“Putting on the Foil Coach” | Thermographic Cookery

The age old question of which way to wrap the aluminum foil on your potato (shiny side out or in) before baking it has been answered. It turns out that the answer is “yes”.

It actually does not matter which side of the foil faces out for cooking or freezing food. To understand why, an explanation of what the foil actually does may be of some help. The purpose of applying aluminum foil for cooking is actually to insulate the food to be cooked from the infrared radiation that the appliance or campfire is going to apply to it. The low emissivity and high reflectivity of the aluminum foil makes it an ideal insulator to keep from cooking your potato too fast and burning it or drying out.

When cooking in an oven or barbecue the thermal mediums present are hot air and infrared radiation. The infrared radiation is projected outward and in all directions from the heat source: burner plates, heating elements or charcoals. Air is heated as it comes into contact with the heat source, which then rises to encircle the food or it is forced around the inside of the cooking enclosure by a fan, like in a convection oven.

The foil acts like a mirror to the infrared radiation. Picture a mirror bouncing Superman’s laser vision away from its target, which means the food will be mainly cooked with the hot air that encircles it. This helps to slow down the cooking process to keep from burning or drying out your baked potato.

You could say that the foil helps to keep the “radiation” in your oven from burning your potato. It is still up for debate; however, if the foil hat you where keeps the Men in Black helicopters from cooking your melon. 😉