According to the Huffington Post, they're both equally effective at heating your food—so just choose whatever side you prefer.
Quite simply, it doesn't matter. Since the exact same material makes up both sides, they will perform precisely the same way. The only difference is aesthetic. So feel free to work both ways.
Reynold's Kitchen, an aluminium foil manufacturer since 1947, says: "It's perfectly fine to place your food on either side so you can decide if you prefer to have the shiny or dull side facing out." It's simply a result of the manufacturing process. The performance of the foil is the same, whichever side you use.
Either side of the foil can be used to place food on, unless you are using Bacofoil® The Non-Stick Kitchen Foil, then the food should be placed on the non shiny side side, as this is the side that is coated with a food safe silicon to stop food from sticking.
"Regardless of the side, both sides do the same job cooking, freezing and storing food," Mike Mazza, marketing director for Reynolds Wrap, told TODAY Home via email. "It makes no difference which side of the foil you use unless you're using Reynolds Wrap Non-Stick Aluminum Foil."
Aluminum foil outperformed tin foil in cost, efficiency, durability, and conductivity, becoming a popular substitute in the following decades. Wartime rations on tin rendered aluminum the standard for packaging, and after World War II aluminum foil completely superseded tin.
Aluminum foil is a thinly rolled sheet of aluminum that's claimed its place as a common kitchen staple. Not only is it safe to cook with aluminum foil in the oven, but cooking with aluminum foil can help transmit heat readily and make cleanup easier.
For safe grilling, use aluminum foil packets or containers as directed. Bottom line: the amount of aluminum that enters food from high-heat cooking is considered safe to eat. If you're trying to avoid excess added chemicals in your diet for any reason, try using lower heat or parchment paper instead.
Food wrapped in foil for the oven should be wrapped with the dull side around the food, it collect the heat.
Q: Why does foil darken or discolor sometimes during baking? A: That discoloration is aluminum oxide, a harmless substance that is naturally present on the surface of the foil. When the foil comes in contact with moisture, it can accelerate the buildup of aluminum oxide.
It is absolutely safe to use aluminum foil in your air fryer. In fact, it can make cooking with the air fryer easier.
The reason the two sides are different is because of the manufacturing process called tilling. However, when it comes to non-stick foil, there is a designated side, which is the dull side, as the non-stick coating is only applied to that side.
It doesn't make any difference which side of the foil you use to wrap hot food or freeze. The two sides are only a result of the manufacturing process.
Place food in the center of the foil and fold up the sides to meet at the top, creating a crease to secure. Leave an inch of space between food and the top of the foil. Place into oven or on the grill until food is warm and ready to serve.
"The recommendation is to avoid cooking things in or on aluminum foil at really high temperatures (400°F or above), and to avoid wrapping acidic foods in aluminum foil for long periods of time," Wegman says.
Aluminum foil can be safely used in a microwave but certain guidelines must be followed to prevent damage to the oven. The following describes the proper use of aluminum foil when microwaving: Aluminum foil is sometimes used to shield portions of a food item to prevent overcooking.
In the United Kingdom and United States it is often informally called "tin foil", just as steel cans are often still called "tin cans".
Tin foil is stiffer than aluminium foil. It tends to give a slight tin taste to food wrapped in it, which is a major reason it has largely been replaced by aluminium and other materials for wrapping food.
It was first produced commercially in the US in 1913 where it was used for wrapping Life Savers™, candy bars and chewing gum. In 1921, it was laminated on paperboard to produce coated folding cartons. Household foil was marketed in the late 1920s, and the first heat-sealable foil was developed in 1938.
The shiny side should be down, facing the food, and the dull side should be up when cooking meals wrapped or covered in aluminum foil since it has a shiny and dull side. This is due to its greater reflectiveness, the shiny side will reflect more heat radiation than the dull side.
Where the foil is in contact with another layer, that's the 'dull' side. The 'shiny' side is the side milled without being in contact with another sheet of metal. The performance of the foil is the same, whichever side you use.
Misconceptions in the Kitchen
In fact, some cooks wrap potatoes in aluminum foil dull side facing out during baking with the belief that the shiny side reflects heat toward the potato, cooking it faster. This is just not so. When baking potatoes, the aluminum foil performs the same -- shiny side facing in or out.