i tested mine esbit stove today for the first time and tryed to boil water on top of the stove in a aluminium mess tin. the underside blacked a bit, not very suprising, but what i saw on the other side was some brown staining, wenn i wiped it off with a tissue ( after emtying the tin) and got some black stuff on it.
what is that black stuff ? and are there any health conserns with that brown/black stuff ?