Black teas are fully oxidized after the leaves are picked. After the harvest, leaves destined for black tea are withered by having air blown over and around them. The leaves are rolled or cut. This process used to be done completely by hand, but modern machinery has taken over much of this process due to high global demands. The next step is oxidation, which is sometimes erroneously referred to as “fermenting,” though no fermentation is taking place. As the leaves oxidize, enzymes are released that change the color and flavor of the leaves. Black teas take on a reddish to brownish hue when brewed. They are characterized by a range of flavors, including roasted, tannic, smooth, or biting.