Mankind has never stopped exploring the production technology since the discovery of tea. After long-term research and development, the manufacturing technique of Chinese tea is divided into seven primary processes.
After being picked, the fresh leaves will wither due to loss of water. This process is called withering. While withering, the loss of water causes certain chemical reactions that lay the foundation for ensuring color, aroma, taste quality of the tea.
The withering process is primarily comprised of two methods - natural withering or machine withering. The natural withering method can be accomplished by either indoor or outdoor. The machine withering is widely-adopted by tea factories that utilizes hot air to vaporize water, and this method expedites the withering process.
Removing Green / Fixing
Similar to withering, the goal of removing green is to vaporize water in fresh leaves, make leaves softer and suitable for rolling. Additionally, green-removing technique helps getting rid of grass smell, enabling tea to emit fascinating fragrance.
Sautéing and steaming are the most common green-removing techniques. Stir-frying fresh leaves will enhance tea aroma. Steaming is to cook fresh leaves with vapor. The color of tea appears greener if made by this steaming technique.
After withering, the majority of tea leaves must go through the rotating process during which withered leaves are laid on sieve. By rotating the sieve, creating dynamic friction among tea leaves, water continues to fade away, the tea leaves get oxidated gradually, result in a unique quality of color, aroma and flavor.
The degree of rotating is a qualitative art rather than a quantitative science. An experienced tea maker judges the tea condition via touching, looking and sniffing.
Just as the name implies, rolling tea leaves in a way similar to kneading dough. Rolling helps transforming the structure of tea leaves and increasing density. This procedure can be performed either manually by hands or automatically by machine.
Baking, also called drying over a fire, plays a vital role in improving the color, aroma and flavor. The primary purpose is to eliminate excessive water, thermalize the substances in tea leaves, enhancing aroma, stabilizing the quality of tea leaves for easy storage.
Baking can be done by either charcoal method or electric method. The stronger the baking fire, the more mature, darker the color; the weaker the baking fire, the less mature, lighter the color.
Please note the effects of fire in baking and green-removing are different. While the fire in green-removing procedure is intended to stop fermentation of tea leaves, the fire in baking procedure is to deliberately change the aroma and flavor.
After green-removing and rolling, tea leaves are accumulated and let the color become yellow gradually in a damp and warm environment. This procedure is called yellowing. Muggy yellowing is a unique technique in making yellow tea. Humidity and temperature are two determining factors in the yellowing progress. The higher temperature, the higher humidity, the faster the progress; the lower temperature, the lower humidity, the slower the progress.
Piling is a unique fermentation technique in making Pu'er tea. The color of tea leaves is turning darker gradually until chestnut black. This type of tea is often called the “black tea”.
The principle of piling is similar to that of muggy yellowing by utilizing humidity and heat. Normally we can judge the degree of piling via the color of tea soup. The darker the soup color, the heavier the piling; the lighter the soup color, the lighter the piling.
Different varieties of tea have different manufacturing procedures. Not all teas have to go through these seven procedures. Many of them have to go through three to five of these procedures only. The ultimate goal is to achieve "one-sniff-one-sip will have fragrance lingering in nose, lip, teeth, and have lasting aftertaste".