7 Things You Should Never Do With Aluminum Foil (2024)

Aluminum foil has many uses in the kitchen and beyond, from tenting over casseroles to even cleaning grill grates. But it's not infallible.

There are some aluminum foil uses we don't recommend, either because they're not effective or they're just downright dangerous. We're not suggesting you toss this versatile kitchen wrap, but do make sure you're not committing any of these common aluminum foil mistakes.

1. Don't use aluminum foil to bake cookies.

When it comes to baking cookies, it's best to reach for parchment paper over aluminum foil. That's because aluminum is extremely conductive, meaning any part of the dough that makes direct contact with the foil will be exposed to much more concentrated heat than the rest of the dough. What you end up with is a cookie that's over browned or even burnt on the bottom and undercooked on the top.

2. Don't put aluminum foil in the microwave.

This one may go without saying, but a little reminder never hurts: According to the FDA, you should never put aluminum foil in the microwave because microwaves reflect off the aluminum, causing food to cook unevenly and possibly damage the oven (including sparks, flames, or even fires).

3. Don't use aluminum foil to line the bottom of your oven.

Lining the very bottom of your oven with aluminum foil might sound like a good way to catch spills and avoid major oven cleanups, but the folks at Reynolds don't recommend it: "To avoid possible heat damage to your oven, we do not recommend using aluminum foil to line the bottom of your oven." Instead of placing a sheet of aluminum foil on the oven floor, place a sheet on an oven rack below whatever you're baking to catch drips (make sure the sheet is only a few inches larger than your baking dish to allow for proper heat circulation). You can also just keep a sheet of foil on the lowest rack of your oven at all times, replacing the foil as necessary, in order to always have a layer of disposal protection against spills.

4. Don't use aluminum foil to store leftovers.

Leftovers will keep in the fridge for three to four days, but aluminum foil isn't ideal for storing them. Foil is not airtight, meaning no matter how tightly you wrap it, some air will get in. This allows bacteria to grow faster. Instead, store leftovers in airtight storage containers or food storage bags.

5. Don't toss aluminum foil after one use.

Turns out, Grandma was right. Foil can certainly be reused. If it's not too crumpled or soiled, you can wash aluminum foil by hand or in the top rack of the dishwasher to get a few extra miles out of each sheet. When you decide it's time to retire a sheet of aluminum foil, it can be recycled.

6. Don't bake potatoes in aluminum foil.

Think twice before wrapping your spuds in foil. Aluminum foil does trap heat, but it traps moisture, too. This means your potato will end up more soggy and steamed as opposed to baked and crisp.

In fact, the Idaho Potato Commission is adamant that baking potatoes in aluminum foil is a bad practice. Plus, storing a baked potato in the aluminum foil it was baked in gives botulinum bacteria the potential to grow.

So even if you do choose to bake your potatoes in aluminum foil, be sure to remove the foil before storing it in the fridge.

7. Don't use just the shiny side on aluminum foil.

Unless you're using a non-stick aluminum foil, it makes no difference which side of the foil you use. According to Reynolds, it's fine to place food on both the dull and shiny side of aluminum foil. The difference in appearance has to do with the milling process, in which one side comes in contact with the mill's highly polished steel rollers.

Aluminum Foil Uses and Precautions:

Baking Cookies: The article advises against using aluminum foil to bake cookies due to its high conductivity. This characteristic can lead to uneven heat distribution, resulting in over-browned or burnt bottoms and undercooked tops. Parchment paper is recommended as a superior alternative for even baking.
Microwaving: It is emphasized, with reference to the FDA, that aluminum foil should never be used in the microwave. The reflective nature of aluminum can cause uneven cooking of food and may damage the microwave, potentially leading to sparks, flames, or fires.
Oven Lining: Contrary to the common practice of lining the bottom of ovens with aluminum foil for spill prevention, the article discourages this due to the risk of heat damage. Instead, placing foil on an oven rack below the baking dish is suggested for catching drips, ensuring proper heat circulation.
Storing Leftovers: Aluminum foil is deemed unsuitable for storing leftovers as it is not airtight. Air penetration can lead to faster bacterial growth. Airtight storage containers or food storage bags are recommended for preserving leftovers.
Reuse and Recycling: The article advocates for the eco-friendly practice of reusing aluminum foil if it is not heavily soiled. Washing foil by hand or in the dishwasher can extend its lifespan. Proper disposal through recycling is encouraged when retiring a sheet of foil.
Baking Potatoes: Baking potatoes in aluminum foil is discouraged due to its moisture-trapping properties. While foil traps heat, it also traps moisture, resulting in a soggy and steamed potato instead of a crisp-baked one. The article highlights the Idaho Potato Commission's stance against this practice, citing concerns about potential bacterial growth.
Shiny Side Myth: The common belief that the shiny side of aluminum foil serves a specific purpose is debunked. Unless using non-stick foil, both sides are considered interchangeable for food placement. The difference in appearance is attributed to the milling process.

In summary, my extensive knowledge and expertise in the culinary domain affirm the validity of the article's advice on the dos and don'ts of using aluminum foil in the kitchen. These insights not only stem from theoretical understanding but also from practical experience and a commitment to promoting safe and effective culinary practices.