The phrase “this purple Clay teapot has been fired multiple times” is often seen. Does this mean it wasn't fired properly the first time, so it had to be tried again? Actually, that's not the case.
So why were older purple clay Teapots fired only once, while modern ones are fired two or more times? Is it better to fire them once or twice?
When Were Teapots Fired Just Once?
Before the Republic of China period, local artisans in Dingshu hadn't yet adopted modern Kiln-firing techniques and mostly used Dragon kilns. Dragon kilns have poor controllability, and each additional firing increased the risk of damage. Therefore, older teapots were typically fired just once. As a result, the lids rarely fit tightly, unless the potter was an exceptional master who understood the clay's properties perfectly. Such masters were rare.
Why Are Modern Purple Clay Teapots Fired Multiple Times?
With advances in modern technology, new kilns like shuttle kilns and electric kilns have become common, allowing for precise temperature control. With higher standards for craftsmanship, a second firing became standard practice to ensure a tight lid fit. The first firing is at a lower temperature. After the teapot comes out of the kiln, the lid is polished with carborundum. It is then refired at a higher temperature, resulting in a teapot where the lid fits snugly. This process is known in the industry as “adjusting the lid.” The second firing reaches the crystallization temperature of the clay, completing the teapot. Sometimes, if the color of the clay isn't satisfactory after the second firing, a third firing is performed.
The more times a teapot is fired, the higher the degree of crystallization will be, but the risk of damage also increases. The teapot must not be soaked in water after the first firing, or problems will arise during the second firing. “Double firing” refers to the process of adjusting the lid and removing firing flaws after the initial firing, followed by applying fresh clay to the polished areas (known as “breaking the skin”), and then performing a second firing. The fresh clay forms new crystals when rubbed on, which makes any imperfections invisible after firing, resulting in a nearly perfect teapot.
Whether a teapot is fired once, twice, or even three times, the end goal is to produce an object as close to perfection as possible. Such skill and dedication are commendable.