Cooking & Baking

Barkeepers Friend or some other polish will usually work to get some shine back, but aluminum is soft and reactive so a patina is kind of unavoidable, especially if you just chuck them in the dishwasher like I do. All of mine are matte grey and a bit splotchy, but they still cook fine.

As for the warping, make sure you're buying 1-inch deep sheet pans, not flat cookie sheets, and that they have a wire rim (it should say on the packaging or listing); they need a little structure to not flex when they get hot,

Hope this helps, cheers