CAST IRON

Cast iron is not a metal, but an alloy composed of iron (Fe) and carbon (C) in high percentages (between 2.11% and 6.67%, which is the maximum limit of solubility of carbon in iron).

Cast iron, compared to iron, has higher mechanical strength, a higher specific heat capacity and lower thermal conductivity. Therefore, it is able to maintain higher and more stable cooking temperatures than iron. In some cases, these temperatures are too high for certain types of cooking. For this reason, iron is preferred for delicate cooking, while cast iron is widely used in the production of hobs and griddles.

From a chemical point of view, it presents the same problems as iron and is subjected to the same treatment.

Traditionally, to avoid rapid oxidation, iron items designed for cooking go through a curing process. This involves covering the entire surface of the receptacle (both inside and outside) with a layer of grease or oil and subjecting it to a high-temperature process, creating a protective layer that will penetrate the pores, making it impermeable when hot, and will polymerize, forming a non-stick layer similar to the latest polymer coatings.

Over time, a stable black oxide is created beneath the polymerized layer that has excellent protective properties. However, during the initial period of use, it is a good idea to treat the ferrous receptacle carefully as the polymer layer is quite delicate. The use of metal or abrasive sponges and aggressive detergents should be avoided.

Maintenance

Fine salt is used for cleaning. Until the interior becomes blackened, it is advisable to oil it frequently and avoid cooking acidic foods. Particularly in the past, the inside of iron pans was often enamelled. However, these enamel layers are not very resistant to wear or sudden changes in temperature and tend to deteriorate over time.

Aluminium

ALUMINIUM IS A CHEMICAL ELEMENT WITH THE SYMBOL AI, WHICH IS VERY ABUNDANT IN THE EARTH’S CRUST, CONSTITUTING 7.3% OF ITS MASS.

IT IS A VERY SOFT, MALLEABLE, NON-MAGNETIC METAL WITH A VERY GOOD THERMAL CONDUCTIVITY. IT IS THE CHEAPEST AND THE LIGHTEST OF THE METALS USED FOR THE MANUFACTURE OF KITCHEN UTENSILS. IN CONTACT WITH AIR, A THIN LAYER OF OXIDE FORMS, WHICH ADHERES VERY WELL TO THE METAL AND IS EQUIPPED WITH EXCELLENT ANTI-STICK PROPERTIES. THE DOWNSIDE IS THAT THIS PATINA IS VERY THIN AND CAN BE EASILY SCRATCHED. TO OBTAIN A THICKER OXIDE LAYER, SOMETIMES ALUMINIUM IS SUBJECT TO THE ANODIZATION PROCESS.

Did you know that?

Due to its low density, its specific heat capacity is lower than that of other metals, so a thicker base is required to maintain stable cooking temperatures. In addition, aluminium, especially where it is thin, can easily harden.