Difference Between Dark and Light Roast Coffee
It's not always the origin, environment, or method of processing that determines why certain coffee beans taste stronger than others (although those factors certainly do play a part). How deeply the coffee beans were roasted often determines which taste is the strongest. The first clue as to how your coffee will taste is the light and dark roasts. What, therefore, is the distinction between dark and light roasts?
Start with a mild roast. Dark roast coffee receives more heat than light roast coffee. Similar to cooking any other ingredient, heating coffee beans effectively causes the water and moisture to evaporate from the bean. As a result of not being kept on the roasting machine for as long as dark roasted beans, light roasted beans retain more moisture, which makes them denser.