Non-coated cast iron is easy to rust, but when it is reheated over 900degrees(1652F), an iron oxide film (Fe3O4) is naturally formed on the surface and therefore enables the surface to be rust free.
Traditional Japanese “Nanbu” iron kettles are manufactured using a similar process. By manufacturing the kettles in a charcoal fire this artistic technique prevents rust forming inside the kettles.
Developing the Naked Pan, Oigen has reformed a traditional crafts technique with the use of modern technology to create an oxide film which is strong yet protective and in the same process obtain a manufacturing patent.
Additionally Oigen has been able to ensure that no form of chemical substance leeches during high temperature cooking, therefore giving confidence that organic food retains its true flavours.