When we mention tea, we seem to feel a green, fresh, and fragrant aroma. Tea, born between heaven and earth, makes people feel calm and peaceful. Tea leaves, from picking a single leaf to withering, sun drying, and finally turning into a fragrant aroma on the tongue, are closely related to “green”. So, how many ways can tea be processed?

1. Tea fixation
The so-called fixation refers to the destruction of the tissue of fresh leaves. The tea fixation process involves taking high-temperature measures to rapidly transform the contents of fresh leaves. As is well known, tea contains a substance called enzyme, which is a biological macromolecule with biocatalytic function. It is a biocatalyst that can accelerate or slow down the speed of biochemical reactions, but does not change the direction and products of the reaction. Enzymes are mostly composed of proteins (with a few being RNA), and their activity is easily influenced by factors such as temperature and chemical environment (such as pH value).
Enzymes undergo irreversible damage to their protein molecular structure under high temperature, resulting in complete loss of enzyme activity. The “withering” of tea leaves utilizes the high-temperature deactivation property of enzymes to timely inhibit the activity of oxidase in fresh leaves.

The main purpose of tea fixation is to use high temperature to destroy the polyphenol oxidase activity in fresh leaves in a short period of time, inhibit polyphenol enzyme catalyzed oxidation, and enable the contents to form the quality characteristics of Pu’er tea such as color, aroma, and taste under non enzymatic action. Qingqing can also remove some moisture, turning the leaves from hard to soft, making it easy to knead and shape. In addition, withering can remove the grassy scent of fresh leaves, allowing the tea leaves to emit a charming tea aroma. In short, destroying the organization and structure of fresh leaves, transforming the shape and quality of fresh leaves, and laying a good foundation for the unique quality of tea leaves are both the purpose of withering and the basic basis of withering technology measures.

2 Sunbathing

Fresh leaves that have been sun dried after fixation and rolling are collectively referred to as “sun dried green tea”. Yunnan’s unique Pu’er tea must be sun dried before it can be transformed into Pu’er tea. Sun drying, as the name suggests, refers to the drying process of raw tea that has been sun dried. Sun drying refers to the drying method of raw tea, not the withering method. The usual production process of Pu’er tea is: picking, spreading fresh, withering, cooling, rolling, and drying. Sun drying is the drying process after rolling. The important difference between sun dried tea and other drying methods such as stir frying and drying is “temperature”. The drying process of stir frying and drying has a high temperature, which basically cuts off the life of enzyme active substances in tea leaves, while sun dried tea is different. Natural sunlight and low temperature retain the growth possibility of active substances. Sun dried tea has a loose and black body shape, and dry tea has a clear sun dried taste. This sun dried taste presents a fresh aroma of natural flowers and plants, and the aroma is long-lasting and the taste is pure after brewing. Sunbathing also creates potential vitality for the long-term storage of Pu’er tea, which becomes more fragrant over time.

It should be noted that “sun drying” is not necessarily necessary. In rainy or cloudy days, drying or shade drying methods may also be considered, but it must be done at low temperatures, which is the key. It is generally believed that the temperature should not exceed 60 degrees. Although the low-temperature drying method of sun drying is longer, it retains the original flavor and active substances of the tea. Ensuring a suitable low temperature is an important difference in the production process between Pu erh tea and green tea. Green tea uses high-temperature sterilization to quickly enhance its aroma, but subsequent storage cannot achieve the “more fragrant Pu erh tea becomes” effect. It can only be consumed within a limited time, otherwise the tea soup will become weak and lose its value if stored for too long. Pu erh tea is a slow product, a product of time, which also includes the “slow work produces fine work” in the production process.

tea roasting and baking green tea

Stir-frying and baking green tea belong to the production process of green tea. The purpose of both is the same, which is to use high temperature to stop the fermentation process of tea leaves. The difference is that one is stir-frying in a high-temperature iron pan, and the other is directly baking at high temperature. Stir-frying green tea refers to the process of using a low fire to wither the tea leaves in the pot during the production of tea leaves. The water content of the tea leaves is quickly evaporated by manual rolling, which blocks the fermentation process of the tea leaves and completely retains the essence of the tea juice.

The green tea that has been withered, rolled, and then dried is called baking green tea. Baking green tea is a high-temperature drying process, and the tea leaves made are often highly fragrant. Therefore, some merchants have mixed baked green tea with Pu’er tea to enhance the aroma of the tea leaves, but it is not conducive to the later transformation of Pu’er tea, so consumers should be cautious when purchasing.
Baked green tea and stir-fried green tea cannot be used as the raw material of Pu’er tea, and should not be used to process Pu’er tea. Pu’er tea fermentation mainly relies on the auto-oxidation of sun-dried green tea itself, the enzymatic oxidation of polyphenols, and the action of microorganisms. Due to the high withering temperature of roasted and fried green raw tea, polyphenol oxidase is passivated and destroyed. In addition, high temperature and rapid drying are used when drying the raw tea, which further destroys polyphenol oxidase. In addition, the water content of roasted and fried green raw tea is low, and “natural aging” cannot be completed. Therefore, it is not suitable to be processed into Pu’er tea.

Steamed green/highly popular ‘matcha’

Steaming green tea also belongs to the production process of green tea. Steaming green tea is the earliest tea invented in ancient China. It uses steam to soften fresh tea leaves, then rolls and dries them. Steamed green tea often has the three green characteristics of “color green, soup green, and leaf green”, which are beautiful and tempting. Steamed green tea is a major commodity of Japanese green tea, and the tea used in Japanese tea ceremony is the globally popular “matcha” in steamed green tea.