Why do you put aluminum foil on the bone?

To keep it from burning.

Try not to use aluminum foil if you can. Especially when it is heated up. The aluminum leaches into your food. Causing a slow build up of heavy metal toxicity. Which can lead to many adverse health side effects too.

I don't eat the bone.

I am just saying in general stop using it all together if you can. Just looking out for you and your family's health. I read some health studies awhile back and learned how much aluminum leaches into the food. Stopped using it all together and never looked back after that. Now if I am cooking in the oven and I need a liner. I use all natural parchment paper instead. Far superior overall to alumnimum foil and one box of precut sheets helps to cut down on waste too. For cooking on the grill I have not found any substitutions for aluminum foil yet. So I guess it is one of those health over convienance factors for me now.