Have you ever thought about why the two sides have different finishes?


Every cook has his or her favorite tools and appliances, and many swear by high-end brands for their beloved cast iron skillets and casserole dishes. But one of the cheapest kitchen accessories all cooks agree on? Aluminum foil. We'd be remiss if we didn't acknowledge it as one of the hardest working tools in our arsenal.

And if you use aluminum foil as often as we do, you have probably noticed that one side of the foil is shinier than the other. Maybe you see the shiny side as the "right" or "top" one and always have it facing up. Or, if you're often writing labels or cooking instructions on aluminum-foil-covered baking dishes, perhaps you prefer the duller side for that. Have you ever thought about why the two sides have different finishes, though?

Luckily, Reynolds Wrap is letting us in on their little secret. As it turns out, the different appearances of each side of aluminum foil are simply a result of how it's manufactured. There's no coating or anything, and as Reynolds Wrap points out, the performance of the foil is the same on both sides. In the factory, the sheets of foil are produced using a process called milling, which heats and stretches the aluminum into the thin layers we buy in store.

According to the Reynolds Kitchens website: "We mill two layers in contact with each other at the same time, because if we didn't, the foil would break during the milling process. 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."

Well there you have it. Should it ever come up, you can cleverly settle any disagreement over which side is the right one to use. If only every cooking debate were solved so easily.

Comments (1)

October 10, 2019
I have always taught my cooks to put the shiny side towards the food to reflect the heat inwards. Plus, the dull side is easier to view writing on when you are labeling with a sharpie.