Aluminum foil is endlessly versatile. You can use it to wrap up leftovers, cover a bowl that needs to be stashed in the fridge for a bit, line a baking sheet, clean a pan, and more. You know this. That’s why you, most likely, have a box or three in your home right now. While foil is a great thing to keep around, there are a few things you shouldn’t do with it.

There are a few questionable uses for foil (namely, some people worry about cooking food in foil), but this story is about things you should definitely never do. Here are five things to skip when it comes to your roll of aluminum foil.


1. Don’t put it in the microwave.
This one’s probably the most obvious, but a little reminder can’t hurt — never, under any circumstances, put anything with foil on it in the microwave. Unlike paper or glass, electromagnetic waves can’t pass through metal, so they bounce off — which could result in sparks and flames that could damage your oven or, worse, start fires.

2. Don’t bake cookies on it.
While you can use foil to line a baking sheet for, say, crisping up bacon in the oven, it’s not the best liner for your sheet if you’re making cookies. Lining your cookie sheet with aluminum foil can cause the bottom of your cookies to cook faster, ultimately resulting in uneven bake. Instead, use parchment paper, a silicone baking mat, or a really good nonstick spray.

3. Don’t line the bottom of your oven with it.
In theory, lining the bottom of your oven with aluminum foil as a catch-all for pesky drips and spills is a good idea. In practice, it’s not. Even the folks at Reynolds Wrap say it’s a bad idea: “To avoid possible heat damage to your oven, we do not recommend using aluminum foil to line the bottom of your oven.” Instead, Reynolds says to use a piece of their Heavy Duty foil on the oven rack below whatever you’re baking. (Pull off a length that’s a little longer than the pan you’re using.) This will allow for proper heart circulation and catch any drips.

4. Don’t use it for acidic foods.
Acidic foods (like tomatoes, tomato sauce, and tart fruits) can interact with the aluminum and, after a few days, erode the foil. For these foods, you’re better off using plastic wrap or or even glass containers. Also: If you’re wrapping food up with foil, it’s best for a temporary solution, as a foil-wrapped burrito is not airtight.


5. Don’t toss it after one use.
Aluminum foil can totally be reused if it’s clean enough and not too crumpled. (You can even hand-wash it or put it in the dishwasher on the top rack.) Why not get some extra milage out of the stuff? Also, aluminum foil can almost always be recycled. Check with your town or recycling provider and then do your par