What is the difference between Miriams Earthen Cookware’s pure clay pots and all other cooking pottery: ceramic, porcelain, stoneware, flame ware & terracotta?
Ceramic and porcelain: From making toilets to tiles to cooking pots, the ceramic material has been used for various uses and is sometimes called ‘clay’ because of its elasticity. 90 to 95% of its composition contains chemicals, oxides (obtained through fracking) and inorganic substances (through mining). These are then processed to form the ceramic or porcelain material in an environmentally detrimental manner. The other 5-10% may contain natural clay like kaolin. A typical mixture could contain over 75-200 different chemicals and oxides, some of which are listed here: Chemicals, toxins, oxides and inorganic substances in ceramics.
The unique combination of chemicals depends on the final product and is usually a well kept secret. For example, if being made into a cooking pot, the chemical petalite is added at a certain percentage (this is an ore of lithium), to control thermal shrinkage. Because it’s a combination of elements sourced from different ores it has to be fired to high temperatures to fuse these elements together. Because of the presence of dangerous chemicals this ware always needs to be glazed.
Flame ware: Flame ware is also a name given to ceramic material used for making cookware that has specific chemicals added to withstand heat. This raw material may or may not contain any real, natural clay. And typically contains toxic chemicals including petalite, an ore of lithium. Because of the presence of dangerous chemicals this ware also always needs to be glazed before using for food.
Stoneware: has a higher percentage of natural clay, typically up to 40% and the rest of the raw material is a combination of chemicals, oxides and some toxic additives. Because they have a greater percentage of natural clay, their firing temperature is less than ceramics or porcelain. Because of the presence of chemicals this ware also needs to be glazed before being used for food.
Terracotta: Terra + Cotta or “cooked earth” is a term interchangeably used for pots and pans made from a combination of low fire natural clay, and may contain some additives. The additives are chemicals added to the clay to increase elasticity, for uniformity in firing, and to yield a certain color to the fired items. Chemicals and additives are also added for ease of processing and to increase manufacturing speed. An example of such a chemical is a deflocculant like sodium silicate or Darvan 811 or Darvan 7, these chemicals are added to increase homogeneity and for better suspension and reduce or limit the percentage of water allowing faster drying times. Another example of a chemical added is Iron Oxide, to yield a deep, dark red to the ware. Besides the fact that the raw material could have chemicals, this clay is also not tested and so may contain natural contaminants like mica or contaminants that are present because of careless disposal of industrial waste.
Pure-clay pots and pans: Are pots and pans made from 100% all natural, primary clay. This clay is all natural and is more elastic than earthenware or terracotta because it has two platelets of elasticity between every layer of earth mater. Miriams Earthen Cookware goes one step further to make sure, and let their customers know they only use pure clay by scientifically testing their clay. We are happy to be the only company in the world to do this. This is what makes these pots made from 100% pure-clay the best and healthiest for cooking. Miriams Earthen Cookware pots/pans are pots and pans made using only 100% pure-clay, no other additives or chemicals are used and they’re unglazed.
Being a 100% natural material and used without any mixing/additives, all its nutrients are already bonded together. For this reason it gets fully vitrified at firing temperatures lower than artificial clay like ceramics or porcelain. So firing this ware is much more eco-friendly than the artificial clay.
Since the raw material is pure, glazing it will contaminate the ware and nullify the unique features of cooking with this “breathable” material. So at MEC, we don’t glaze our ware but finish it by applying the same clay on top and burnishing the ware by hand. This is the way cookware used to be made from the beginning, and still is in several very healthy indigenous communities.
Glaze is typically a liquid that is a combination of toxic chemicals, oxides and metallic and non-metallic substances. This list contains some of the ingredients in glazes. It is typically used to cover ware made with ceramic, porcelain, stoneware materials.