I have a pizza stone and I have a problem with burned dough sticking to it. So I tried to use aluminum foil on the stone for easy cleanup. I wrapped the stone as tightly as I could with the foil and then used it according to the instructions.
The foil ruined the pizzas, instead of getting a burned crispy bottom I got uncooked dough on the bottom with the top cooked. I first thought that this was because the foil wasn't perfectly tight and the air cushion between the stone and foil acted as an insulator. So I removed the wrapped foil, and used instead a loose sheet of foil to allow the air to escape. But this didn't help. When I then removed the foil entirely and used parchment paper instead everything worked fine (a loose sheet of parchment, like the loose sheet of foil from the 2nd attempt).
Why does the foil ruin the effect of the pizza stone, but works excellent in a press toaster?