What happens when you put metal in the microwave oven?

Everyone knows the rule: Do not put metal in the microwave oven or you will need to buy a new one for the damage it may cause. However, this information that many people warn may be wrong, according to the people of Gizmodo. Find out why below.

How it works

The microwave oven works thanks to the magnetrons, which are the electronic valves responsible for turning electrical energy into electromagnetic waves. This technology, originally designed for military radar systems, generates high frequency waves usually around 2.5 gigahertz.

This frequency is ideal to be absorbed by water, fat and sugar molecules within organic matter. And this energy causes them to vibrate at very high speeds, which in turn generates the heat that actually prepares the food. Contrary to popular belief, microwaves do not cook food from the inside out.

Shutterstock

The waves actually only penetrate about an inch and a half into the food. It is the conductive properties of meat and vegetables that heat all the way. The exterior elements only carry heat inside. This is why it is better to cook large cuts of meat with reduced power for longer periods to ensure that the food is cooked evenly.

However, as is well known, the air around the food does not heat up like in conventional ovens, which may be great in some cases, but in some preparations it is not possible to get the crispness and golden color seen in the other preparation. common.

Metal in a microwave oven

Containers made of ceramic, plastic or glass do not absorb the waves at the frequency used and therefore do not heat very much inside this oven. Metal, on the other hand, effectively reflects microwave energy. This is why, curiously, the inside of each oven is made of a metal box, which prevents microwaves from spreading and cooking what's nearby.

It turns out that any smooth metal sheet - the thicker the better - can be safely used in the microwave oven because they act like flat metal walls: they reflect the waves. According to Gizmodo, a foil (aluminum) could be used to protect parts of the food, preventing it from overcooking.

Even if placed under a frozen pizza, the metal foil could help brown its edges, reflecting additional energy against the bottom of the food. But does anyone have the courage to test? In any case, utensils such as pans, bowls and metal shapes are totally prohibited from entering the microwave oven.

Watch for sparks

Have you ever happened to put something in the microwave and see sparks bouncing off the food? At times, the electromagnetic field inside the furnace can be a bit confusing and generate small arcing strikes. This can be caused by common foods such as carrots (when grown in mineral rich soil) and even a simple sausage when salt and additives are not properly mixed.

Many people watch the sparks also coming out of the gold or silver friezes of porcelain plates. Now, if you happen to put a crumpled sheet of foil in the oven, you can say goodbye to the appliance.

All because, unlike sturdy microwave walls, the small, thin, sharp bits of crumpled aluminum foil cannot withstand the flow of energy and quickly heat up to fire. Any thin wrinkled edges of the aluminum foil allow this effect.

If the error is detected early enough, you can avoid the worst by immediately removing the piece of paper from the oven. Now, if the material was forgotten by covering a bowl with a meal you were preparing or just heating up, and you went to the living room to watch TV in the meantime, probably the combustion of aluminum will cause irreparable damage to the device and probably spoil other parts. from your kitchen with the flames.

Not to be fooled, the USDA gives some tips:

  • Use only the new smooth sheet of aluminum foil as the wrinkled sheet can cause sparks and flame;
  • Cover no more than 1/4 of the food with aluminum foil;
  • It makes no difference which side of the sheet (glossy or matte) faces outward;
  • Do not place the sheet closer than an inch from the oven walls;
  • If you see sparks, immediately remove the aluminum cover.

* * *

Anyway, when it comes to microwaves, it's best not to mess with the winning team, right? Curious Mega makes the fact scientifically clear to you, but only recommends that you test the use of foil in a completely safe manner. In all cases, continue to use only glass, plastic or ceramic in addition to microwave-specific utensils.