[ANSWERED] Why Does An Empty Plate Not Heat Up In The Microwave?

Remember how placing a cup of water along with your pizza slice in your microwave makes the pizza go all fluffy and soft on the inside, while the crust is crispy? Well, this hack involves a little bit of science along with the DIY.

A lot of times our minds wonder, why isn’t the world flat? Where does chocolate milk come from? And why does an empty plate not heat up in the microwave?

Well, we don’t have answers to the first two, but for the third question, we do have something. Microwaves need water molecules to heat up any type of food. As an empty plate doesn’t have water, it doesn’t heat up. 

We know how confusing it is because sometimes you find a plate is heating up slightly. Then why sometimes it doesn’t? Let’s talk in-depth about that. 

why does an empty plate not heat up in the microwave

Reason Why An Empty Plate Does Not Heat Up In The Microwave

The first thing you have to know about a microwave oven is how it works. It works by producing electromagnetic waves and it travels and vibrates water molecules. As the radiation travels through the food, the water inside it gets vibrated creating energy, which turns into heat.

It’s that simple. But what about putting an empty plate in a microwave? It doesn’t heat up due to the same principle. No water, no vibration, no energy, no heat. The electromagnetic waves get reflected around the walls of the microwave and don’t react with the plate at all.

But there are instances that the plate heats up in places. This is due to the presence of some moisture. And also, glass plates, although dielectric, heat up a little without water. Why? Because glass reacts to electromagnetic waves a little due to its chemical compound. Hence, heats up.

Metal plates reflect microwaves more than any other material. This causes a chain reaction that damages the arch. This is why it is never suggested to use metal utensils in the microwave.

If you really want to heat up a plate in the microwave, you will have to pour a little water onto the plate and then place it in the microwave. This will let the water heat up along with the plate. 

But for safety reasons, you should not do this. As the water will heat up, the plate will heat up unevenly. Causing heat spots on the plate which will get chipped out over time. 

Frequently Asked Questions and Answers (FAQs)

Why does a microwave heat food but not plate?

Microwave works by vibrating liquid, fat, and sugar molecules. So it can vibrate the water and fat in the food heating it up. As there is no water or fat inside the plate, the microwaves don’t react with it. Hence not heating the plate up but the food. 

Why does an empty paper plate not heat up in the microwave?

Empty paper plates, ceramic, pyrex, or any plates don’t have any water or moisture in them. And this is needed for the microwaves to react. So an empty paper plate or any plate does not heat up in the microwave. 


Sometimes it is necessary to heat up a plate, although we don’t have any idea why. Maybe a certain dish requires it, or you just don’t like touching a cold plate. So if you are keen on heating up a plate in the microwave, we suggest you don’t do it. But you can do it by cutting down its life expectancy placing some water on the plate and then microwaving it. Don’t make us say, ‘We told you so’ when the plate cracks!

Similar Posts

Leave a Reply

Your email address will not be published. Required fields are marked *