According to reynold's kitchen, the difference in appearance between the two sides of aluminum foil is simply a result of manufacturing and serves no real purpose.
New Aluminum Foil Shiny Side Up Or Down
Pics. After all, one side of the foil is matte and the other side is shiny. Foil insulation underlayment is recommended under a metal roof, and in most cases, the shiny side should be facing up, but there's a catch.
40 Genius Uses For Aluminum Foil from sbly-web-prod-shareably.netdna-ssl.com
Matte is the opposite of shiny or glossy. One of aluminum, another that is coating. This is because the shiny side is more reflective and so will reflect more of the radiant heat than the duller side.
This is because the shiny side is more reflective and so will reflect more of the radiant heat than the duller side.
You may have suspected that there is a hidden feature to your aluminum foil as well. If the surface really gets to the same temperature. Since aluminum foil has a shiny side and a dull side, many cooking resources say that when cooking foods wrapped or covered with aluminum foil, the shiny side should be down, facing the food, and the dull side up. If you're baking or defrosting, the matte side will absorb more radiant heat and reflect less infrared heat while the shiny side will reflect more of both, so it makes more sense to bake and defrost with the matte side facing up.
