Oolong tea, sometimes called wulong, is a traditional Chinese tea that falls somewhere between green and black teas in that they are only partially oxidized. Oolong comes in a wide range of aromas and tastes, and is often divided by those that are more “green” (10 to 45 percent oxidation) and those that are more “black” (up to 70 percent oxidation).
Tea leaves picked for Oolong teas are more mature than those used for green tea, as often up to three leaves are picked along with the bud. The tea is immediately put out to wither for about two hours as is done with green teas, but then it is left to oxidize for 12-18 hours longer. During this time, the leaves are kept slightly heated and are stirred regularly, which releases the aromatic oils and breaks down the cell structure while allowing oxidation to take place. Next the leaves are heated to stop the oxidation process, and are rolled and dried similarly to green teas. Lastly, the leaves are often (but not always) fired at a high temperature. This final firing can add woody, sweet, even caramelized aromas to the finished tea while reducing astringency and caffeine in the liquid brew. You may be familiar with Oolong teas from your favorite Chinese restaurant, as it is the tea of choice to be served with meals. Oolongs are said to aid digestion and are recommended to help increase metabolism.