by Patrick and Siyan
We continue our series on Yixing clay, also known as zisha, by looking at Dicaoqing 底槽青, a kind of zini 紫泥 or purple clay.
Dicaoqing is one of the most well-known kinds of zini. It was originally mined from the now-closed no. 4 and no. 5 mines in Huang Long Shan 黄龙山 and is found when mining other zini. The ore of dicaoqing is easily identified by greenish grey spots, referred to as “chicken eyes” 鸡眼 jiyan. The low amount of oxidized iron in these areas causes the greenish discoloration in the ore.
What’s in a name?
The name for dicaoqing comes from where the miners would find dicaoqing while mining zisha ore. After deciding where to dig, zisha miners would dig out a trench or “trough” (槽 cao) to mine the ore. The common name for zini at that time was “qingni” 青泥. Dicaoqing was found at the bottom (di 底) of the trench (cao 槽) of qingni (青泥). The name dicaoqing 底槽青 roughly translates to “at the bottom of the qingni trench”.
Red or Purple
One of the interesting things about dicaoqing (although not unique to this clay), is how firing temperature affects the final color of the clay. The firing temperature for the clay is between 1150-1250°C. Between that range the color of dicaoqing changes drastically. Firing at a lower temperature, such as around 1150-1170°C results in a dark red that can be described as sienna or “pig liver red." Firing at a higher temperature results in a much darker color, closer to dark brown/purple.
A Clay for a Versatile Teapot
Dicaoqing can be used like a zini clay teapot. Zini or purple Yixing clay is favored by Chinese tea drinkers because of its versatility. Not as porous as duanni, but more porous than zhuni, dicaoqing, like all zini clay teapots, is seen as a good clay for most kinds of tea. We find that sheng and shu puer, green oolong, yancha, black tea, all do well in this kind of clay.
This is part 2 of our article about Zhuni Clay, a kind of Yixing clay or zisha used to make teapots in the town of Yixing, China. In this two part article we answer some of the more common questions we have received about this clay. To read the first part of our article, click here.
What is “Old Zhuni”?
When distinguishing “old zhuni” from “new zhuni” we first need to distinguish “old zhuni” from antique zhuni. “Old zhuni” lao zhuni 老朱泥 is a term from the zisha industry that refers to how long zhuni clay has been aged before it has been shaped into a teapot and fired. All zisha clay, zhuni included, has to be aged before it can be used. Aging the clay means that after the ore has been mixed with water and processed, it will be allowed to sit so that the organic matter in the mixture decomposes and ferments. Whether zhuni is old or new depends on how long it has been left to ferment. Zhuni left for 1-2 years is “new zhuni” xin zhuni 新朱泥. Zhuni left for 3 or more years is “old zhuni.” “Old zhuni” continues to be used today in Yixing. This is different from antique zhuni, which refers to zhuni teapots made long ago.
The zhuni that Wuyou Hall use to make the Yixing teapots we carry was stored for over 5 years and is old zhuni.
Is Zhuni Extinct? Did they close the mine?
We are often asked whether real zhuni is still available or whether it is “extinct.” Zhuni is not extinct, but it is rare. The myth of its extinction comes from the restrictions on zisha mining. Fear of overmining and environmental degradation led the Yixing government to greatly restrict mining operations beginning in 2005. All official mines were either closed or had their operations limited. This includes operations in the famous three spots: Huang Long Shan 黄龙山, Zhaozhuang 赵庄, and Xiaomeiyao 小煤窑.
Despite these restrictions, mining of zisha continues to this day. Zisha is still mined to a limited extent from official mines, but also from mines on the outskirts of Yixing, from construction and infrastructure projects in Yixing, and from “unofficial” mines in the town. The large amount of clay mined up until 2005, the need to age zisha before use, and the large size of the industry relative to the town, means that a certain amount of clay has survived in storage. This includes zhuni. A small amount of zhuni continues to be mined each year as well.
Zhuni is scarce compared to other zisha and it is in the interest of the people who sell the clay and make it into teapots to exaggerate how rare the material is. Stories that zhuni is extinct - except for a small amount that was hidden away by this one studio - circulate in order to drive up the price of teaware being sold.
How rare is Zhuni?
If we take Huang Long Shan as an example: Only 3-5% of the mountain is made up of Zisha ore; within that zisha ore, 80% is zini or purple clay, 12% is duanni, and only 8% is hongni. Zhuni makes up only a small amount of that hongni. It is still available and it is still being mined, but it is a very small proportion of the total amount of zisha ore being mined.
Within that tiny amount of zhuni there is an even smaller percentage that is “Da Hong Pao” zhuni, an extremely sought-after and extremely rare clay. It is estimated that around one in a million “Da Hong Pao” teapots being sold in the market are authentic.
How to avoid fakes?
There are lots of fake Yixing teapots in the market, and zhuni teapots are no exception. Because Zhuni ore is rare and very little is extracted each year, many fakes have flooded the market. These fakes attempt to mimic the appearance of zhuni using non-zisha clay, impure clay, chemicals and coloring mixed with real zisha or other clay.
Some of the fakes are easy to spot, others less so. Teapots that look very shiny before they have been used, that feel sandy or muddy to the touch, that have a bad or chemical smell, should all be avoided. Other selling points that sound too good to be true are also red flags. If a zhuni teapot is being sold for $50 USD or less, there is probably something wrong with it.
Fakes that use zisha clay mixed with some chemicals, other clay or coloring are harder to spot for someone who hasn’t used a real zhuni teapot before. Before getting into this business we had the misfortune of buying a fake zhuni teapot. It wasn’t until later when we had a lot more experience and were able to compare it to a real zhuni teapot that we noticed the texture and feeling wasn’t quite right. We stopped using the teapot as there is no way of knowing what was used to make it. After a long time looking at different teapots on the market, studying up on zisha and asking around and meeting with different studios we began to have a better understanding of the process of making Yixing teapots and of how to distinguish genuine Yixing and Zhuni from the fakes. After getting to know the owners of Wuyou Hall, seeing and using their teapots and observing their process, we decided to choose them as our suppliers because we know the products we are providing are genuine, safe, and a pleasure to use. The Yixing teapots, including a zhuni shuiping that we use daily, were all made by this studio.
Is Zhuni a mixture of clays? What is “original ore” zisha clay?
Original ore zisha refers to zisha clay that only contains zisha clay and is not mixed with any other kinds of clay, chemicals or coloring. It is safe to use.
At this point it is important to discuss mixing clay. It is important to distinguish between zhuni mixed with other zhuni clay, mixed with other zisha clay, and zhuni mixed with non-zisha clay and/or chemicals and coloring.
Different kinds of zisha clay are often mixed together before being processed. This is a normal practice in the industry and goes back hundreds of years. The people who process the raw ore before it is sold to potters often have recipes passed down through generations to produce zisha that will yield the desired textures, colors, characteristics sought by the potter and by the customer. Zisha mixed in this way is perfectly safe and does not have any harmful chemicals. Real zhuni used for teapots in the past and today, consists of clay that may be 1) zhuni ores from different mines mixed together (Huang Long Shan + Zhaozhuang + other mines), 2) processed zhuni mixed with unprocessed zhuni, 3) zhuni mixed with small amounts of other zisha (such as hongni). All of these processes are safe to use, however mixing with other kinds of zisha clay is perceived to have a negative effect on the texture, shine and character of a zhuni teapot.
The desirable and common way to mix zhuni is by using different sifters to sieve zhuni ore into different sized particles. Clay that is mixed in this way will show larger particles in the skin of the teapot (the different sized particles in the zhuni clay are referred to as “bones” and “meat”). If it is good quality zhuni, then no other mixing is necessary.
The zhuni teapots we sell are 100% pure zhuni.
The world of Yixing Teaware is full of myth, misconception, and exaggeration. It can be quite challenging for someone new to Yixing teaware to make an informed decision when purchasing a teapot. Of all of the Yixing clays, perhaps the most mysterious is Zhuni, the famous orange-red clay. A great deal of misinformation standing in for factual information makes it difficult for anyone who is interested in acquiring a zhuni teapot. We often receive questions from customers about this clay and will do our best to answer some of the most common questions below.
What is Zhuni?
Searching for information online one finds confusing talk of “old zhuni” vs “modern zhuni,” of zhuni being “extinct,” and the claim that “modern zhuni” is in fact “hongni” or a mixture of hongni and other Yixing clay.
If we are using the original definition of “hongni,” then zhuni is a kind of hongni. Hongni 红泥 means red clay and was used to refer to Yixing clay that was red in color after being fired in the kiln. The charater 朱zhu in zhuni refers more specifically to vermillion or cinnabar red, a bright-orange red hue. The term zhuni was applied much later to some hongni teapots that exhibited a number of characteristics that were much sought after for a group of Yixing teapot collectors. Hongni teapots that were bright orange-red or zhuhongse 朱红色 and which appeared somewhat silky to the touch and gained a brilliant shine from use, came to be called “zhuni” 朱泥in contrast to the other darker, rougher hongni clay.
Zhuni can also be separated from hongni from the appearance of its raw ore and from where the ore is mined. Zhuni ore comes from soft mudstone, hongni is a kind of sedimentary rock. Zhuni ore is fragile and when mixed with water is very smooth. Hongni is harder and sandier.
Hongni and Zhuni react differently when fired. All zisha will contract / shrink to a certain extent when fired in a kiln, but not all shrink to the same extent. The shrink rate of hongni is about 13%, however zhuni will shrink from 17-25%. The high rate of contraction means that zhuni is more likely to break in the kiln, and fewer zhuni teapots survive firing than other kinds of zisha. Although modern techniques allow the artists to optimize the process, making it possible to fire more pots without losing as many of them in the kiln, and even to make larger teapots, most studios still err on the side of caution and avoid making larger zhuni teapots, as they are more likely to break in the kiln. Most zhuni teapots are 160ml or smaller.
What kind of tea is good in a Zhuni Teapot?
Yixing Teapot tea pairing is very subjective, however it is generally agreed that Zhuni is better than other other kinds of Yixing clay (known as zisha) for fragrant teas, like Taiwan high mountain oolong. It works well with black teas and other higher roast oolongs as well. Compared with other zisha, zhuni is denser, has smaller pores, and traps less air between its pores. As a result, it is better at conducting heat and does not absorb fragrance as much as zini or duanni. The result is that it acts more like porcelain, losing heat faster, so it doesn’t overcook more delicate teas, and it holds the fragrance, concentrating it, unlike zisha such as zini and especially duanni, which are often favoured to help “round out” a tea with harsher notes, like a young strong sheng puer.
What is 'Old Zhuni'? Is Zhuni 'Extinct'?
Is Zhuni mixed with other clays?
How to choose a Zhuni Teapot?
Find out the answers to these and other questions in Part 2 Here.