Kill Green in Tea Production

Have you ever wondered why Japanese green teas are so bright green, while Taiwanese and Chinese ones are not. The reason lies in an additional process called de-enzyming, fixation or “green killing” and comes from Mandarin shaqing (杀青). This process allows to stop the fermentation (oxidative browning) at the required level by denaturing the enzymes responsible for oxidation – polyphenol oxidase and peroxidase.

Imagine an apple - if you cut it, then the cut will darken quickly enough. However, in apple pie, the color of the apples remains light. This is because heat prevents enzymatic browning. The same is with tea.

“Kill green” is produced by moderate heating of the leaves, which deactivates oxidizing enzymes, removes unwanted odors, leaving the aroma of tea intact. Traditionally, the leaves are fried in a deep wok, heated in a basket, or steamed for fixation. Also, sometimes drying is done in a rotating barrel. For some white and some black teas, this operation is carried out simultaneously with drying, as a second heating cycle. Due to the rapid heating in the tea leaf, oxidation, fermentation and wilting of the juice stop, which gives the tea a richer taste and bright green color of the leaves, as well as the tea drink.

We would like to present you Peach Flavor White Tea Oolong from Li Shan Hwa Guan / Hua Guan which is done using this technology.