The best oolong tea is picked by hand during the spring and winter months in southeast China and Taiwan. Oolong teas are partially oxidized teas and undergo the most difficult and time consuming processing method. Processed to be full-bodied teas, the leaves for oolong tea must not be picked too early but just when they reach their peak, and they must be processed immediately. First the leaves are withered in direct sunlight and then shaken gently in bamboo baskets to lightly bruise the edges of the leaves. Next the leaves are air-dried in the shade until the surface of the leaf turns slightly yellow. The process of shaking and drying the leaves is repeated several times. The oxidation period for oolong teas is less than that for black teas and depends on the type of oolong. This can vary from about 20% for a green oolong to 60% for a classic Formosa oolong. After the desired oxidation level is reached, the leaves are panfired at high temperatures to prevent further oxidation. Due to the higher firing temperatures, oolong teas contain less moisture and have a longer shelf life than green teas.
