Oolong teas are neither green nor black, but everything in between. They are made from tea leaves that are only partially oxidized.

Because oxidation can be stopped at any point, oolongs can provide a wide array of flavors and provide the most complexity in taste, often becoming the most favorite type of tea for most tea connoisseurs. They are also the most labor intensive, time-consuming, and complicated teas to produce.

The degree of oxidation in the oolong leaf is controlled by the amount of time the raw leaf is allowed to be exposed to oxygen, or its withering time, in addition to the amount of rolling or bruising it undergoes. Rolling or tossing the leaves not only serves to accelerate oxidation, but also to bring forth the tea’s essential oils to the leaf surface.

Each oolong producing region will have its own style of rolling, clustering or twisting, and roasting the leaves, with in combination with the leaf varietal used, will amount to different flavors and aromas. While some oolongs will remain very green in character, and others will be heavier in profile like a black tea, all oolongs will exhibit a degree of reddish coloring on the edges of its leaves, depending on the amount of oxidation.

To stop the oxidation process for oolong teas, the leaves are fired in pans or ovens with rotating drums. Tea craftsman then roast the leaves to remove excess moisture and add additional character to the tea. Sometimes the roasting is performed by placing the withered tea leaves on racks in a convection oven, or done traditional style on racks over charcoals using specific types of wood as fuel.

The amount of roasting and number of roasts the oolong undergoes can entirely alter the oolong’s flavor and aroma profile and vary from region to region and particular tea maker. From plucking to the final roast, most well-crafted oolongs will have undergone upwards of two days worth of alternating stages of withering, rolling and roasting to create the final product.

Types of Oolong Tea

Oolongs are typically named after their varietal or mountain they are from. These are the four traditional oolong producing regions:

Wuyi

Wuyi Mountain of northwestern Fujian province, where oolongs first originated, produces rich, dark, heavily oxidized and roasted oolongs with twisted leaves. These oolongs are often called “yan cha” or “rock tea” –a reference to both the rocky cliff sides on which they grow and the mineral quality that arises in the tea’s finish as a result of this special terroir.

Anxi

Anxi County, along the southeastern side of Fujian, is renowned for the complex Tikaunyin, or Iron Goddess of Mercy, varietal of oolong. The traditional style of crafting Tikuanyin results in a more medium bodied oolong, with a balance in flavor between its floral, fruit and toasted and nutty notes.

Formosa

Across the straits from Fujian province, Taiwan is the youngest oolong manufacturing region and grows the tea throughout the island. Its style of crafting oolong is to oxidize the tea very lightly with very minimal roasting, thereby retaining the green and floral character of the tea. Northern Taiwan is known for Wenshan Baozhong, a large leaf twisted oolong that is sweet, floral and delicate, while central and southern Taiwan produces High Mountain oolongs, so named for the illustrious heights at which these oolongs are grown, providing a terroir that yields an unrivaled mouth feel and finish to the tea liquor.

Phoenix

Phoenix Mountain of the southeastern region of Guangdong province produces a type of oolong that has been popular since the 10th century. These oolongs are unusually harvested from single groves, as each of the Phoenix varietals emulate specific fruit or flower fragrances and/or have a specific heritage that must be preserved.