I’m having a debate with my flatmate…
Which way up does the tin foil go on the baking tray -
Shiny side up or,
Shiny side down?
Or does it even matter?!
Which way up do you place your tin foil?
I place mine shiny side down (just in case you were interested! 
)
According to Cecil Adams, it doesn’t matter.
But does that apply to hats?
To block mind control rays, the shiny side faces out.
Cite.
You’re lining the baking tray with the foil for easy cleanup, I assume? In that case, you should do shiny side down. Shiny side up will reflect slightly more heat back up into the food you’re cooking, increasing the chance of burning the bottom.
Although I’m sure in practice it’s such a small difference it doesn’t really matter.
You’re not making a hat, are you?
Check these folks out. They can help.
Almost never makes a difference. It’s shiny on one side and dull on the other because two sheets are run at once on the manufacturing line, back to back. The side where the sheets touch is the dull side, IIRC.
I can think of one time when Alton Brown specified a side, and that was making his ribs: “Place each slab of baby back ribs on a piece of heavy-duty aluminum foil, shiny side down.” (quote from the Food Network recipe, not the show itself.) In this particular case, I’m almost certain he said it was to slow the radiant heat (only one of the forms of heat an oven puts out) so that the ribs didn’t cook too quickly.
Most of the time, though, even AB says it doesn’t matter.
Well, I have something to add tonight.
My son cooked multiple slabs of ribs tonight. He cooked them using AB’s recipe. He used shiny side down for three slabs. They came out gorgeous browned. He cooked one slab shiny side up. It came out with no hint of any browning.
OK, so what side do zombies prefer?
Brains!
Damn, is it safe to kill a zombie if a fellow mod brought it back from the dead?
Guess we’ll find out.
Apparently not – reopened.
Ooh look, shiny!
Foiled again!
Yeah, I read this one in the *Imponderables *series years ago and the consensus in that book was that you’re ALL right! Every last one of you, no matter what you’re arguing! (Sort of.)
Or, as the book put it: 1) there IS a difference between shiny and dull and 2) the difference is so miniscule that you need laboratory instruments to measure it.
You, or your flatmate, or both, need to find something else to worry about. Like how the other party loads the dishwasher totally wrong.
An intriguing comment, in view of the thread topic!
This is all very boring stuff. I know: let’s hijack this thread into an argumentative, name-calling, frothing-at-the mouth screed about whether it should be aluminum or aluminium foil.
Foil hats aren’t a problem: you just don’t want to get your asshat on upside down.