If you are a coffee drinker, you know the different roasts – light, medium, medium-dark and dark roast. The roasting of coffee beans is one of the most important determinants of their taste.

In their natural state, coffee beans are green and soft. When beans are roasted, the temperature of the bean increases, causing a chemical reaction to occur, creating the lighter-in-weight, darker colored bean we are familiar with. The sooner you brew the coffee after roasting, the better the fresh roasted flavor.

Other elements also enter into the mix that gives you a coffee’s flavor – where the coffee is grown, its age, how it’s processed, the grind, and how it is brewed all matter. But for a general guide as to what you can expect to taste, the roast is it.

Beans that are light roasted are a light brown color and give you a milder flavor of coffee. They also have more acidity. The taste is also more fruity and the aroma stronger. Light roasted beans have more of the original flavor of the bean and more caffeine as well. They are roasted until reaching a temperature between 350 and 400 degrees Fahrenheit, just before the beans begin to crack and expand, an event called the first crack.

Medium roasts have beans that are a little darker than light roasted. Medium roast is the most popular among coffee drinkers. The medium roast yields a more bittersweet taste and a deeper flavor. It also has less caffeine than the light roast. For a medium roast, the beans are heated from 410 to 430 degrees Fahrenheit.

Medium-dark roasts have a heavier body than the lighter roasts. These beans are heated to temperatures between 440 and 450 degrees Fahrenheit. With this roast, you can begin to actually taste the flavors released from the roasting process itself.

Dark roast coffees are almost black in color, and much of the oil locked in the beans is released. The original flavors of the bean have been eclipsed by the flavor produced in the roasting process. These beans are heated to between 460 and 480 degrees. Coffee drinkers know the distinctive bitter, almost burnt taste of dark roast. This roast also has much less caffeine.

Two of the better known dark roast coffees are French roast and Italian roast. The oils in the beans deliver the distinctive roast flavor of each. The Italian roast beans are even darker than the French roast, and so have even more oils released.

Scientists have discovered that the darker roasts have more antioxidants than lighter roasts and so may be healthier. Drinking coffee in general may also reduce the risk for diabetes and Alzheimer’s.