When compared to each other, coffee beans have the same amount of caffeine. During roasting, beans lose water (i.e. mass). The darker the roast, beans will lose more mass. The caffeine levels in light and dark roasts will vary depending on how the coffee is measured. Medium roasts are lighter and more acidic, while light roasts are brighter and more vibrant.

Medium roast coffee beans can be roasted at 400 to 350 degrees Fahrenheit. Dark roast coffee beans can be pushed to 430 to 450 degrees. Coffee beans are heated to remove moisture. Dark roast coffee beans tends to be puffy and light, while lighter roasts are dense, moist, and dry. Roasting adds natural oils to the beans' surface, which is why darker roasts have a shiny appearance.

One cup (or 237 mL) of espresso contains approximately 100 mg of caffeine. Although it is unlikely to affect the amount of caffeine, there are several factors that can influence the amount. These include the type of coffee, the beans used, and the method of brewing.

Most Americans prefer medium roast coffees. Medium roast beans taste slightly sweeter than lighter roasts, and have a more balanced flavor profile and acidity. Medium roast beans have a balanced flavor, aroma and acidity that is comparable to light and dark roasts. Medium Roasts can be left to roast for a longer time to be classified as Medium-Dark. This roast is richer and darker, with oils starting the surface of the beans. This roasting process preserves the unique flavor of coffee and provides a great balance of acidity and body.

Sometimes, dark roast coffee may hint at chocolate or toasted pine. This coffee has a darker color than dark chocolate, and an oily finish. These coffee beans roast at higher temperatures and are usually left for longer. These beans will lose more moisture and become less dense. They will also have a bitter/smoky flavor. As well as Arabica beans and light roasts, dark roasts generally have lower acidity levels than their medium or light counterparts. Dark roasts are best if you want to control your acid intake and brew full-bodied brews.

Light Roast Coffee is lighter in color and has no oil. Light roast coffee has brighter and more fruity taste notes. This coffee roast retains the most of its original coffee flavor, has the highest acidity and retains the most caffeine from the coffee beans. This flavor profile is often preferred by coffee lovers and is called "bright".

Light roasts are best for drip and pour-over coffees. Dark roasts work well for espresso drinks and those with milk and cream. Both dark and light roast coffees have antioxidants and phytochemicals. However, dark roasts may be more nutritious because they lose more plant chemicals during roasting. Some studies have shown that dark roast coffees have lower levels of acrylamide, a chemical that can form in foods heated to extreme temperatures. Acrylamide has been associated with an increased risk for cancer.

Try experimenting with different types of coffee and different brewing methods if you are still not sure if light or dark roast coffee is right for you. You might also consider French press, cold brew and pour-over.