All the potential flavor of a coffee bean is locked in the green (raw) bean. Roasting releases the oils and acids that give each variety of bean its unique flavor. Once these oils and acids are released from the inside of the raw bean, they are vulnerable to flavor loss. To get the richest flavor into a coffee cup, it is important to start with the freshest beans possible.

The type and amount of acidity in a coffee bean varies, depending on the variety and the way they were roasted. Acid in coffee does not mean sour, but provides a sparkle and complexity that is due to the chemistry of bean varieties. It makes the coffee interesting and lively. The darker the roast the more body the coffee has, but it is gained at the expense of losing the subtler acid overtones. Roasting is an art. A roaster will vary the darkness of a roast according to the coffee bean variety, aiming at a very definite balance between acid and body.

The flavor of coffee is described with such terms as earthy, grassy, winey, spicy, and fruity, just to name a few. The flavor can be described as clear or sharp. Flavor is the attribute that most separates bean varieties. Trying different varieties will educate your palate to the fine differences, and help you decide which one you like the best. Don't give up on just one try. Sometimes a different roaster may bring out the beans' flavor in a way that is more appealing to you.

The darker roasts like Vienna, French, Italian, and Espresso roast are different because the oil of the bean comes to the surface. The body and flavor of these beans will come through if you like to add a lot of cream to your coffee. The darker the beans, the more caramelized they become. The darkest, the Espresso roast, is very low in acid and has lost the subtle flavor that distinguishes one bean from the next, but is very heavy bodied. This is a necessity when brewing with the high concentration of an espresso machine.