Image of person covered in popcorn besides their head

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How Popcorn Exploded

This puffed-up snack has a history that goes back thousands of years!

By Alice Sun

From the October/November 2024 Issue

Learning Objective: Students will summarize how popcorn became a popular snack food and will create their own flavor of popcorn.

Lexile: 790L; 550L

Key Focus Area: Matter, Traits,

Other Focus Areas: Earth's Materials & Systems, Human Impacts, Engineering, Measurement & Data

As you read, think about what caused popcorn to become a popular snack food.

Tahila Mintz/The New York Times/Redux

Indigenous farmer Angela Ferguson holds a braid of corn. She braids the husks together so the kernels dry out.

Pop-pop-pop! That’s the sound of tiny corn kernels transforming into a puffy, crunchy snack! Salty or sweet, popcorn is the perfect treat for movie theaters, sports games, or your couch!

Humans have been munching on popcorn for a very long time. Indigenous people in Mexico and Central America started growing corn more than 10,000 years ago. It looked very different from the corn you see at the grocery store today. But it was used to make the earliest version of popcorn.

Over time, popcorn changed and exploded in popularity around the world. Here’s how it happened!

Pop-pop-pop! That’s the sound of tiny corn kernels. They’re turning into a puffy, crunchy snack! Popcorn can be salty or sweet. It’s the perfect treat for movie theaters, sports games, or your couch!

People have been eating popcorn for a long time. Corn was first grown by Indigenous people in Mexico and Central America. That was more than 10,000 years ago. That corn wasn’t like what you see at the grocery store today. It looked very different. But it was used to make the earliest popcorn.

Popcorn changed over time. It became popular around the world. Here’s how it happened!

The History of Corn

Burazin/Getty Images (Corn); DANIEL SAMBRAUS/Science Source (Wild Grass)

Today’s corn came from a type of wild grass (right).

The earliest type of corn, first grown thousands of years ago, is an ancestor of today’s corn. It’s called teosinte (tay-oh-sin-tee). Like modern corn, teosinte is a type of grass that has a cob and a protective husk. It’s also rich in nutrients. But unlike modern corn, it’s difficult to eat. Its kernels are small, and its husk is thick.

To make the kernels easier to eat, ancient people figured out how to use heat to pop open their hard shells. “Scientists think that this was the first way humans ate corn,” says Alma Piñeyro-Nelson, a scientist who studies plants. Archaeologists have found cobs with puffed kernels in Peru that are more than 6,700 years old!

Over time, teosinte transformed. As societies began farming, people chose to grow seeds from plants that had bigger, softer kernels and easier-to-peel husks. Each new generation of corn inherited these traits. Eventually, the plant had turned into modern corn. This corn became a key part of human diets around the world.

Corn grown thousands of years ago was called teosinte (tay-oh-sin-tee). It’s the ancestor of modern corn. It’s a type of grass. It has a cob and an outer husk. It’s also rich in nutrients. But unlike modern corn, it’s difficult to eat. Its kernels are small. And its husk is thick.

Ancient people learned to make the kernels easier to eat. They used heat to pop open their hard shells. “Scientists think that this was the first way humans ate corn,” says Alma Piñeyro-Nelson. She’s a scientist who studies plants. Archaeologists have found cobs with puffed kernels in Peru. They’re more than 6,700 years old!

Teosinte changed over time. People began farming. They chose to grow seeds from plants with bigger, softer kernels. The plants also had easier-to-peel husks. Each new crop of corn inherited these traits. Eventually, the plant turned into modern corn. This corn became a key part of people’s diets around the world.

Rise to POP-ularity

As corn became more popular, so did its puffed-up cousin—popcorn! Popcorn is a special variety of corn. Its kernels have dry, hard shells. When the shells are heated, tiny water droplets inside the kernel vaporize. Pressure builds until—POP! Sugars inside the kernel quickly expand, forming a puff (see How Popcorn POPS!, below).

For many years, people made popcorn in small batches on the stove. Eventually, they came up with faster, easier ways to pop corn. In the 1890s, inventor Charles Cretors created the world’s first popcorn machine. The steam-powered device heated kernels in oil. It was light enough to move around, allowing vendors to sell popcorn in the streets.

Corn has become more popular all over the globe. And so has its puffed-up cousin. Popcorn is a special type of corn. Its kernels have dry, hard shells. People heat the kernels. That causes tiny water droplets inside to vaporize. The pressure builds. POP! Sugars inside the kernel quickly expand. That forms a puff (see How Popcorn POPS!, below).

Here’s how people made popcorn for many years. They popped it in small batches on the stove. They came up with faster, easier ways to pop corn over time. Charles Cretors was an inventor in the 1890s. He created the world’s first popcorn machine. It was a steam-powered device. It heated kernels in oil. It was light enough to move around. That allowed people to sell popcorn in the streets.

How Popcorn POPS!

Illustration by Eyewash

1. A kernel has water particles inside it. Heat makes the particles move faster. Eventually, they turn into water vapor, a gas.

Illustration by Eyewash

2. Pressure builds inside the kernel. It causes the shell to burst, letting the gas escape. That’s when you hear the “POP”!

Illustration by Eyewash

3. The heated water vapor cooks the insides of the kernel. It bursts and puffs inside out.

How does the water in a popcorn kernel help make it pop?

How Popcorn POPS!

Illustration by Eyewash

1. A kernel has water particles inside it. Heat makes the particles move faster. Eventually, they turn into water vapor, a gas.

Illustration by Eyewash

2. Pressure builds inside the kernel. It causes the shell to burst, letting the gas escape. That’s when you hear the “POP”!

Illustration by Eyewash

3. The heated water vapor cooks the insides of the kernel. It bursts and puffs inside out.

How does the water in a popcorn kernel help make it pop?

In the 1920s and 1930s, movie theaters began selling popcorn. The theaters were a new attraction at the time. At first, snacks were banned to prevent spills and messes. But when ticket sales dropped, theaters started selling popcorn to bring in moviegoers. The cheap and easy-to-make snack was a hit!

It wasn’t until 1981 that the first microwavable popcorn was sold. The invention brought the joy of movie theater popcorn to the comfort of people’s homes!

Movie theaters began selling popcorn in the 1920s and 1930s. Theaters were new at the time. Snacks were banned at first. Theaters didn’t want spills or messes. Then ticket sales dropped. Theaters started selling popcorn to bring in customers. The cheap and easy-to-make snack was a hit!

It wasn’t until 1981 that microwavable popcorn was sold. The invention brought the joy of movie theater popcorn to people’s homes!

Popcorn Today

Today popcorn is a staple snack across the U.S. Americans eat about 3.5 billion gallons of it a year! It comes in many flavors. At theaters, moviegoers munch on buttery popcorn. Amusement parks and baseball stadiums sell salty, sweet caramel corn.

Popcorn also remains popular in other parts of the world, including Mexico, where the snack originated long ago. There you’ll find the crunchy kernels served with a sprinkle of salt and chili powder. “Popcorn was always a part of people’s diets,” says Piñeyro-Nelson. “It’s a very ancient snack.”

Standing the test of time, this beloved treat is here to stay. Salty, sweet, or spicy: How do you like yours?

Today popcorn is a staple snack across the U.S. Americans eat about 3.5 billion gallons of it a year! It comes in many flavors. People munch on buttery popcorn at theaters. Amusement parks and baseball stadiums sell salty, sweet caramel corn.

Popcorn also remains popular in other parts of the world. That includes Mexico, where the snack came from long ago. There the crunchy kernels are sprinkled with salt and chili powder. “Popcorn was always a part of people’s diets,” says Piñeyro-Nelson. “It’s a very ancient snack.”

This beloved treat seems here to stay. Salty, sweet, or spicy: How do you like yours?

She Built a Popcorn Business!

By Jenny Morber

It all started with a trip to the orthodontist. That’s when 15-year-old Kaylynn “Kakes” Martin of Saginaw, Michigan, learned she needed braces and dental surgery. But at the time, in 2020, money was tight for her family. Because of the pandemic, Kaylynn’s mom had to close her beauty business.

Kaylynn had an idea to help her family pay for dental care. She would start her own business! But what kind of business? Kaylynn asked herself: “What do I like? What do people like?” And it came to her—popcorn!

Back then, Kaylynn only knew how to make microwavable popcorn. She watched online videos to learn how to make popcorn on the stove. Kaylynn then began creating her own flavors of kettle corn, a type of sweet, salty popcorn. Family and friends tested her recipes.

In October 2021, Kaylynn entered her business idea in a competition and won a $2,000 prize! That helped Kaylynn start her business—Kakes the Great Popcorn Co. She sold her first kettle corn at her mom’s reopened beauty shop. Today her company sells to stores across Michigan—and even has its own store!

Kaylynn’s mom and twin brother, Kristian, have helped grow the business. Kaylynn’s confidence has grown too. “I deserve to sit at a table full of adults,” she says. “They can learn from me, and I can learn
from them.”

It all started with a trip to the dentist in 2020. Kaylynn “Kakes” Martin learned she needed braces and dental surgery. The 15-year-old lived in Saginaw, Michigan. Money was tight for her family at the time. The pandemic had started. And her mom had to close her beauty business.

Kaylynn had an idea. It could help her family pay for dental care. She would start her own business! But what kind? Kaylynn asked herself: “What do I like? What do people like?” And it came to her. Popcorn!

Kaylynn knew only one way to make popcorn back then. She popped it in the microwave. She watched online videos. They showed how to make popcorn on the stove. Kaylynn then began creating her own flavors of kettle corn. It’s a type of sweet, salty popcorn. Family and friends tested her recipes.

Kaylynn entered her business idea in a contest in October 2021. She won a $2,000 prize! That helped Kaylynn start Kakes the Great Popcorn Co. She sold her first kettle corn at her mom’s reopened beauty shop. Today her company sells to stores across Michigan. And it even has its own store!

Kaylynn’s mom and twin brother, Kristian, helped grow the business. Kaylynn’s confidence has grown too. “I deserve to sit at a table full of adults,” she says. “They can learn from me, and I can learn from them.”

video (2)

Activities (14)

Quizzes (1)

Answer Key (1)

1. PREPARE TO READ (10 minutes)
Compare unpopped kernels and popped popcorn before watching a slow-motion video.

Prepare two kinds of popcorn in advance: Place 20 unpopped popcorn kernels in a container, like a clear measuring cup or glass jar. Place 20 popped kernels in an identical container. First, show students only the unpopped kernels. Ask: How much more space do you think this popcorn will take up when popped? Explain your reasoning.

Reveal the popped popcorn and note its volume, or the amount of space it takes up. Tell students this popcorn isn’t for eating. Give student pairs a popped kernel and an unpopped kernel and have them record what they notice about each. Discuss their observations. Tell them they are going to see how popcorn pops at a slowed-down speed.

Play the video “Popcorn in Slow Motion.” Ask: Were the changes gradual or sudden? (sudden) Could popped popcorn be changed back to unpopped kernels? (no) What do you think causes unpopped kernels to change? (Ideas will vary but may include a heat source, like a microwave.)

2. READ AND SUMMARIZE (20 minutes)
Read the article and summarize how popcorn became a common snack.

Tell students they are going to learn how popcorn became popular. Read the article aloud, pausing to discuss important ideas like how teosinte gradually changed into modern popcorn or how it became popular across the U.S.

Read the sidebar “How Popcorn Pops!” Ask students what changes in a popcorn kernel it describes. (e.g., The shell bursts or the starch inside the kernel puffs up as it is cooked.) Have students connect the steps in the article’s sidebar to the video’s slowed-down popping of a popcorn kernel. Replay the video if needed.

Have students use the article as a reference as they complete the Quick Quiz. Reconvene to discuss answers.

3. RESPOND TO READING (30 minutes)
Read about a student’s popcorn business and propose a popcorn flavor.

Play the video “Taking Care of Business With Kaylynn Martin.” Then have student volunteers read aloud the paired text “She Built a Popcorn Business!” Discuss what students found interesting or inspiring about Kaylynn and her business. Share and preview the Design a Popcorn Flavor activity. Allow students to work in pairs or small groups to brainstorm new popcorn flavors and complete the activity. Encourage students to use sensory details in their writing and vivid colors in their drawing.

STEM INTEGRATION

MATH: Interpret a circle graph about popcorn’s popularity (CCSS Math: 3.MD.B.3)

Ask students: How often do you eat popcorn? Let students turn and talk. Then share the activity Circle Graph: How Many Bags of Popcorn? and preview it. After students have answered the questions, discuss their responses. To extend, have students complete the activity’s “Take It Further!” prompt.

ELA: Research a food’s place of origin and locate it on a map (CCSS ELA: W.7)

Have student pairs research where a food, like a fruit, vegetable, or grain, originated. Ask them to draw the food on a sticky note, adding its name and its location of origin (either a country or a continent). Project a world map and have students stick their note in the correct region. Discuss foods that have become parts of cuisines far from their origin. (e.g., tomatoes or chocolate)