Excerpt from nca.org
Know your roasts
Most roasters have specialized names for their favored roasts and there is very little industry standardization. This can cause some confusion when you’re buying, but in general, roasts fall into one of four color categories — light, medium, medium-dark and dark.
Many consumers assume that the strong, rich flavor of darker roasts indicates a higher level of caffeine, but the truth is that light roasts actually have a slightly higher concentration.
The perfect roast is a personal choice that is sometimes influenced by national preference or geographic location. Within the four color categories, you are likely to find common roasts as listed below. It’s a good idea to ask before you buy. 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
This roast is medium brown in color with a stronger flavor and a non-oily surface. It’s often referred to as the American roast because it is generally preferred in the United States.
Medium dark roasts
Rich, dark color, this roast has some oil on the surface and with a slight bittersweet aftertaste.
This roast produces shiny black beans with an 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, and the names are often used interchangeably — be sure to check your beans before you buy them!
- New Orleans