Introduction
While microwaves are a magnificent invention and a staple of every kitchen, they can’t do everything. Asking if you can microwave cardboard is a great question and one we will answer in the following article among a plethora of other related questions.
If you’d like to skip to any of the sections in this article, you can click the links below, otherwise continue reading into the first section to know whether you can microwave cardboard.
Click the links below to skip to the section:
- Can You Microwave Cardboard
- Can You Microwave Cardboard Takeout Boxes
- Can You Microwave a Cardboard Pizza Box
- What is the Best Way to Microwave Food
- Tips for Using the Microwave
Can You Microwave Cardboard?
The quick answer is generally no, you cannot and should not microwave cardboard. There are a few reasons and also a few exceptions that we’ll talk about now.
There are some types of cardboard that are microwave safe, however not all cardboard is safe for the microwave so generally it’s better to err on the side of caution and avoid putting something that is potentially dangerous into the microwave.
Some cardboard containers contain glue or other chemicals to bind the cardboard together in a specific shape. There also other chemicals like the marker or text that can bleed into your food, which is not safe for human consumption. As a result, it’s generally safer to avoid microwaving any cardboard than taking chances on some cardboard being safe and others not.
With that said, it’s important to note that some cardboard is safe to microwave and we’re not saying your microwave will explode or start a fire if you microwave a small piece of cardboard. We just prefer to err on the side of caution and avoid any potential damage to the microwave or our bodies.
Can You Microwave Cardboard Takeout Boxes?
While the previous section was just a general recommendation regarding all types of cardboard, in this next section we’ll discuss takeout boxes.
Now, takeout boxes are a little different because most restaurants understand that you’ll probably want to microwave your leftovers the next day, so most restaurants will choose microwave safe takeout containers for your leftovers. However that’s not always the case.
In this scenario, it’s best to be diligent in your decision whether or not to microwave cardboard takeout boxes. Sometimes you can microwave takeout boxes and other times you shouldn’t.
For example, if you’re thinking of microwaving Chinese leftovers and they’ve given you the food in a classic Chinese takeout container with the metal handle, then do not microwave that. Metal cannot be microwaved under any conditions.
However, if the Chinese takeout container doesn’t have the metal handle and it’s just the box, then you should be okay to microwave that.
If you want to be super safe, you can ask the restaurant when they give you your leftovers whether their takeout containers can be microwaved. They should let you know whether or not it’s safe to microwave.
Can You Microwave a Cardboard Pizza Box?
Another common question is whether or not cardboard pizza boxes can be microwaved and in this case, we would not recommend microwaving the cardboard pizza box. And we recommend this for a couple reasons.
First, there are better ways to reheat pizza. We’ve actually written about this in another blog post discussing whether or not you can put a pizza box in the oven. The quick answer is no, but that article also contains a lot of great ways on how to reheat your pizza, including a few pizza related tools for your kitchen. If you haven’t read it already, we recommend doing so.
The second reason is that a cardboard pizza box is unlikely to even fit in the microwave. And you don’t want to cut the pizza box into smaller pieces in the event that it’s held together with glue or releases other cardboard related chemicals into your food, such as the text coloring.
Similar to takeout boxes, there are exceptions to this. Some pizza restaurants provide their takeout or to-go pizza in a container specifically meant for a microwave. It usually contains what looks like dull tinfoil on the inside, which is meant to reflect the heat in the microwave onto the pizza. However, and we’ll cover this later in the article, do not under any circumstances put tinfoil in your microwave. It can cause damage and likely start a fire.
If your to-go or leftover pizza came in a container like this, it’s probably okay to microwave and will likely say so on the counter.
But if you’re thinking of cutting up the box that the pizza came in and microwaving it from there, you shouldn’t. At the very least, wouldn’t it be easier to just throw the pizza on a plate?
What is the Best Way to Microwave Food?
Now that you know generally not to microwave cardboard, you might be wondering what is the best way to microwave food. And to answer that, we’ll have to talk a little about how microwaves work.
How Microwaves Work
Have you ever wondered why when you microwave a food item, the outside is hot as a volcano, but the inside can be as cold as the back of your freezer? That’s because of how microwaves heat up items.
No surprise here, but microwaves use microwaves to heat up the food. Aptly named, right? Well those microwaves emanate from the sides of the microwave in a defined direction. That’s why microwaves usually have a spinning plate because otherwise only one part of your food would get cooked, while the rest remains mostly cold.
When the plate spins, your food gets more exposure to the microwave and more evenly cooked.
Here’s an article from the FDA with even more information on how a microwave works if you’d like to do a little more in-depth and technical reading on how your food gets heated up.
Issues With Cardboard Takeout Containers
The issue with cardboard and other takeout containers is that it may not evenly spread out your food to get cooked evenly and you’ll end up with some parts of your food that are scalding hot and others that are cold to the touch.
Imagine you have one of those Chinese takeout containers that holds the food in almost like a tall column. Even though the microwaves are hitting the container and the food and the microwave is spinning the food, the column of food is so dense that the outside is going to get much hotter than the inside.
See the issue?
The Best Way to Microwave Food
The best way to microwave food to avoid this issue of simultaneous scalding hot and freezing cold food in the microwave is to evenly spread your food out on a plate. Imagine that you want all your food to get evenly hit with microwaves so it all heats up evenly.
As the microwave spins, your food warms up evenly and since it’s less dense and the microwaves don’t need to penetrate as far into the food, you don’t need to cook it for as long.
There are some caveats with this, like a Hot Pocket, in the sense that you can’t evenly lay out a Hot Pocket anymore than it is already laid out. But that’s not the case with leftover food or any other food that you’ll be heating up in the microwave.
Especially with leftovers, it’s always a better idea to spread the food out evenly on a plate and microwave from there. And if you try this, only put maybe 50-75% of the time on the microwave since the heat doesn’t need to penetrate as far. The more dense your food is the longer you’ll need to leave it in the microwave, but if you make it less dense by spreading it out, you won’t need to cook it for as long.
Tips for Using the Microwave
In addition to what we already discussed above regarding microwaving cardboard, takeout containers, pizza boxes, and the best way to microwave your food, there are a few other things you should know.
Never Microwave Tinfoil
You should never microwave tinfoil because doing so can cause sparks or a fire. Microwaves can be absorbed by food, which is why they’re so great to quickly heat up food, but tinfoil cannot and thus reflect the microwaves causing them to spark and potentially cause a fire.
It’s a big no-no to microwave tinfoil and something you should never do if you want to avoid a fire.
Never Microwave Electronics
Electronics are similar to tinfoil in that they should never be microwaved. It’s questionable why you would ever want to microwave an electronic, but there has been fake information spread in the past about microwaving your iPhone to quickly charge it’s battery. That’s not true and will only cause irreparable damage to the electronics in your phone.
So we’re not sure why you would ever want to, but we figured it was important to let you know sooner rather than later that electronics should never be put in the microwave.
Add a Glass of Water to the Microwave
If you’re going to be reheating food like pizza or something else that can dry out, try adding a glass of water to the microwave when you reheat the food.
The glass of water will absorb the extra microwaves and release steam at the same time, which helps keeps your food most and avoid it drying out.
Just be careful when removing the glass of water as it can be very hot because it heats up the water fairly evenly and can cause significant burns if it spills on you.
The best option here is to microwave your food with the glass of water, then pull out your food, and wait a few minutes or until you’ve eaten your food to then pull the glass of water out. By then both the cup and water should have sufficiently cooled.
Use a Glass of Water to Clean Your Microwave
Another useful tip for adding a glass of water to your microwave is when you want to clean it. As mentioned earlier, if you add a glass of water to the microwave when heating up food, it can prevent your food from drying out by releasing steam. Well that same concept helps with cleaning.
If your microwave has baked on dirt, grime, or food stains then the steam can help loosen the baked on food stains, which then makes it easier to wipe off using a cleaning solution.
To do this, fill a glass of water about 3/4 of the way to the top, microwave it for 45-60 seconds, wait for the glass to cool, take it out of the microwave, and then wipe down the sides of your microwave with a wet cloth. That should be enough to loosen the food stains and allow them to be easily wiped clean.
If it doesn’t work the first time or there’s not enough steam, you can try this a couple times to increase the amount of steam and help loosen those food stains.
The only thing to remember is that if you’re using a cleaning solution in your microwave, then make sure you thoroughly remove that cleaning solution from your microwave after cleaning. You don’t want those chemicals showing up in your food after heating it in the microwave.
Conclusion
And there you have it! We covered quite a few topics in this article that were hopefully helpful and will allow you to use your microwave with a bit more knowledge in the future.
We covered the original question you asked when you found this article, can you microwave cardboard, which is generally no. We also covered microwaving takeout containers and pizza boxes, both of which we recommend against because there are better ways to microwave food.
And the better ways to microwave food came from learning how microwaves work, the issue with cooking in takeout containers, and the best ways to microwave your food.
Finally, we covered a few miscellaneous tips when it comes to using microwaves, such as to never microwave tinfoil or electronics, and how a glass of water can help you heat up food more evenly and even help with cleaning a dirty microwave.
Hopefully this article was helpful and answered your original question.
