When microwaving a bag of popcorn, why doesn’t the first kernel that is popped burn by the time the last kernel is popped?

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When microwaving a bag of popcorn, why doesn’t the first kernel that is popped burn by the time the last kernel is popped?

In: Chemistry

14 Answers

Anonymous 0 Comments

Oh it does. Unless you don’t want all the kernels popped. Then you have a bunch of kernels in the bottom of the bag.

Anonymous 0 Comments

Does it not for you? I burn them all the time. See what happens is that when the first one gets popped, there are still so many of them in the bag that they soak up the heat still. If you let them keep going, the first ones that popped will definitely burn.

Anonymous 0 Comments

how are you able to pop all the kernels without burnout?

Anonymous 0 Comments

Microwaves stimulate molecular bonds found in water, plastics, and some other materials. So the heat is focused in the water in the bag which takes a ton of energy to turn into steam and all the water gets turned into steam before it can pass 100C/212F so this regulates the internal temperature.

Anonymous 0 Comments

Microwaves are effective at heating water. When the miniscule amount if water in the kernel flashes to steam, and explodes, you are left with a dryer popped corn.

It will still burn, but most of the energy is being absorbed by the water aka, the unpopped kernels

Anonymous 0 Comments

Microwaves are really good at heating water. Dry things don’t heat very well compared to wet things.

When you start microwaving a bag of popcorn, almost all the moisture is inside the kernels, and so they absorb the microwaves and kernels begin to heat up. A kernel pops and becomes popcorn.

Microwaves continue to be absorbed by the kernels full of moisture. The dry popcorn is largely unaffected. Kernels continue to pop.

Eventually there are almost no kernels left, they have all popped into popcorn. Their moisture was effectively protecting the popcorn by sucking up all the microwaves, but now there are almost no kernels full of moisture to suck up the microwaves, and instead the popcorn is sitting in a cloud of super-heated vapor. The popcorn begins to burn

Anonymous 0 Comments

Just wanted to add that a bag of microwave popcorn actually has a metal layer in the bag. That is why it says to only put it a ceran way.

The metal layer getting really hot helps the popcorn pop.

After a certain amount of time the metal layer actually gets so hot it will burn the popcorn or maybe even start a fire.

If ever notice, a bag that only got a tiny bit burned, the burned popcorn is from the side of the bag that was down.

It wouldn’t happen if you just put a spoon popcorn kernels in the microwave.

Once they pop they don’t really absorb any more energy from the microwave.

They only burn if there is a hot metal layer underneath them.

Why do they do that?

Well it helps transfer heat and helps it pop up really fast.

The downside is you might make your entire house stink really bad if you cook it too long.

I recommend hot air poppers, or if you like to cook,. Do it the old way

Coconut oil is awesome, any oil works.
Do the 2 spoons of oil and a 1/4 cup of popcorn into a pot with a lid.

Takes 5 minutes, way more tasty.

I like olive oil and sea salt and some black pepper.

Anonymous 0 Comments

A lot of the answers miss the fact that only a small patch in the middle of the bag is catching the majority of microwave energy, converting it to heat. The kernels don’t see much of it, despite moisture content.

As the kernels pop, they become less dense and float towards the top of the pile, while the unpopped ones generally fall to the bottom (where the heat patch and oil are). If left too long, it is the popped kernels nearest this patch that may burn first, along with some of the outliers at the corners of the bag.

Anonymous 0 Comments

Good question.

Microwaves heat up different things differently depending on how they absorb them. That’s why some containers are microwave safe and some will melt if you put them in.

Water absorbs microwaves really well, that’s what heats up when you microwave something mainly…that’s why it has a funky texture when it cools down. All the water is boiled out of it.

Kernels pop because they have moisture inside them and when it heats up it builds up pressure and that is what makes them pop. Once they pop they heat slower because the water is gone though. You can still burn them if you go too long though.

Anonymous 0 Comments

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