Zisha clay is incredibly rare and has been excavated from deep, underground sources within Yixing County, China since the Song Dynasty (960-1279). Composed of various minerals, the clay’s characteristic coloration is derived from an unusually high concentration of iron oxides. In turn, these colors can be enriched or altered through the careful addition of additional oxides during the material’s precise processing.
Once the clay has been removed, it is sun-dried and worked to remove impurities and create uniformity. This process is closely monitored, and exacting standards are kept for the maintenance of proper water quantity and quality in order to guarantee successful firings.
Oxidizing atmospheric kilns strictly maintained at a temperature between 1100°C and 1200°C (2012°F and 2192°F) are used to fire bone-dry Zisha ceramics, which are hand-built. Final adjustments to the kiln atmosphere and subtle, skillful tweaks to temperatures during very specific stages of the firings can also yield dramatically different results in coloration.
After firing, Zisha ceramics remain in a semi-porous state. It is for this reason that tea pots made from the material have been both highly sought after and regarded throughout history. Because these tea pots absorb trace amounts of the liquid they hold, they enrich tea flavors, imparting depth and complexity. For this reason, it isn’t uncommon that each Zisha tea pot be used for only one particular variety.
Gary Wang, the company’s late lead designer, with family roots in Yixing, the traditional home of the clay and its craft, shared both a passion for and connection to Zisha’s past. Many of Spin's Zisha designs are based on his family heirlooms re-interpreted.