I baked meringues for a long time at a low temperature on a tin foil sheet. At first they were fine but then they started forming a sugar-y liquid bottom. When they were finished they all had this gooey-carmel/sugar bottom that totally ruined the meringues. I follow a lot of instructions to make them bake and they had a great texture but I have no idea why they weeped... could it be because I used tin foil instead of parchment paper? any suggestions or advice??