question about aluminum foil
is there a difference between the shiny side and the non-shiny side of aluminum foil? is one particular side supposed to be in contact with the food or does it not matter?
I think it does not matter unless you are using the non-stick type - in that case the shiny side should face down.
The fact that one side is shinier than the other is an artifact of the manufacturing process. During the last stages of rolling, two layers of foil pass through the rollers together - to reduce the chance of tearing. The side that was in contact with the other piece of foil has a different texture than the outside side.
The shiny side may be a bit more reflective than the other, but probably not enough to make a difference in ordinary home use.
what about the difference between sides of Saran wrap ?
You get a choice... the sticky side that gets stuck on the roll, or the sticky side that sticks to your fingers and everything and folds up and crinkles before you can wrap the food....