Aluminum Foil Reaction with Fire Question

[Dana Dickson]

J.K. Childers wrote:
>
> Why does alunimum foil turn yellowish after being in a fire?
> I regularly cook foil meals on campouts and have noticed this
> color change almost every time ...but not always. Is there a
> link to the heat of the fire, or is it a type of foil, type of
> fuel in the fire, or some other condition that causes this
> color change only MOST of the time?
>
> Also, is there any harm to my food when this occurs? I'm not
> really 'concerned', just curious. It could be something as
> simple as smoke accumulation, but whatever it is, it is hard
> to rub off.
>
> If you know the answers, please share your knowledge.
>
> Thanks, J.K. Childers

The yellow is condensed smoke and partly burned fuel.

[J.K. Childers]