Different clay materials are needed to make purple clay teapots, and teapots have different air permeability, which can produce different flavors of tea. Among many mud materials, the one with the highest air permeability is Duan mud. As the “King of Breathability” among mud materials, what are the advantages of Duan Mu? What should you pay attention to when purchasing a clay pot? Let’s take a look together !

What is Duan Ni?

Duan Ni is also called "Tuan Ni" and is produced in the mining areas around Huanglong Mountain. "Duanni" is a general term, which is subdivided into many types of Duanni, such as Benshan Duanni, Huanghuangduanni, Sesame Duanni, etc. Generally, the color of Duan clay is more diverse among many clay materials, ranging from golden to blue-gray, so it is easier to distinguish Duan clay pots from other clay pots in appearance.

Duan mud is one of the symbiotic mineral sources in purple sand mud. It is symbiotic with green mud and purple mud, so it has the characteristics of both mud materials. Sectional mud is usually located under the roof of the deposit, above the purple mud layer, and will also be mixed in the purple mud layer. The distribution of section mud may be slightly different in different mining areas, mines and mining locations.

(Image source: Taohuren)

Why does Duan Mud have high air permeability?

The air permeability of purple clay material needs to be determined by both the "mesh number" and "crystallinity" of the clay material. The larger the mesh number of the mud material, the finer the particles of the mud material and the lower the air permeability. The smaller the mesh number, the larger the mud particles, and the higher the air permeability. Red mud materials such as vermilion mud generally have a higher mesh number, a more delicate texture, and low air permeability, so they can produce excellent fragrance. Purple clay and Duan clay can be used to make pot-making mud with a lower mesh number. The graininess is more obvious, the feel is slightly rougher than that of red clay pots, and the air-repellent effect is better.

The crystallization of the mud will also affect the breathability. The higher the crystallinity, the lower the air permeability. Red mud has the highest degree of crystallinity, followed by purple mud, and finally green mud and section mud. Therefore, under normal circumstances, the air permeability of section mud is higher than that of red mud and purple mud.

Why do Duan clay pots come in many colors?

There are two main reasons for the variety of colors of Duanni pots: the type of Duanni and the firing temperature. Because of the symbiotic minerals, the iron content in various sections of mud will be different, resulting in differences in the color of the section mud, which may be yellow, green or cyan. The color of clay with high iron content will be reddish, otherwise it will be yellowish or brown.

Another reason is that the firing temperatures Duan Mu can withstand vary greatly, generally between 1170-1200 degrees Celsius. The color of the clay pot fired at different temperatures will be different. The color of the clay pot fired at low temperature is usually lighter. The higher the temperature, the color of the pot will be bluish or even gray after firing.

(Different types of clay have different colors, and the firing temperature can also affect the color depth of the teapot.)

Is it true that Duan Nihu is prone to "vomiting black"?

Some users have found that after being used for a long time, Duan Mu pots are prone to "black spitting out" phenomenon, and some black spots or black lumps accumulate on the pot body and spout. The "black" appearance of the clay pot is mostly due to insufficient firing temperature, or it may be that the structure of the clay material is loose and the pores on the wall of the pot are too loose. Tea juice penetrates into the purple clay pot through the pores and accumulates to form scale.

In fact, red clay and purple clay pots can also experience the phenomenon of "black spitting out", but the color of the pots is darker and difficult to detect, while the color of Duan clay pots is lighter, and black spots will be very conspicuous once they form. Therefore, users should clean the pot frequently to prevent the pot body from spitting out black. When brewing, you can also choose lighter tea, such as fragrant Tieguanyin, green tea, etc., to avoid obvious tea stains caused by dark tea soup.

(Picture source: Puer Tea Network)

The above is a brief introduction about Duan Ni. Duan Ni teapots have high air permeability and the mud material is bright in color, so many people like to use Duan Ni teapots to make tea. Because the color of the teapot is light, you must not be careless when caring for the clay teapot. Clean the purple clay teapot carefully after use to prevent your beloved teapot from turning black!

Suggested reading:

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