Heat-based kill-green, steam-based kill-green, pan-firing, oven-drying, and sun-drying are five methods of kill-green and drying used in the production of green Tea, which form the basis of its quality. Kill-green is mainly divided into heat-based and steam-based methods, followed by drying processes that include pan-firing, oven-drying, and sun-drying.

The process of making Green Tea can be summarized as plucking, kill-green, rolling, and drying. Among these steps, kill-green refers to using high temperatures to quickly deactivate enzymes in the tea leaves, preventing the enzymatic oxidation of polyphenols, and allowing the fresh leaves to lose some of their moisture, making them easier to process further. The kill-green process also forms the foundation of green tea's quality.

In general, kill-green has three main effects:

1. Deactivating enzyme activity to prevent the oxidation of polyphenols;

2. Eliminating the grassy smell and enhancing the aroma of the tea;

3. Softening the tea leaves for easier processing.

High-temperature kill-green causes the evaporation of water in the fresh leaves. After partial dehydration, the leaves become softer and more pliable, making them easier to roll into shape during subsequent processing.

The enzyme-deactivation process can be carried out in two ways: heat-based or steam-based. The drying process after kill-green can be divided into pan-firing, oven-drying, and sun-drying. Therefore, based on different kill-green methods and drying techniques, green teas can be classified into four major categories: pan-fired green tea, oven-dried green tea, sun-dried green tea, and steamed green tea.

1. Pan-fired Green Tea: This refers to a style of green tea where pan-firing (or full pan-firing) is the primary drying method, resulting in a rich, highly refreshing aroma and a mellow, refreshing taste. Dragon Well is the most famous example of pan-fired green tea.

2. Oven-dried Green Tea: This refers to a style of green tea where oven-drying is the primary (or sole) drying method, producing a fresh, clear aroma and a sweet, light taste. Oven-dried green teas do not have as strong an aroma as pan-fired green teas. Typical examples of oven-dried green teas include Huangshan Maofeng, Liu'an Guapian, and Taiping houkui.

3. Sun-dried Green Tea: This refers to a style of green tea where sun-drying is the primary (or sole) drying method, producing a tea with a high aroma, strong taste, and a characteristic sun-dried flavor. Yunnan large-leaf variety teas are of the highest quality among sun-dried green teas and are known as “Yunnan Green” or “Dian Qing.”

4. Steamed Green Tea: Steam-based kill-green is an ancient Chinese method that uses steam to deactivate the enzymes in fresh leaves, resulting in a “three-green” quality characterized by dark green dry tea, green tea liquor, and bright green leaves, with a high aroma and refreshing taste. Enshi Yulu, produced in the southeastern part of Hubei Province, is a typical example of steamed green tea.