How many times have you heard about the terms stoneware, porcelain, clay pots, pottery, ceramic coated cookware, but you haven’t been sure what all of these terms mean exactly, or do some of them be used as synonyms?
By looking around the articles on the internet, I was surprised by the number of misleading articles that tried to cover this topic. This is why I decided to write this post and bring some clarity to this matter.
In this article, I will go deeper into what the term ceramics covers and how it is related to/different than porcelain.
To bring you the information for this post, I left my theoretical knowledge about porcelain. And I went to some of the porcelain galleries in my city as well as the big retail stores of ceramic materials to bring more information about this topic.
But first, let’s shortly make the difference between these two terms. What is the difference between porcelain and ceramics?
Ceramics is the term for a broader group of materials to which porcelain also belongs. Production of ceramic cookware also known as pottery encompasses a wide set of materials and techniques for their production, where the three main ones are porcelain, earthenware, and stoneware.
In this post, I will bring you some insides into how porcelain is produced and why it is different from other types of ceramics in terms of appearance and performance.
During my stay in the porcelain gallery, I have the chance to see how this amazing material is made and why it is so valued in society. Moreover, I am looking forward to sharing about it with you in this post.
So let’s go straight to the topic.
1. What is the difference between ceramics and porcelain?
Nowadays, many utensils have the word “ceramic” in its name, even though they are not made from ceramics at all.
A great example of this is massively advertised ceramic-coated cookware. I won’t talk about it deeper in this post since it doesn’t belong to real ceramics. However, if you are more interested in what ceramic-coated cookware is and how it differs in composition and production process from real ceramics you can take a look at my in-depth article.
Ceramic cookware production is a broad term that encompasses different techniques and materials including the production of porcelain.
Ceramics is material made from thermally processed clay, which is soil material consisting of very fine-grained minerals, mainly silicon and aluminum oxides.
During the thermal processing of clay, ceramics is formed. Moreover, depending on the type of clay used(which can vary in mineral composition to some extent) and the temperatures applied, different forms of ceramics are formed. The three main ones are earthenware, stoneware, and porcelain
Earthenware requires the lowest firing temperatures, and the highest temperatures are required for porcelain, while stoneware is processed in the middle-temperature range between these two.
If you’re interested deeper in the clay and clay minerals as well as how they are transformed to form ceramics during thermal processing you can take a look at my article here.
So, let’s turn back to the main question. How do porcelain production and composition differ from other ceramic types?
In one of the amazing galleries that I visited called Boya porcelain, I have an opportunity to hear more about porcelain production from people who have years of experience in this field. As mentioned, compared to other ceramic materials porcelain is thermally processed at the highest temperatures.
This is an example of a kiln for the thermal processing of clay and producing porcelain
Even from some literature in the past, I knew that porcelain is produced in the temperature range of 1200-1450C/2200F-2650F(reference), in this gallery they have used a lower range of about 1250/2300F.
Unlike porcelain, other ceramic types like earthenware and stoneware are produced at lower temperatures (Lower than 1200C/2200F).
During the heating process, some of the clay minerals melt and form a glass structure. Clay is naturally very porous, however, in porcelain production melting happens to a full extent so the final material loses porosity(unlike in stoneware and earthenware production where lower temperatures are applied) .
Finally, because of its nonporous structure, porcelain is much more resistant to soaking water, and it has longer durability compared to the other two ceramic types.
As I could hear from one of the Boya Gallery founders:
“When archeologists in China dig out some porcelain piece from ancient Chinese dynasty, it is enough to clean it a little it and it is ready for use”
I get it just like another story to emphasize the durability and strength of the porcelain
Additionally, the clay mix used for porcelain production is different from the clay for the ceramic types. It usually contains a high percentage of kaolin. This substance is one of the clay minerals, very important in forming the glassy porcelain during the firing process.
When I was discovering one of the biggest ceramic material retailers in my country, I could see how they separate the raw clay sold for porcelain from clays sold for all other ceramics.
Down below, you can see the raw clay material used just for porcelain on the left, which is kaolin-rich clay coming from Limoge in France (one of the places with the biggest tradition of porcelain production in Europe). Clay mass that can be universally used for other ceramic materials (earthenware and stoneware) is on the right.
So we clarified how the porcelain production process and key ingredients differ from other ceramic types. Now, I will show the difference between them in the context of appearance.
2. How does porcelain differs from other ceramic cookware in its appearance?
I have asked this many times to people who work with porcelain and other ceramics for a long time. Moreover, I wanted to make a visual representation of what I have learned
The graphic below will demonstrate some tips on how to differentiate porcelain cookware, and dinnerware compared to other types of ceramics(Stoneware and earthenware).
It will be good to say that not all of these signs will apply to each piece of porcelain, however, you will observe at least some of them when looking at the porcelain.
Porcelain can be thinner– Porcelain is a more compact, harder material that can be shaped thinner than other ceramic types. This doesn’t mean that some porcelain pieces aren’t made to be thinner. However, if you see a plate, cup, or bowl that is thick 3-4mm you can be pretty sure that you have porcelain.
These extremely thin porcelain pieces are made from a special type of porcelain called bone china.
Bone china is a particular type of porcelain where kaolin-rich clay is also mixed with powdered bones(commonly derived from cows as I have learned in the porcelain gallery) that give extra flexibility to the material. This allows the formation of very thin walls of cookware and tableware made from this material.
Since porcelain is produced under higher temperatures than other ceramic types, the clay minerals in raw material vitrify to a further extent and become less porous. Find more about how clay is transformed into ceramic in my post here.
This can be seen when you compare glazed pieces of porcelain with other ceramics.
On the other hand, if you want to observe this in glazed pieces, their bottom is usually non-glazed so you can touch it to determine the porosity.
The good practice will be to go to a dinnerware shop and take several plates from porcelain and other ceramics(e.g. stoneware which is common) and touch several dinnerware bottoms to feel the difference in porosity.
Porcelain can be transparent- There is a common misconception that all porcelain is transparent(light can pass through it) when you face it towards a strong light source(e.g. light bulb).
The transparency depends on the thickness of the porcelain and the color used for finishing of color pieces. Even some dark finished or thicker porcelain pieces are not transparent in several cases you will be able to see light transparency as has been shown in the plate example on the infographic.
However, dinnerware and cookware from other ceramics is rarely transparent regardless of their thickness and color.
Resonance-As mentioned porcelain is a very compact and hard material and this has its effects on the way how it sounds after being knocked with another hard object (e.g. metal utensil). Usually, it gives a sound like hitting the bell or a resonance fork. On the other hand, you are not going to observe the resonance sound to such an extent with so with dinnerware/cookware from other ceramic types.
*I find that feeling this difference is not always easy. Notice that the shape of the dish/cookware piece affects the sound you can get. So in order to observe the difference in resonance sound it would be good to have two dinnerware/cookware pieces of similar size and shape(e.g. two flat plates)
3. Bottomline
In final words, One common thing about ceramics regardless of their type is that they can be a quite safe material for applications in cookware and dinnerware compared to some metal and nonstick utensils. I have written a depth article about pure ceramics safety where you can find comprehensive information on this topic.
Porcelain is a very inert, hard, and durable material with a long history of production.
However, even is superior material when it comes to the production of tableware its applications in producing cookware are not wide(mainly bakeware).
In the cookware world, earthenware, and stoneware are much more in use. Additionally, these materials bring some special advantages to cooking including the preservation and identification of the dish aromas and taste, preservation of food moisture during cooking and.
To find out more about that you can take a look at my article where I have compared exactly the same dishes prepared in pure ceramic and metal utensils. Moreover, you may be interested to see my myth-buster post about pure ceramic cooking advantages. There I presented experiments to prove/deny some of the common beliefs bout pure ceramic cookware cooking benefits.
