Jianshui purple pottery is made up of pure natural clay, and the main elements are iron, with trace zinc, silicon and ferocious elements.
The mesh number of clay is about 250 mesh, which may be a little strange to you. Let me give you a proper example. The clay with 250 mesh is equivalent to the facial cream our female friends wipe.
The molding method is mainly formed by casting. In addition to the rapid forming, there is also a very important “softness”, which just breaks the “rigidity” of purple pottery clay. Why is the purple pottery clay “rigid” because the mesh number of purple clay is very fine, so the mutual suction of the soil in the process of dewatering is very large, so that the state of the soil before casting is very high It is dense and the air permeability of the mud door is not high, so the clay of purple pottery is a piece of iron when it is made.
In the process of forming the revolving green body, the green body is constantly increasing and becoming full, and the asymmetry of gesture is stretching the mud door of the soil, which makes the originally dense mud door loose in the change of the green body.
This is just the opposite of Yixing purple sand. Because the soil is loose and the mesh number is relatively low (usually between 60 and 80 mesh), it needs to be chipped and shaped, that is, the compactness of the soil is increased by repeatedly beating. Jianshui pottery is to reduce the density of soil by casting.
It can be visually observed that the body of Jianshui pottery is honeycomb after it is formed. After two weeks of natural drying, the green body can be fired in the kiln. After high temperature firing, the body structure of purple pottery still presents a single pore honeycomb shape.
As we all know about the chemical elements and firing structure of purple pottery, let’s talk about the relationship between purple pottery and Pu’er tea. We all know that Pu’er tea, as a special kind of tea, is also very important for Pu’er tea. What kind of storage and transformation environment is needed for Pu’er tea?
In my opinion, the balance of temperature and humidity is the key to the storage and transformation of Pu’er tea.
At present, there are various storage dishes on the market, including Jingdezhen porcelain and Yixing purple sand.
Due to the glaze, the surface of porcelain is glassy, so it is easy to form a sealed environment which is relatively free from external interference. This environment is conducive to the storage of green tea, so that the aroma of green tea can be maintained longer; but it is not conducive to the storage of Pu’er tea, because it is impermeable, resulting in the inability of Pu’er tea to breathe and transform.
What about purple sand utensils? Good air permeability and low density are conducive to the transformation of Pu’er tea. The answer is also wrong, because it lacks a long-term constant temperature environment. The storage and conversion of Pu’er tea is not completed overnight, but needs a long storage time to facilitate the transformation.
Due to the low mesh number of purple sand, the green body structure after firing presents a double porosity environment. This environment is not tight for a short time, but not for a long time. The environment in the utensils is easily disturbed by the surrounding climate. Too dry or too humid is not conducive to the transformation of Pu’er tea. Once the air humidity is high in plum rain season, Pu’er tea cake will become soft and moldy Tea friends in the South should have the most experience. So purple sand ware is not the best storage dish.
Purple pottery is left. As mentioned just now, the green body of purple pottery is honeycomb with single pores, but the density is relatively high. The vessels made of this kind just provide a microcirculation environment, which is neither airtight nor airtight like porcelain, nor too airtight like purple sand.
In such a microcirculation environment, there is little interference from external factors. When the climate is dry, it can have relative humidity. In the season of high humidity, because its single pore can provide a relatively dry environment, these two points just meet the storage environment of Pu’er tea, that is, it can provide a relatively constant temperature and microcirculation environment for long-term storage of Pu’er tea.