Microwaving leftover takeout is a quick and easy way to reheat your food. But is it safe to microwave meals still in their original aluminum containers? What happens if aluminum foil touches the sides of your microwave? Let’s take a closer look at whether you can safely microwave aluminum takeout containers.
Here’s a quick answer: Yes, you can microwave aluminum takeout containers, but with care. Use only shallow containers no more than 3cm deep. Ensure food fully covers the bottom and heat just 1 container at a time, for only 1-2 minutes. Stop immediately if arcing sparks occur. For best results, transfer food to microwave-safe dishware.
The Lowdown on Aluminum Foil in Microwaves
Aluminum foil and aluminum takeout containers interact differently with microwave radiation compared to microwave-safe materials like glass or ceramic.
When microwaves hit aluminum, they cannot penetrate the material and instead bounce off it. This reflective property makes aluminum great for shielding foods you don’t want heated. But it also means food in aluminum containers will not heat evenly throughout.
The food touching the foil may overheat while the top remains cold. In extreme cases, arcing can occur if foil is too close to the oven walls. This is when electricity jumps from the aluminum to the walls, causing sparks and potential damage.
So is it really safe to microwave that leftover Chinese takeout still in the tin tray?
Are Aluminum Takeout Containers Microwave-Safe?
The good news is aluminum takeout containers are generally safe to microwave, with a few precautions:
- Use only shallow containers, no more than 3 cm deep. This allows microwaves to better penetrate food.
- Make sure food fully covers the bottom of the container. No bare spots of foil should be exposed.
- Place the container directly on a microwave-safe dish. Do not let foil touch or arc to oven walls.
- Remove any aluminum lids prior to heating. Use microwave-safe plastic lids or cover with a paper towel.
- Heat only 1 container at a time. More can lead to arcing.
- Keep heating time short, around 1-2 minutes at a time. Then stir/rotate food and heat again if needed.
- Stop immediately if you see sparks! This means arcing has occurred.
As long as you follow these guidelines, aluminum takeout containers are generally safe for quick reheating. The FDA also considers them microwave-safe. But for optimal results, it’s best to transfer food to microwave-safe dishware.
Glass, ceramic, and microwave-safe plastic containers will heat food far more evenly than aluminum. Food also tends to stick less to these non-porous materials.
If transferring food isn’t an option, try these microwave-safe alternatives next time you order takeout:
- Paper cartons or boxes
- Waxed paper or cardboard containers
- Microwave-safe plastic tubs or trays
- Foam trays covered with plastic film
With the proper precautions, microwave ovens will not arc or spark when using aluminum foil containers. But for best results, microwave-safe containers are recommended whenever possible.
Microwaving Different Types of Aluminum Containers
Not all aluminum containers are created equal when it comes to microwave safety. Thickness, shape, and contact with food can impact heating. Let’s look at some common types of takeout containers and their microwaveability:
Aluminum Foil Takeout Trays
Foil takeout trays are thin and mold easily to food contents. The shiny side should face up when microwaving to better reflect heat down into food. Avoid overfilling trays which can cause food to touch sides.
With proper precautions, these single-use trays are microwave-safe for brief 1-2 minute intervals. Discard after use.
Aluminum Takeout Tins
The tins used for Chinese takeout and doggy bags are thicker aluminum and more rigid. They are safe for brief microwave heating using the tips above. But the thicker metal leads to uneven hot spots. Transferring food to a microwave-safe dish gives better results.
Aluminum Pizza Pans
Some pizza joints place your piping hot pizza into an aluminum pizza pan or dish when you order for delivery or takeout. The thicker metal and shallow depth make these pans microwave-safe using care to prevent arcing. Remove any metal rack or surface the pizza sits on prior to heating.
Pie Plates or Bread Loaf Pans
Restaurants sometimes package items like pies, breads, and cakes to-go in aluminum pie plates or loaf tins. These should not be microwaved with items inside. The deep sides and enclosed metal interior make arcing and sparks far more likely. Always transfer food to microwave-safe dishware first.
Aluminum Sauce Cups
Many takeout places provide small aluminum sauce cups for dipping sauces, dressings, etc. Never microwave these! The small metal containers can easily arc and damage your microwave. Always transfer sauces or condiments to microwave-safe bowls or ceramic mugs before heating.
Never microwave food with an aluminum foil lid in place. Always remove lids prior to heating. Foil lids can easily spark and damage microwave interiors. Replace with a paper towel or microwave-safe plastic wrap instead.
By understanding the risks of various aluminum containers, you can make informed decisions about how to best reheat your takeout meals. When in doubt, transfer to microwave-safe dishware.
Tips for Safely Reheating Leftovers in Aluminum Containers
Follow these tips every time you go to reheat takeout leftovers in their original aluminum containers:
- Inspect for damage – Do not use foil containers that are severely dented, warped, or punctured. Damaged areas concentrate microwaves.
- Half power – Heat food at 50% power in 1-2 minute intervals to prevent hot spots and arcing.
- Loosely cover – Use paper towels or microwave-safe lids instead of aluminum foil. Leave a vent for steam to escape.
- Rotate container – Turn the dish every 30 seconds to help food heat evenly.
- Stir food – This helps distribute heat and prevent overly hot areas near the foil.
- Check temperature – Stir and let food sit 1-2 minutes before consuming to allow heat to fully distribute.
- Stop immediately if arcing – You’ll see sparks if foil gets too close to oven sides.
Following these simple steps will ensure you safely reheat leftovers with minimal risk when using aluminum containers.
Can You Microwave Aluminum Foil?
While aluminum takeout containers are designed to be microwave-safe, what about using household aluminum foil in the microwave?
It’s not recommended, but very short heating times can allow you to safely use aluminum foil in a pinch. Here are some guidelines:
✔️ To cover bowls – Use a small 4-6 inch square of foil to cover food. Make sure foil is flat, smooth, and not near oven walls. Keep heating to under 1 minute.
✔️ As a shield – Use a foil shield to prevent parts of food from overcooking. Shield thin areas like fish tails or chicken wings.
❌ Never line oven floors/walls – This can cause arcing and damage the microwave.
❌ Don’t make foil pouches – Enclosed foil pouches hold in steam which can burst and damage the oven.
❌ Don’t use crumpled foil – Wrinkles and creases concentrate microwaves and are prone to arcing.
For optimal microwave cooking, plastic wrap, wax paper, parchment paper or paper towels give the best results. Reserve foil for quick heating jobs or shielding delicate spots.
Signs of Arcing and How to Prevent It
Arcing refers to the moment when electricity jumps from your aluminum container to the microwave walls because they’ve gotten too close. This causes visible sparks and can damage your microwave.
Arcing can occur when:
- Foil is too close to oven sides
- Two pieces of foil touch
- Foil has sharp points or edges
- Foil is wrinkled or crumpled
- Food contents are very fatty, sugary, or moist
You’ll know arcing has happened if you:
- See visible sparks inside the oven
- Hear crackling or popping sounds
- Notice burn marks on interior walls
- See damage to turntable surface
To prevent arcing:
- Keep foil at least 1 inch from walls
- Smooth all wrinkles from foil
- Microwave only 1 foil item at a time
- Stop cooking immediately if arcing occurs
With extra care, you can avoid shorts and sparks when reheating food in aluminum containers. Place foil directly in the center of the turntable, away from sides. Stop cooking immediately at any sign of arcing to prevent damage.
Is It Bad to Microwave Aluminum Foil?
While careful microwave use won’t damage your oven or foil containers, there are some downsides:
- Uneven heating – Food in foil will have significant hot and cold spots.
- Food sticking – Food can stick to foil, making for a messier clean up.
- Heating limits – You must use lower power and shorter cook times to prevent arcing.
- Not eco-friendly – Foil containers create more waste compared to reusables.
- May leach aluminum – Trace amounts of aluminum can leach into acidic or salty foods.
For these reasons, microwave-safe containers provide optimal heating. Glass, ceramic, and some plastic containers won’t suffer from uneven hot spots the way foil does.
Transferring food from foil to microwave-safe dishware gives you way more flexibility and control over cooking times and temperatures.
Is Reheating Food in Aluminum Containers Dangerous?
There is no evidence that briefly reheating food in aluminum foil trays or tins poses any significant health risks. However, regular and prolonged use is not recommended, mainly due to risks of uneven cooking.
Here are a few health concerns surrounding aluminum usage:
- Aluminum leaching – Acidic foods like tomato sauce can cause small amounts of aluminum to migrate into food when heated in foil.
- Food overheating – Hot spots in foil can potentially overheat parts of your food above safe eating temperatures. Always check temperatures before consuming.
- Alzheimer’s myths – Despite rumors, cooking with aluminum does not cause or increase your risk for Alzheimer’s disease according to leading health organizations.
To enjoy your leftovers safely, be sure to follow reheating guidelines and never microwave any aluminum container for more than 2-3 minutes. Transferring food to glass or ceramic dishware is ideal when possible.
FAQ About Microwaving Aluminum Takeout Containers
Still have questions about the safety of reheating your takeout in aluminum trays or tins? Here are answers to some frequently asked questions:
Can aluminum foil go in the microwave?
Yes, for very brief cooking times. Use smooth, flat sheets and avoid the foil touching sides. Never use wrinkled foil or make fully enclosed pouches.
Do restaurants use microwave-safe aluminum containers?
Most commercial aluminum containers are designed to be microwave-safe for short term use. But they still have hot spots, so microwave with care.
What if I see sparks in my microwave when using aluminum?
Stop cooking immediately! Sparks mean dangerous arcing has occurred. Do not run the microwave again until having it inspected for internal damage.
Is it safe to reheat pasta or rice in foil?
Pasta and rice are very prone to drying out and overheating in foil containers. For best results, transfer them to microwave-safe bowls before reheating.
Can I reheat a whole frozen meal in an aluminum tray?
No, you should always break up frozen meals into smaller sections when reheating in foil trays. Microwave single servings for 1-2 minutes at a time.
What about reheating pizza in the aluminum pan?
As long as the pan is shallow (1 inch deep or less), it is generally safe to briefly reheat leftover pizza still on its aluminum pizza pan. Use care not to let metal edges arc.
How do I prevent food from sticking to aluminum when reheating?
Lightly coat or spray foil interiors with nonstick cooking spray prior to reheating food. This prevents sticking.
While it’s best to transfer food out of foil takeout containers before reheating, brief 1-3 minute bursts in the microwave pose low risk when precautions are used. Never microwave any aluminum for long cook times, and stop immediately if arcing occurs.
Shallow, smooth aluminum foil trays and tins can be microwaved safely in small doses. Just beware of hot spots, prevent arcing to oven walls, and use lower power levels. With extra care and proper use, aluminum takeout containers give you a quick and convenient way to reheat leftover meals.