Pop! Mateo Researches Popcorn

Source 1: How Popcorn Pops (from a science book)

1Popcorn is a special kind of corn. It grows on tall corn plants, but its kernels are small and very hard. Each kernel has a tough outer shell called the hull. Inside the hull is a starchy center that holds a small amount of water.

2When a kernel is heated, the water inside it turns into steam. Steam needs much more space than water does. The hull is so strong that the steam cannot get out. The steam pushes harder and harder on the inside of the shell. At last, the hull bursts open with a loud pop!

3As the hull breaks, the hot starch puffs out and cools into the white, fluffy shape you know. A popped kernel is many times bigger than a kernel that has not popped. Most other kinds of corn do not pop well, because their hulls are not strong enough to trap the steam.

Source 2: Popcorn Facts (from a science center website)

1Popcorn long ago. People in the Americas have grown and popped corn for thousands of years. Scientists who study the past have found very old popcorn kernels in some places.

2What makes it pop. Every popcorn kernel holds a little bit of water. Heat turns the water into steam, and the steam breaks the shell open.

3Why some kernels stay hard. Not every kernel in the pot pops. Some kernels are too dry inside to make enough steam. Others have a tiny crack in the shell, so the steam leaks out before it can push hard enough.

4Popcorn today. Today, popcorn is a favorite snack at movie theaters and fairs. Many families make it at home, too. People eat it plain or with toppings such as butter and salt.