Ash is also known as ash covering, which is an ancient term for pot-making technology. It refers to the secondary low-temperature firing on the surface of the teapot after firing, with the purpose of repairing the defects in the firing process, or giving the pot body a more outstanding visual effect. The use of this technique can be traced back to the Yuan Dynasty, and later carried forward by the craftsmen of the Ming and Qing dynasties, and became a major "unique activity" of purple sand firing.
Nowadays, the industry often miswrites the ash as "ash". In fact, the word "cover" is more accurate, it reflects that this is a kind of strict burial, in the environment of isolation of the air for the reduction reaction process. This misunderstanding may be due to the negligence of later generations, but it also reflects the difficulty of inheriting this skill. After the vicissitudes of life, there are very few masters who can carry it forward from heart to heart.
The charm of the ash pot is that it is very different from the color of other purple sand ware. The general purple clay pot is fired under aerobic conditions and appears red or blue-gray. The ash pot undergoes a reduction reaction in a low-temperature anoxic environment, with a color like black jade and a quality like iron stone. Such a unique black color is just like the thick ink and heavy color of the Tang and Song Dynasty ink writers, exuding an intriguing charm.
The predecessor of the ash pot is often the "loser" of the first firing of the first flaw. It is recorded in the "Zisha Record" that the pots fired by Gong Wen in the Yuan Dynasty often have defects such as flower mud, dark spots, and cracks. To compensate for these imperfections, he re-fired the finished product in a kiln and finished the ash under the cover of rice bran. In this way, the marks on the pot are obscured and the color becomes uniform.
I can't help but think that in Gong Wen's heart, his works must have been entrusted with countless painstaking efforts. No matter how small the flaws are, they will definitely touch his heart. So after the failure, he chose to remedy the situation and re-burn the pot in another process.
This reminds me of the process of Japanese potters repairing broken tea bowls. They say that the fine metal is like the meridians of people, and they reflect the spiritual connection between people across time and space. Craftsmen see themselves as inheritors of nature and the wisdom of their ancestors, and with unswerving devotion to repair those broken containers, bringing them back to life and giving them a new lease of life.
I think that in Gong Wen's heart, his purple sand works are also full of such precious vitality and emotion. They are the overflow of his heart, carrying his dedication and love for this ancient craft. Therefore, even if he fails, he still does not give up, and only hopes to be able to regenerate the work in a different way. This kind of ingenuity is admired by future generations and teaches people to think deeply.
The technique of burning ash has gradually changed from a "remedy" to an aesthetic decorative technique. This is something that the craftsmen have gradually discovered over the years of practice. The ash can not only cover up the imperfections, but also make the color of the pot exceptional.
I once saw a stone scoop after the ashes. It is jet black all over, with a delicate and warm texture without any roughness. This is the unique charm of the ash - it gives the pot a warm and inky color and a solid texture like iron and stone. When future generations read the poem "Daguan Ti Wujin", they will definitely think of such a purple clay pot.
Nowadays, the ash technology is becoming more and more mature, and the success rate is getting higher and higher. More and more craftsmen no longer see it as acrobatics, but as a regular decorative technique. This reflects the inheritance and development of ancient craftsmanship from one side, and we can't help but feel gratified by it.
However, the hardships are difficult for outsiders to see. The requirements of the baking technique are extremely high, and the grasp of the heat and process all test the craftsmanship of the craftsman. Some people simply took a trick and mixed chemical raw materials into the mud to imitate a similar black pot. But that kind of work, the texture is uneven, and it loses the agility and profundity of the real product. It is difficult for beginners to distinguish between authenticity and falsehood, and they are often deceived by profiteers.