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The Great Aluminum Foil Debate: Shiny Side Up or Down?

Which side of aluminum foil are you supposed to use? We called in the experts to find out.

Whether you’re roasting bell peppers, oven-steaming fish, or baking a batch of blondies, you need a trusty roll of aluminum foil to help you get the job done. So many recipes call for foil that you may not even think twice about it as you dash off yet another sling for your pan—but we wondered if there’s a right and wrong way to use it. Foil has a shiny side and a dull side, and we tend to use the two sides interchangeably in the kitchen: But what if one side is better than the other? 

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To get some answers, we reached out to Reynolds Consumer Products. A representative of the company told us that foil’s shiny- and dull-sidedness is simply the result of the manufacturing process—and that there are no performance differences between the two sides. The only exception? If you’re using a nonstick foil, which may only be nonstick on one side.

But of course, we wanted to test this out for ourselves. We conducted three experiments, each designed to prove or disprove the negligibility between foil’s two sides. Here’s what we found out.

The Potato Test

THE EXPERIMENT: We baked two potatoes, each of exactly the same weight, in a 350-degree oven, one wrapped in foil with the shiny side facing out and the other with the shiny side facing in.

THE RESULT: After one hour, both potatoes reached an internal temperature of 198 degrees.

The Water Test

THE EXPERIMENT: We filled two ovensafe beakers with 71-degree water and wrapped each in foil, one, shiny side out, the other, shiny side in.

THE RESULT: After 30 minutes in a 350-degree oven, the water in the beaker wrapped in foil with the shiny side in was 2 degrees hotter.

The Leftovers Test

THE EXPERIMENT: We baked cold mashed potatoes in two eight-by-eight glass baking pans covered in foil, one with shiny side out, the other, shiny side in.

THE RESULT: After 45 minutes, the pan with the shiny side facing in was 2 degrees hotter.

With that, we felt confident concluding that it’s true that the two sides of foil are pretty much interchangeable. Which is great news: Less time thinking about which side of the foil to use means more time to decide what to cook in it

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JC
JOHN C.
16 days

Absolutely the best chicken ever, even the breast meat was moist! It's the only way I'll cook a whole chicken again. Simple, easy, quick, no mess - perfect every time. I've used both stainless steel and cast iron pans. great and easy technique for “roasted” chicken. I will say there were no pan juices, just fat in the skillet. Will add to the recipe rotation. Good for family and company dinners too. I've done this using a rimmed sheet pan instead of a skillet and put veggies and potatoes around the chicken for a one-pan meal. Broccoli gets nicely browned and yummy!

Absolutely the best chicken ever, even the breast meat was moist! It's the only way I'll cook a whole chicken again. Simple, easy, quick, no mess - perfect every time. I've used both stainless steel and cast iron pans. great and easy technique for “roasted” chicken. I will say there were no pan juices, just fat in the skillet. Will add to the recipe rotation. Good for family and company dinners too.

MD
MILES D.
JOHN C.
9 days

Amazed this recipe works out as well as it does. Would not have thought that the amount of time under the broiler would have produced a very juicy and favorable chicken with a very crispy crust. Used my 12" Lodge Cast Iron skillet (which can withstand 1000 degree temps to respond to those who wondered if it would work) and it turned out great. A "make again" as my family rates things. This is a great recipe, and I will definitely make it again. My butcher gladly butterflied the chicken for me, therefore I found it to be a fast and easy prep. I used my cast iron skillet- marvellous!

CM
CHARLES M.
11 days

John, wasn't it just amazing chicken? So much better than your typical oven baked chicken and on par if not better than gas or even charcoal grilled. It gets that smokey charcoal tasted and overnight koshering definitely helps, something I do when time permits. First-time I've pierced a whole chicken minus the times I make jerk chicken on the grill. Yup, the cast iron was not an issue.