Black Tea, Oolong & Pu-erh

Black tea is the most popular in America. Complete oxidation gives this type of tea its character. Black tea is first withered – both physically and chemically. Physical withering reduces moisture, which encourages oxidation. Chemical withering creates the biochemical changes needed to convert the juices inside the leaf to more complex liquoring compounds.

Two types of styles are used to process black tea – orthodox and cut-tear-curl (CTC). Orthodox teas are whole-leaf, and are of highest quality. In the orthodox method, the withered leaves are then rolled, which encourages internal enzymes and polyphenols to mix, creating an enzymic oxidation of catechins. Only internal injury to the cell structure is wanted in this process, whereas in CTC the leaf is chopped into pieces. Next, the tea leaves are broken up and sifted through. The oxidation process then ensues in oxidation rooms and the catechins in the leaf absorb a high amount of oxygen. Lastly, black tea is dried and cooled in order to stop biochemical activity.

During CTC, leaves are preconditioned through sifting and shredding. It then goes into a leaf shredder and is minced in a Rotorvane (creating Chutney). Next it is rolled through a succession of four or five rollers. CTC drum oxidation occurs, which allows for even granulation. Continuous oxidation equipment can be substituted for this process.

Black teas include: Assam, Ceylon, Darjeeling, Keemun, Nilgiri, Sikkim and Yunnan. Many popular black teas are blends, such as English Breakfast.


Oolong teas are the most difficult to manufacture. Oolong is made from large tea leaves. They are only partly fermented – and range in colour from green to black and in flavour from fruity to sweet. Initially, these tea leaves are plucked and then withered (generating heat). They are then cooled down and withered again (they wilt, flatten and stick to the tray). After, they are rattled or shaken, causing the leaf cells to rupture. The sap thus disperses throughout the leaf, starting the oxidation process. Next, they are bruised/tumbled. Lastly, they are fired and tumbled. After a final drying process, oolong tea is complete.

Oolong teas include: Formosa Oolong and Tie Guan Yin.


Pu-erh, from old Chinese, is translated to black tea and fermentation distinguishes it from other teas. The leaf may or may not be oxidized, but microbial activity always takes place creating true fermentation. Pu-erh leaves are large and richly coloured, made from oxidized (cooked) or nonoxidized (raw) leaves. They can be found in loose leaf form or compressed into round cakes (beeng cha). The best pu-erh comes from long-lived tea bushes in China from the southern Yunnan Province.

There are two types of Pu-erh tea:

1. Sheng pu-erh (raw or green)

a) Mao Cha – Young green, which needs proper storage and aging

b) Dry storage, naturally aged – The best pu-erh, it is authentic, compressed, caked or bricked

2. Shou pu-erh (cooked or black)

a) Wo Dui (wet-pile fermented) – Usually loose-leaf, ready for consumption

b) Wet storage, quickly aged – Compressed into beeng cha

Sheng pu-erh is plucked and processed through standard methodology, and is then left to air dry followed by being fired. If it is to become raw pu-erh, the leaves are fired completely. The leaf is gathered and turned regularly to create fermentation. Mao Cha is packed into a compressed form and ages for ten years, while undergoing post-fermentation.

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