Build a solar oven by cutting a flap in the attached lid of a corrugated cardboard box. Attach foil inside the box to reflect the heat. Cover both sides of the opening from the flap with plastic wrap to form a window.
- Select the right box
Choose a sturdy box that is large enough to hold the cooking container. It should have an attached lid.
- Cut the oven door
Mark a line 1 inch from three edges of the box lid. Use a box cutter to cut along the line, leaving the flap attached at the back of the box.
- Cover the inside with foil
Use glue to attach aluminum foil to the inside of the box. Cover the inside of the cardboard flap with foil. Keep the foil as free of wrinkles as possible so it forms a mirror-like surface.
- Create a window
Use tape to attach plastic wrap to both sides of the opening surrounding the flap.
- Test the oven
Lift the box lid to place the food inside the oven. Close the lid. Turn the oven so the sun reflects from the flap through the window onto the food. Use a stick to prop the flap in position. Adjust the position of the oven and flap as the sun moves while cooking. Once the food is ready, open the lid and use oven mitts to remove it from the oven.