
Why should you use a Yixing teapot?
Hey everyone! A lot of people ask if there is a real difference when it comes to teapot materials, or if it is just marketing hype and universe energy pseudoscience.
To be honest, the difference is real, and it’s pure science, not magic. So let's skip the talk about cosmic energy that will make people live forever, and just look at the raw chemistry and physics of the materials.
Porcelain, Coarse Pottery, and Yixing
To understand this, we have to look at the firing temperatures and absorption rates of the three most common brewing tools.
First, you have Porcelain. It is fired at around 1300 degrees Celsius and has a 0% water absorption rate. This means it has absolutely zero breathability. It conducts heat incredibly fast, so your high temperature extraction window is very short.
Next, you have Coarse Pottery. This is fired much lower, usually between 800 and 1000 degrees Celsius. It has a massive water absorption rate of 12% to 38%, which means it can actually leak water quite easily. Very few people use raw coarse pottery to brew tea today. A few years ago, those low temperature, wood fired Japanese teawares called Bizen ware were trending because they get that natural ash glaze in the kiln, but I have never personally used them so I cannot say too much about it. Their common shapes include Houhin and Katade, which are Japanese names. The problem with coarse pottery is that too many open pores create an over absorption effect, which causes a huge loss in tea fragrance.
Then you have Yixing. It is fired between 1150 and 1200 degrees Celsius, resulting in a tiny 2% to 5% water absorption rate. Yixing is technically a type of stoneware, and its vitrification level sits perfectly between porcelain and pottery. Depending on the specific clay ore and the grit size, it creates different levels of porosity.
How the clay alters the taste
Because porcelain does not absorb flavor and dissipates heat quickly, porcelain vessels, especially Gaiwans, are perfect for high aroma teas, or what I like to call "flawless teas." It hides nothing and changes nothing, which is why it is great for evaluating a tea's true state.
I attended a national level competition in Hangzhou, China before Covid. All the members of the tea jury used white Dehua Gaiwans to judge the quality of different teas. I asked why, and one nice lady from the Chinese Academy of Agricultural Sciences said that porcelain can reveal or expose the flaws of the tea honestly.
To really understand the science behind this, I spent some time reading a food science paper titled "Effect of teapot materials on the chemical compositions of oolong tea infusions," which I’ve referenced at the very end of this post. The lab data inside is wild, and it actually proves exactly what we feel when we brew.
Yixing clay, on the other hand, is able to minimize the loss of tea aroma while actively absorbing a huge amount of bitterness, astringency, and storage staleness. According to the study, the unglazed, uneven double-pore structure of Yixing clay acts like a molecular sieve, serving as a perfect gateway for mineral and flavor interaction.
To show you what I mean, let’s look at the actual data from the paper.
As you can see from charts, these loss ratios for amino acids, EGCG, and aroma compounds are very real. Also, porous structure slows down the dissipation of temperature inside the pot, effectively lengthening your high-temperature extraction window.
The Myth of "One Pot, One Tea"
You should know that Yixing clay is not suitable for every single tea on earth, and it is a myth that a pot can only brew one single type of tea for its entire life.
However, for every specific tea, there is definitely one perfect pot out there. But finding that perfect match is where things get wild, because during the processing, making, and firing of Yixing clay, the porosity changes in ways that are highly uncontrollable.
For example, if you grind the particles a bit finer during clay preparation, the porosity drops. If you build the pot using the traditional full handmade paddling method, the porosity increases. If the kiln temperature fluctuates by just one or two degrees during firing, the porosity drops again. Because of this, you sometimes get a fully handmade Zhuni pot where the clay was processed natively, and its breathability ends up being way better than a half handmade Zini pot.
This lack of control is the open secret of the industry. It is 2026, and yet nobody in the Yixing teapot industry wants to do any standardization. Even the most basic, controllable aspect like the raw material is left completely unstandardized. Don't even mention the craftsmanship, nobody regulates FHM versus HHM claims.
So for me "one pot, one tea," means every batch of clay behaves differently, general rules are just loose guidelines. Your specific tea leaves, whether they are new or aged, light roasted or heavily roasted, will interact uniquely with the specific porosity of your individual pot.
Why lots of modern pots have no pores left
To be fair, some Yixing clays look very smooth, bright, and beautiful even before you use them. For instance, with Jiangponi (mine from Baoshan), the red and green granules are naturally soft and loose. If you apply just a little bit of force with Mingzhen, those granules break down instantly. This is why a teapot made from it looks incredibly glossy after the Mingzhen polishing process.
But nowadays, buyers are completely obsessed with "water gloss," which is the instant out of the box surface shine of a teapot. To cater to this beginner aesthetic and drastically ramp up production, the mass market now relies heavily on a processing method called Chong Jiang (冲浆), or clay-slurry flushing.
Slurry flushing means flooding the clay with ultra fine liquefied clay silt. This dramatically increases the surface gloss of the teapot, sometimes creating a complete vitrified glass layer on the outside. These pots are incredibly easy to make, they do not crack in the kiln, and they rarely show any visual flaws.
But this process completely seals the gateway for mineral interaction and blocks any pore breathability. Physically, the clay has completely vitrified. Brewing tea in it is functionally identical to brewing tea in a glass cup.
I once did a crazy experiment on my own out of pure curiosity. Even with a dense, fine clay like Zhuni, when it is kept as raw, unadulterated ore, its smallest natural particles are still larger than 600 mesh. That means the clay still keeps its natural grainy structure. But slurry flushed Chong Jiang clay? It is so artificially pulverized that it can easily pass through my finest 1000 mesh filter cloth, and 1000 mesh is the absolute finest filter cloth I can find. It becomes as completely fine as some finest flour, leaving zero room for the clay to breathe.
So if you are looking to buy a Yixing teapot to actually improve your tea experience, make sure avoid slurry flushed pots at all costs. Otherwise, you are just paying a premium price for a disguised porcelain pot.
Anyway, that’s the reason for me to use a yixing to try different types of tea, to find pleasant surprises during the tea brewing. Please feel free to drop a comment and AMA!
References
- Haujo, T., & Jin, S. (2017). Effect of teapot materials on the chemical compositions of oolong tea infusions. Journal of the Science of Food and Agriculture, 97(11), 3701-3707. doi.org