For the average consumer, very few have a comprehensive understanding of the full process of ripe Pu'er Tea piling fermentation. This is partly because the stable bacterial colonies within piling fermentation workshops are so valuable that they are often treated as confidential by tea factories and strictly off-limits to visitors.

Even if one were allowed to visit, it would be difficult to conduct in-depth studies on each step, given that the entire piling fermentation cycle lasts for dozens of days and includes different processes such as watering, turning the pile, and ditching, making it a complex systematic project.

Moreover, since the decisive role in piling fermentation is played by imperceptible microorganisms, it does not resemble modern manufacturing with standardized procedures and quantifiable metrics but rather is more akin to a technique guided by empiricism.

From the minor details like controlling the workshop temperature to significant factors like timing the turning of the pile, many steps in piling fermentation lack quantifiable standards. The success or failure of each fermentation cycle is heavily dependent on the experience and adaptability of the fermentation master.

Today's article will guide tea enthusiasts through the general process of piling fermentation.

Selecting the Fermentation Site

The choice of site is crucial for piling fermentation. Since watering is required during fermentation, the site must be able to retain some moisture. When the pile temperature rises, excess moisture needs to be released promptly, so the ground should have good water absorption and permeability.

Therefore, traditional fermentation workshops often feature brick or rough concrete floors with a certain degree of inclination to allow excess water to flow away quickly and prevent the tea from spoiling.

Some tea companies, out of concern for food hygiene, have previously covered the fermentation pools with tiles. Although this can affect drainage, the gaps between the tiles do not significantly impact the overall fermentation process.

In recent years, tea enterprises have adopted more hygienic methods such as elevated fermentation using stainless steel plates or wooden barrels. After the floor is laid, it often carries an odor and lacks dominant bacterial colonies, so it cannot be used for fermentation immediately. Instead, the ground needs to be conditioned: first to eliminate odors and second to cultivate bacterial colonies to ensure the quality of the Fermented tea.

To condition the ground, a layer of leftover tea dust and broken tea residue (about 1 cm thick) from previous productions is spread on the floor. The area is then thoroughly watered, allowed to dry, and watered again to keep the surface moist.

Once the concrete floor has darkened from being saturated and the tea dust has lost its tea flavor, the conditioning is complete. However, new fermentation workshops may struggle to produce high-quality ripe teas, so lower-cost raw materials are recommended for the initial batches to minimize losses.

For premium ripe teas, if the raw material costs are high, many tea companies will lease fermentation workshops that have been in use for many years to ensure stability in the microbial phase.

For example, the renowned 2004 Fugeng Peacock Banzhang Ecological Tea, commonly referred to as “Fugeng ABCD Piles,” was fermented at Menghai Tea Factory and pressed at Xinghai Tea Factory. It is known for its rich, smooth taste and high Sweetness, and is highly sought after in the market.

After the reform of Menghai Tea Factory, which no longer accepts custom processing, the He brothers once borrowed the Xinghai Tea Factory workshop to continue fermenting Banzhang ripe tea until the Fugeng brand was established and their own fermentation workshop was built.

The following Xinghai 2006 Banzhang King Pu'er ripe tea, which was fermented in the same workshop, has a smooth, delicate taste with a hint of lotus fragrance. It offers excellent value for money and is highly recommended.

Due to the climate and environment of the workshop location, the initial fermentation cycles may not always yield satisfactory results. In such cases, the person in charge must decide whether to recondition the ground or seek another location.

Piling Tea and Watering

Once the site construction is complete, production can begin. The first step involves piling the tea, which involves two key technical points: the height of the tea pile and the amount of raw tea used.

The height of the tea pile typically ranges from 50 cm to 120 cm, with quantities ranging from small piles of 100 kg to larger ones of tens of tons. There is a wide variation, partly due to different factory practices and partly because of the varying grades of raw tea in each fermentation batch.

Generally, the older the tea leaves, the higher the pile, as coarser materials have loose, large strands that are well-aerated and absorbent. Conversely, finer materials are more compact and less aerated, which will be discussed further in the watering process.

After the raw tea is piled, it is time to water. Early watering methods were quite crude, involving a hose connected to a tap, with one person spraying the tea pile while another monitored the water meter until the desired amount was reached.

With improvements in production technology, most now use mist sprayers to water the tea, and a combination of watering and turning the pile is employed to ensure the tea is evenly moistened.

One detail to consider is that water naturally flows downward, causing the bottom of the pile to become overly wet and clump together. If watering is done in the morning, the pile should be turned in the afternoon, and again the next morning, to distribute moisture evenly.

The two most important parameters in the watering process are the amount of water and the water quality, both of which are influenced by numerous factors such as the moisture content of the fresh leaves, the grade of the tea, and the season of production. These factors greatly test the experience of the fermentation master.

The typical ratio of raw tea to water is around 3:10 to 5:10, with the moisture content of the raw tea ranging from 28% to 35%. Finer teas have higher moisture content than coarser ones and thus require less watering; similarly, during the rainy season, when humidity is high, less water is added.

The amount of water determines the success of the fermentation, while the water quality influences the quality of the fermentation. Due to the benchmark effect of the “Menghai flavor,” the industry largely references the pH level and microbial content of groundwater in the Menghai region when fermenting ripe teas.

Aside from the story of the “Menghai No. 1 Well,” the Menghai region boasts superior ecological conditions and relatively pure groundwater, which is highly compatible with the microorganisms in fermentation workshops, making it an excellent source of water for watering.

However, considering its irreplicability, the industry seeks a more universal and cost-effective source of water, such as recent research showing that deionized water is well-suited for ripe tea fermentation.

The deionized water referred to here is not a health gimmick marketed by merchants but specifically refers to purified water free from ionized impurities, which is not adsorbed by macromolecules within plant cells and can influence the physical properties of protoplasm.

This is because the water content in tea leaves consists of free water and bound water. Deionized water can crystallize with free water and transform bound water into free water, maintaining “water activity” (Wateractivity).

In the modern food industry, represented by alcohol production, deionized water has seen widespread use. The most advanced intelligent fermentation by Dayi also uses deionized water, which will see more application in future ripe tea fermentation.

Piling and Aeration