Processing of Yixing Clay
NOTE: this post is out of date. Those Interested in Yixing Teapots are suggested to read An Introduction to the Art & Science of Chinese Tea Ceremony: Yixing Teapots – Knowledge, Connoisseurship, and Technique
The raw yixing dirt needs to be processed and refined before it can be fired into a beautiful, usable, teapot. The clay starts as a dusty, soft, colorful dirt and goes through 8 processing steps that can take up to 50 years to complete – the longer the clay is aged and rested, the higher the quality (and the less likely it is to break in the kiln from uneven shrinkage caused by impurities).
This process list only applies to higher quality yixing clay. Obviously, lower quality yixing clay (and fake or fraudulent clay) cuts corners and the aging and resting process.
- The clay-dirt is left out in the elements (for a long time) to dry. The particle size of the uncompressed clay is quite small, and the clay should be spread out over a wide area.
- The drying process (and mallets) breaks down the clay into even smaller particles. This makes it easier to sift and remove impurities.
- The Yixing continues to rest and soften for a minimum of 2+ years (usually about ~3 years).
- The clay is dry milled into sand. (this is where the term purple sand for Zisha Yixing comes from)
- The sand is sifted with water down to 30 microns (the laborers where respirator masks). This continues to remove impurities and pieces of yixing that haven’t broken down.
- The artist or yixing master blends refined sands from multiple areas. The mixture is usually secret, and only passed to apprentices in their final level of training (at least in the past… the nationalization of the yixing industry changed this, and now… some yixing artists have returned to using secret blends, but how secret they are is questionable). In the past, many yixings we’re made from clay from single mine – blending was rare. Now nearly all yixing teapots are made with blended clay.
- The clay is mixed and churned to the right consistency. Water is consistently skimmed off the top to continue removing floating impurities.
- The clay is kneaded, hammered, and thrown into a block. It is now ready to be used for ceramics.
Remember: the clay is the single most important attribute to consider when purchasing a yixing teapot. You should be purchasing the yixing teapot for its positive affect on the flavor profile of a single type of tea – and the clay is responsible for 99% of that effect. The shape and size matter much less than the purity, quality, and firing of the clay.