There are few things that you notice more about a bag of coffee than the roast profile. Behind that consistently perfect light, medium and dark roast is all sorts of complex chemical reactions impacting everything from acidity and sweetness to body and aromatics. Coffee is roasted at 180230 o C for 815 minutes. The first crack is the start of drinkable coffee, with the second crack representing the start of dark roast. Anything roasted past the first crack produces a light roast, retaining native characteristics with bright acidity and higher caffeine levels. Medium roasts are roasted between the cracks, balancing caramel sweetness with roast experience. Dark roasts are roasted past second crack, resulting in dark chocolate, smoke notes and full body. Dark roasts don't have higher caffeine levels, despite folklore!