Ovens and air fryers are just like seasoning cast iron skillets. If you haven’t used this method before, then here is your answer: There’s a layer of oil covering the metal to protect it from forming rust and also provide for ease in cleaning.
When the stove top or oven heats, it evaporates that oil out of the pores of the metal cooking surface over time. The oil leaves a light residue on any food item that gets near it, but if there is too much build up – or if you start scrubbing this coating off – your stove top/oven will rust faster which prevents proper cooking performance when using these appliances. This issue can be remedied by looking up “seasoning an oven” or “seasoning a cast iron skillet,” and it will direct you on what to do.
If you don’t properly maintain these appliances, they’ll rust and pit very quickly. But again, if there is too much build up of seasoning on the metal, scrubbing it off will cause your appliance to become damaged and this step simply isn’t worth it for everyday cleaning purposes.
For more information on how to clean air fryer, read our article: