Using a non-stick cooking spray on a cast iron skillet can have a few consequences, and it is generally not recommended. Here's why:
Residue buildup: Non-stick cooking sprays often contain additives like lecithin or propellants that can leave a sticky residue on the surface of the cast iron pan. This residue can build up over time and create a layer that interferes with the natural non-stick properties of the pan. It can also be challenging to remove and may require extra cleaning efforts.
Polymerization issues: Cast iron pans develop a natural non-stick coating through the process of seasoning. This seasoning involves repeatedly applying oil and heating it, allowing it to polymerize and create a smooth, non-stick surface. When non-stick cooking sprays are used, they can interfere with this process and prevent the oil from polymerizing properly. As a result, the pan may not develop a robust and durable non-stick coating.
Residue burning and smoking: Non-stick cooking sprays have a low smoke point, and when exposed to high heat, they can start to burn and smoke. Cast iron skillets are often used for high-temperature cooking methods like searing or frying, and using a non-stick cooking spray can lead to excessive smoking, unpleasant odors, and potentially affect the flavor of your food.
Difficulty in maintaining seasoning: Seasoning is a critical aspect of cast iron maintenance. It helps protect the pan from rust and creates a natural non-stick surface. Using non-stick cooking sprays can create a barrier on the surface of the pan, making it challenging to maintain and build up a proper seasoning. This can result in a less effective non-stick surface and require more frequent re-seasoning.
Instead of using non-stick cooking spray, it is recommended to use other methods for greasing or oiling your cast iron skillet. You can use a small amount of cooking oil or solid fats like butter or lard, which are more compatible with the seasoning process. Applying the oil with a brush or using a paper towel to distribute a thin layer evenly on the surface is preferable.
By avoiding non-stick cooking sprays, you can help maintain the integrity of the seasoning on your cast iron skillet and ensure its optimal performance and longevity.