Each type of coffee bean has the ideal roasting time depending on its characteristics. In fact, expert coffee roasters have to perfect specific roasting times to bring out the best flavors in each type of gourmet coffee bean. The longer the coffee bean is roasted, the more of the individual coffee flavors and undertones are burnt away. In order to make sure you aren’t missing out on flavor with your dark roast coffee preference, make sure you buy your coffee beans from an experienced roaster. Sumatra Black Satin Roast coffee is well suited for dark roast – the oily sheen on the dark chocolate beans provide optimal flavor when freshly ground and brewed. The main difference between light roast and dark roast gourmet coffee beans is the length of time they are roasted. As the roasting time increases, the coffee beans change from their original earthy flavor into a smoky or burnt taste. They also change from being very dry to becoming very oily and shiny. Acidity Dark roast coffee beans have lower acidity levels than light roast. The differing acidity levels change the taste of the coffee. A lightly roasted coffee will have a lively, bright taste while a dark roasted coffee will have a flatter taste. Caffeine There is some controversy about differing levels of caffeine in dark roast coffees. Some seem to say that dark roasted coffees have less caffeine. However, it depends how you measure the coffee beans. If measured by weight, caffeine levels are higher because water loss is faster than caffeine loss during the roasting process. If measured by volume, caffeine levels are lower because the beans expand as they roast. Either way, the difference is relatively small. Flavors Dark roast coffee beans typically have a burnt or smoky flavor; some may also classify it as strong or spicy. Often dark roast coffees will have a bittersweet taste and charcoal undertones. Body Dark roast coffee beans have are heavier-bodied. This means that the fresh brewed coffee is able to retain more flavors when cream or milk is added. The difference in body between light roast and dark roast coffee beans is similar to the difference in water and whole milk; dark roast coffee is much heavier. Antioxidants Studies from the University of British Columbia find that roasting coffee beans further improves the antioxidant content. Researchers suggest dark roasted coffee beans offer the highest antioxidant levels over all other coffee varieties as the roasting process releases the antioxidant content. Variations of Dark Roast Coffee Beans: Italian Roast, Full City Roast, Spanish Roast, Dark French Roast.