I washed my cooking pot and put some water in it, and put it on the stove.
When the water came close to boiling, I started hearing crackling sounds and there was a thin coat of some substance on the surface.
I thought maybe the pot wasn't clean enough, so I washed it once again thoroughly, but the same thing happened again.
Then I used another pot and everything went fine.
My question is, obviously, what was going on with the first pot, and how do I avoid it?
The obvious theory to me would be that there was still some oil in it, but I did wash it properly and don't even remember putting oil in it recently.
Edit: I'm using electricity to cook (the oldschool 3D round thingie, no glass and no induction) and the pot is made out of stainless steel.
The crackling sounds are not from the pot being wet, they're similar but a bit different (and the pot was dry).
They could be from the pot expanding, but that wouldn't explain the thin layer on the surface of the water.