily shiny black beans after the roasting process. It exhibits bitterness with reduced acidity the darker it is roasted. Dark roasted coffee range from slightly dark to charred.
The dark roast goes by many names that can be swapped: Viennese, Espresso, European, New Orleans, High, Continental, Italian, and French.