Oolong teas are a category of teas that undergo partial oxidation after the leaves are picked. Oxidation occurs after the tea leaf is picked as enzymes in the leaf react with oxygen in the air, resulting in changes to color, aroma and taste. Oolong teas undergo a difficult and time consuming processing method which produces their wonderfully aromatic and nuanced flavor profiles. They are made to be savored slowly "gongfu style", over the course of multiple infusions brewed in traditional vessels such as a porcelain gaiwan or smal clay teapot.
The method of processing oolong tea originated in southeastern China’s Fujian Province (mainly Anxi and the Wuyi Mountain area) in the 17th century. Today, the traditional producing regions include Fujian, Guangdong Province and Taiwan.
The best oolong teas are picked by hand during the spring and winter months. Processed to be full-bodied teas, the leaves for oolong tea are picked later than those for green tea, after the leaf has matured. First the leaves are withered on outdoor cloths or bamboo baskets for about two hours to reduce their moisture content. Then the leaves are spread on racks and stirred regularly for 12-18 hours in order to break down the cell structure and release essential oils. 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 10-30% for a “green” oolong such as Bao Zhong up to 60% for a “dark” oolong such as Wuyi Shui Xian. After the desired oxidation level is reached, the leaves are heated at high temperatures to prevent further oxidation. After heating, the leaves are rolled and shaped and then dried. The final stage may include a high temperature roasting or baking to develop woody, sweet and caramelized notes.
Green oolongs are distinguished by their more delicate, floral aromas while dark oolongs have more woody notes and are sometimes fruity and even a bit sweet.
Oolong tea brewing tips
One of the key aspects of oolong tea is that one serving can, and should, be steeped several times. It is over the course of many infusions that the rich aromas and flavors of oolong tea are revealed. While oolong teas can be brewed in a regular teapot or mug just like any tea, we recommend brewing gongfu style in order to appreciate oolong tea to the fullest. This Chinese art of brewing tea using a small teapot or gaiwan, an abundance of leaf and short steeping times has been developed over generations and is still used today.