1. What is the post-fermentation of Pu-erh tea?

The post-fermentation of Pu-erh tea essentially means that the finished tea still contains spores and mycelium of fungi such as Aspergillus niger, Rhizopus, Mucor, and yeast. They rely on tea leaves as a nutrient base and can grow and reproduce under suitable temperature and humidity conditions. These fungi can germinate at temperatures above 15 degrees Celsius and air humidity above 60%. The mycelium can produce spores for asexual and sexual reproduction, and the reproduction rate is very fast, completing a generational alternation in tens of minutes or hours.

Tea friends should know: The various manifestations of Pu-erh tea's post-fermentation are the secret behind its health benefits!

In a liquid culture medium at 35 degrees Celsius, the reproduction speed of fungi is extremely fast. For fungi, Pu-erh tea leaves are a rich granary. The author once conducted microbial culture experiments on raw cakes from the 1960s from the Menghai Tea Factory. After strict disinfection, the tea leaves could grow Mucor, Rhizopus, Penicillium, and Aspergillus niger on the culture medium. On days 3-6 after inoculation, the mycelium of Mucor and Rhizopus covered the entire culture bottle like cotton balls, indicating that in the early stages of culture, these easily reproducible fungi like Rhizopus and Mucor dominate.

Pu-erh tea is a post-fermented tea. During the storage of finished Pu-erh tea, both raw Pu-erh and ripe Pu-erh can, under good conditions, improve the quality and taste of the tea through a post-ripening process that lasts for several years to several decades, giving Pu-erh tea its characteristic of relatively improving with age and certain special health functions for the human body.

2. What are the benefits of this fermentation in Pu-erh tea for us?

Pu-erh tea is a product of fermentation. Many fermented products, including Pu-erh tea, contain statin-like substances, such as Lovastatin, Simvastatin, etc., which are medicinal components for lowering blood lipids. The tea pigments in Pu-erh tea have potential blood lipid-lowering functions.

That is, by improving the deformability of red blood cells in the blood, adjusting the aggregation of red blood cells and the adhesion of platelets, reducing plasma viscosity, thereby reducing whole blood viscosity and improving microcirculation. The diuretic effects of caffeine and theophylline in Pu-erh tea have potential functions in alleviating hypertension and hyperlipidemia.

3. What are enzymes?

Regarding the four benefits mentioned above, some might ask: What is the basis for Pu-erh tea being able to take on such an important "role"? This is an "old question" and also a "new question" that always surrounds Pu-erh tea. So, the question returns to the starting point. Actually, when discussing these four functions of Pu-erh tea, we have missed one thing, which is also the biggest secret of Pu-erh tea. This secret is that Pu-erh tea is rich in "enzymes".

Enzymes are organic colloidal substances, biological catalysts produced by living cells in organisms. The vast majority of enzymes are composed of proteins (a few are RNA). All life activities such as digestion, absorption, respiration, movement, and reproduction are enzyme-catalyzed reaction processes. They are not only essential substances for maintaining normal body functions, digesting food, repairing tissues, and other life activities, but also participate in all life activities.

For example, thinking, exercising, sleeping, breathing, getting angry, crying, or secreting hormones are all results of activities centered around enzymes. Enzymes are the basis on which cells survive. The metabolism of cells includes almost all chemical reactions that are catalyzed by enzymes.

Without enzymes, our body's metabolism would not be able to proceed. The five major nutrients provided by nature to humans (carbohydrates, lipids, proteins, vitamins, minerals) would become useless to the body, and life phenomena would stop. Therefore, the importance of enzymes to life is self-evident. Many people even call them "living substances" or "substances that master all life activities".

The raw material of Pu-erh tea—large-leaf tea—contains multiple enzyme systems. The microorganisms that Pu-erh tea relies on during fermentation are also a "main force" in producing enzymes. The greatest achievement of Pu-erh tea is that all its fermentation processes occur at room temperature. This stores abundant enzymes for us. Because enzymes have a characteristic: they dislike high temperatures. Most enzymes lose activity above sixty degrees Celsius. This is why we repeatedly oppose using the "oven-drying" process for making Pu-erh tea and advocate the traditional "sun-drying" process.

Enzymatic fermentation is the most important form of fermentation during the aging process of Pu-erh tea and is also the essence of Pu-erh tea fermentation.

4. The role of enzymes

Anyone who has tasted Pu-erh tea knows that after eating beef, mutton, or a large meal of fish and meat, drinking Pu-erh tea speeds up digestion remarkably. In the past, there was a mistaken belief that the reason Pu-erh tea aids digestion and cuts grease was because the caffeine in Pu-erh tea stimulates gastrointestinal peristalsis, thus achieving rapid digestion. But that is not the real reason.

Scientists once conducted an experiment: placing several pieces of meat in a metal wire cage and having an eagle swallow it. After a period of time, the cage was retrieved. The meat slices were gone. This experiment shook the previous theory of digestion through gastrointestinal peristalsis. It was realized that there are certain substances in gastric juice that can digest meat, including gastric protease, saccharifying enzyme, etc. This experiment also indirectly refutes the theory that caffeine in Pu-erh tea stimulates gastrointestinal peristalsis to aid digestion.

During the fermentation of Pu-erh tea, its inherent cellulase and pectinase, interacting with other enzyme systems, decompose a large number of derivatives. These derivatives include not only saccharifying enzymes but also other enzymes that react with the biological enzyme systems in the human stomach and intestines, increasing the secretion of gastric protease, promoting the activity of gastric protease, enhancing the stomach's ability to digest protein foods, and thus strengthening the human body's digestive function. Therefore, Pu-erh tea's characteristics of cutting grease and aiding rapid digestion are the first features it conveys to consumers.

Related link: Efficacy and Effects of Golden Flower Pu-erh