Black Tea undergoes a full fermentation process composed of six basic steps: withering, rolling, sorting, fermenting, firing (or drying) and grading. Roll breaking cracks the surface of the leaf exposing the leaf's enzymes to air initiating oxidation. Oxidation is the process that results in the flavor profiles of Oolong and Black tea, which is often full-bodied and robust. Although it contains the highest amount of caffeine compared to the other tea types, it is still well below the amount found in coffee or sodas.