Wonder Contributors

Many of our Wonder Friends have been curious about this yummy treat, so we’re revisiting the science of popcorn! Thank you, Loren, Izzy, Samantha, Elijah, Carolyn, Kimberly and Micah!

Whether you’re cheering at a ballpark, checking out the latest box office release, or settling down on the sofa for family movie night, popcorn has been one of America’s most beloved snack-time sidekicks for decades.

If you’ve ever wondered what’s going on inside your microwave as you pop up this tasty treat, grab a front-row seat and find out what all the noise is about. It’s time to go behind the scenes with one of the world’s oldest snack foods!

So what makes popcorn pop? And why doesn’t all corn pop when heated? The answer is a matter of simple science. Popcorn is a special kind of corn. Of all the types of corn, popcorn is the only variety that pops.

Inside each kernel of popcorn is a tiny droplet of water surrounded by a hard shell called a hull. As the popcorn is heated, the water turns into steam, which builds pressure inside the kernel. When the hull can no longer contain the pressure — POP! — the kernel explodes and a fluffy new piece of popcorn is born.

In America, consumption of popcorn rose steadily with the increasing popularity of television sets in the home during the 1950s. As more people began staying home and tuning into their TV for entertainment, they found themselves craving a salty snack. The natural choice, of course, was popcorn!

Long before the television was ever invented, however, popcorn was a part of American culture. Some historians even suggest Native Americans introduced the Pilgrims to popcorn when they brought it to the first Thanksgiving feast.

Though Americans consume more popcorn than any other country in the world today, archeologists have found popcorn kernels in New Mexican caves they believe to be more than 4,000 years old, suggesting this savory snack has been a part of cultures around the world for centuries.

When Spanish explorers arrived in Mexico, they discovered the Aztec Indians used popcorn to make the garlands, headdresses and ornaments they wore during “popcorn dances.” The Indians used to tell a legend explaining the popcorn phenomenon.

The legend claimed a tiny demon lived inside each kernel of popcorn. When the demon’s house was heated, he would get so angry he would explode!

38 Join the Discussion

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    • You are a GREAT WONDERer, Dustin! Way to go! Every kernel of popcorn has a tiny droplet of water inside of it that is surrounded by a hull (hard shell). When the popcorn is heated, the water droplet turns into steam, building pressure inside the kernel and causing it to POP, POP, POP! We encourage you to re-explore this Wonder to learn more about popcorn! :-)

    • We love popcorn, too, Syd! It’s fun to eat at the movie theater, at home during family movie nights, or as a snack anytime of the day! Thanks for sharing your comment with us! :-)

  1. We have been learning about popcorn because our town, Marion, Ohio, has a popcorn festival every year. It is this weekend and we have done all things popcorn this week. Thanks for the great article and the fun videos!

    Room 176

    • That sounds like such a fun (and tasty) festival, Room 176! We hope you have a really awesome time this weekend! Thanks for including us in your popcorn WONDERing!! :)

    • Thanks for WONDERing with us, Taylor M! When popcorn hasn’t popped and is still in kernel-form, it’s just too hard for our teeth to break open. Trying to break open the kernel with your teeth could hurt and even damage a tooth, so it’s best to not try it! :)

    • Hi, Torrance H.! Each popcorn kernel is covered in a hard shell called a hull. That shell is so hard, that our teeth have a tough time breaking through it, causing pain when you try to bite into it or worse, a piece of your tooth to be broken off!

  2. Levi-Popcorn pops when the heat gets hot.
    Amber-I was eating the popcorn at my house and we ran out.
    Sanaa-Popcorn pops in a machine.
    Aaden-I ate popcorn when it was night time with my grammy.
    Harmony-We eat popcorn with my family.
    Jordyn- The popcorn pops.
    Rian- I eat popcorn all the time.
    Jacob- My mommy gave me a picture of popcorn.
    Brayden- I love popcorn with white salt.
    Makaylah- My favorite popcorn has pepper.
    Mrs. Utter- I love caramel popcorn.

    Matthew- I want to learn about people playing basketball.
    Maryann-I want to learn about books.
    Sean-I want to learn about playing outside,

    • Thank you for sharing all of your WONDERful comments, Mrs. Utter’s Class! We’re so glad you are hanging out with us in Wonderopolis! We WONDER if you can think of other types of food that make noises when you cook them (like when you boil, or simmer, or fry them)! :D

    • That’s a great question, McKinsie H.! Here’s what we found at http://www.popcorn.org: “Kernels that do not pop are known as ‘old maids.’ They do not have sufficient water contained within the starch to create the build up of pressure needed to pop the kernels.” Thanks for hanging out with us here in Wonderopolis! :)

  3. Dear Wonderopolis
    After reading this, we have some questions.
    Why did they say that their are demon’s in the kernel? Who was the first person
    to make popcorn? Why is popcorn a snack? Where was popcorn invented?


  4. Who wrote this article about popcorn? We are doing a Science Fair project and needs detail information on the author and when it was written PLEASE ASAP
    Thank you Cheri

    • Hi Cheri!

      It’s always important to cite your sources when doing a report. The official Wonderopolis Permissions Policy states:

      Wonderopolis materials may be cited or excerpted in periodicals, books, and educational materials under the following stipulations:

        1. A URL of the material referenced is provided so that readers may access it online
        2. Inclusion of the following branding information: “Wonderopolis is brought to life by the National Center for Families Learning.”

      Since our Wonders are sometimes updated, the proper way to cite the publishing date is to list the date you consulted our page for your research. Good luck on your science project!

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Have you ever wondered…

  • What makes popcorn pop?
  • Does all corn make popcorn?
  • How long have people been eating popcorn?

Wonder Gallery

Try It Out

Are you hungry yet? If so, get popping with the following activities. Be sure to ask a friend or family member to give you a hand!

  • The transformation from popcornkernel to popcorn puff happens in the blink of an eye. A neat video at Popcorn.org slows down the popping process to give you a slow motion look at what’s really going on when you hear that signature pop.
  • What better way to celebrate learning about popcorn than eating popcorn! Take a field trip to a local grocery store with an adult friend or family member. Find the popcorn section and check out all the varieties of popcorn available. Pick a couple to try at home, then head home to get popping! Which type of popcorn is your favorite? What toppings, if any, do you like?
  • Though there may not have been a kernel of truth to the tale of the popcorn demon, inventing stories about food can be a fun way to stimulate imagination and conversation around the dinner table with your family. Challenge yourself to get creative with your favorite (and least favorite) foods and watch as broccoli turns into a miniature forest, blueberries become tiny bowling balls, and flying saucer pancakes make their way past a pad of butter moon right before your eyes.

Still Wondering

Science NetLinks’ Technology at Home site lets you go back through the twentieth century to find out when everyday items, such as computers, TVs and microwave ovens, first appeared in homes.

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