Oolong Tea

Photo 1: Oolong Leaves & Tea
Photo 2: Oolong Varieties

Blue-Green or Oolong "Black Dragon" Tea: A Semi-Oxidized Tea

This tea family is halfway between a green tea and a red tea. As the degree of oxidation of the leaf is the determining factor, teas with very different aromas are produced. This is one of the most varied families and one of the richest in aromatic diversity.
The teas are known as Oolong ( wu long) or blue-green (qin cha). The latter term is used mainly by producers and traders within the industry.
The first stage of processing is withering, as with red tea. The young, freshly picked shoots are spread out in the sun on bamboo mats for about an hour.

The second stage combines two of the stages used in red-tea manufacturing: rolling/heating and oxidation, which are carried out alternately until the desired level of semi-oxidation is achieved.
This phase takes place in a room shaded from the light and in a warm atmosphere in order to accelerate the oxidation process. It is at this stage that the leaves are shaped- into pearls, twists, and so on. The duration of this stage depends on the type of wu long required.
Four major families are produced according to the degree of semi-oxidation: semi-oxidized wu long teas at between 5- 15% (5-15% of the surface of the leaf is oxidized); 2- 30%; 30- 40%; and 60 - 70%.
Many wu-long teas are then roasted to bring out the aromas of the leaf and to develop pyrogenic, toasted notes. This tradition is mainly popular among the Chinese.
The finest Oolong teas come from mainland China (Fujian and Guangdong provinces) and from Taiwan, which has specialized in and perfected the production of this type of tea.

-p. 103, Alchemy of Tea in Tea: Aromas and Flavors Around the World by Lydia Gautier (2005)

Oolong Varieties
Wu-Long Oolong Tea