Pu'er Tea, renowned for its characteristic of improving with age and thus being referred to as “drinkable antique,” not only requires high-quality raw materials and a complete production process but also needs an appropriate storage environment. The natural post-fermentation of Pu'er tea involves many aspects, and storage conditions will directly impact the drinking quality of Pu'er tea, affecting its color, flavor, and aroma.
Storing Pu'er tea is very particular.
A high temperature and humid environment can easily cause mold.
Therefore, when storing Pu'er tea,
humidity should be controlled below 70%.
Temperature should be maintained around 20°C-28°C.
Avoid exposure to light and store in a sealed container.
Raw and ripe teas should be stored separately.
Nowadays, more and more people are drinking Pu'er tea.
What kind of vessel should be used for storage?
The answers vary widely.
A popular saying is that “Jianshui purple clay pottery is a perfect match for Pu'er tea,” but there was no scientific data to support this until now.
The Shanghai Jiao Tong University – Jianshui Purple Clay Joint Research Center conducted research on the integrated development of Pu'er tea and Jianshui purple clay pottery.
The research concluded that Jianshui purple clay pottery has the capability to regulate humidity, which is beneficial for the storage of Pu'er tea.
The paper “Analysis of the Raw Materials and Moisture Retention Performance of Yunnan Jianshui Purple Clay” has been published in the authoritative domestic journal “Journal of Ceramics” (Volume 44, Issue 1).
The paper indicates that the Shanghai Jiao Tong University – Jianshui Purple Clay Joint Research Center conducted comparative experiments on temperature and humidity changes when storing Pu'er tea using Jianshui purple clay pottery in Kunming, Shanghai, and Chengdu. When indoor humidity drops below 30%, the humidity inside the Jianshui purple clay Jar remains at 45%-50%. When indoor humidity exceeds 75%, the humidity inside the Jianshui purple clay jar remains at 60%-65%.
To explain this phenomenon, the Shanghai Jiao Tong University – Jianshui Purple Clay Joint Research Center analyzed the phases, particle size, and sintering structure of the original ore, clay, and finished product of Jianshui purple clay through X-ray diffraction, scanning electron microscopy, thermogravimetric-differential scanning calorimetry, mercury intrusion, and particle size measurement. The moisture control performance of Jianshui purple clay is closely related to the particle size of its clay and the pore characteristics after firing, based on a comparison of the chemical composition and microstructure before and after firing.
Through the research, it was found that the particles of Jianshui purple clay are generally finer, with smaller pore diameters and narrower pore size distribution after firing. Its “breathing” performance with water vapor lies between impermeable glass and porous purple clay. For Pu'er tea, this ensures that fermentation does not occur too quickly while maintaining the activity of enzymes and microbial flora within, helping Pu'er tea achieve its characteristic of improving with age.