Just smelling coffee can help wake you up! A group of scientist reported that simply smelling the wonderful aroma of coffee can alter the activity of some genes in the brain, thus reducing the effects of sleep deprivation! And when you do end up drinking that cup of coffee, the caffeine reaches your blood stream fast...like around 10 minutes fast! And speaking of caffeine, dark roast coffees have less caffeine than lighter roasts. Even though the flavor is often strong and more robust, roasting actually burns off some of the caffeine!