Unless a coffee is named after its growing region it is most likely a blend of beans from different regions. Probably the most known blend (and the oldest) is a simple Mocha-Java. The blend originated when the only two coffees were Yemen Mocha, and Java, yet the blend retains its popularity because it embodies the principle of balancing extremes. Together, the fruity and winey Yemen, with the rounder, deep-toned Java make a balanced and complete cup. To create a quality blend, you need an idea of your goal cup, and a substantial amount of expertise. The blender must have an extensive knowledge of the flavors profiles of different regions and how different processes effect those flavors. As many blends are of beans at different roast degrees (to maximize roast taste complexity) a roaster must also know how those flavor profiles change through the roast. They must also continuously sample beans from their supplying farms to evaluate the change and adjust their blends accordingly. Blends generally contain up to nine different regions (after nine it gets pretty muddy and pointless) and the beans can be blended before roasting or after. Blending is a crucial step in getting that cup of coffee that we're looking for, and a rather complex and involved step as well.