I know what the foil manufacturers say (it doesn't matter), but I consistently have much less sticking (roasted vegetables, salmon, etc.) when the dull side is up, (controlling for the same application of olive oil, same temperature, same cooking methods, etc.).

Anonymous wrote:It does not matter which side you wrap against the food or put down on the cooking tray. The shiny and dull sides are a byproduct of the manufacturing process and it wasn’t deliberately designed that way.

+1

It does not matter which side you wrap against the food or put down on the cooking tray. The shiny and dull sides are a byproduct of the manufacturing process and it wasn’t deliberately designed that way.

For some reason I usually put the shiny side against the food, but I don't know why. Just habit I guess. I don't think it matters at all.

Anonymous wrote:No cooking on foil, I am an avid home cook and cook on parchment. It’s foolproof and better for you!

I’m one of the PPs and I was talking about wrapping/covering with foil, not cooking on it.

No cooking on foil, I am an avid home cook and cook on parchment. It’s foolproof and better for you!

If you are trying to preserve heat, shiny side in . . . otherwise, it doesn't much matter.

Anonymous wrote:Shiny side out. I don’t know why. The weirdest thing is that I was just thinking of asking this same question here last night.

Whoa. That is a weird coincidence. Maybe you and OP are long lost identical twins?

Shiny side out. I don’t know why. The weirdest thing is that I was just thinking of asking this same question here last night.

Dull

It does not matter

I don't pay attention. It will depend more on how I'm pulling it out in relation to the food. If I'm pulling it out over food on a surface, whatever side is facing down will be touching the food item. If I'm laying it out flat to put something on top of it, whatever side is facing up will be touching the food. In terms of performance, there is no difference: https://www.finedininglovers.com/article/food-answers-which-side-foil

Great question.

My best guess is that the dull side touches the food. (Hopefully others with actual knowledge on the matter will respond.)

Do you put dull or shiny side facing the food?