I know nothing about anything. But especially woodworking and blacksmithing. Is it to do with the varnish? The wood? Is there a protective layer on top? Is varnish a protective layer and did i just repeat myself? Am I asking too many questions?
We all know wood is flammable, but if you hold a cigarette lighter up to a tree, it won't cause it to go up in flames.
The bigger the wood, the more energy it needs to ignite. Tiny bits of wood, like sawdust, will burn up instantly and easily, but the wood on your pot will only start to turn black from the heat unless you get it up to around 600-700°F.