This fun Popcorn science experiment will sneak in science and have your kids appreciating the mechanics of nature, let alone be amazed by it! But before you get on the popcorn experiment for kids, pop the question — Why does the Popcorn pop?
Why Does Popcorn Pop?
Simply put, popcorn kernels contain teeny-tiny amount of water inside them. When this water is heated, it changes into steam. This steam builds up pressure inside the kernel and needs to escape. And so, it forces its way out, making the kernel to POP and spill the insides!
That’s the easy explanation of why the popcorn pops for kids, especially the younger ones. But for older kids — tweens & teens, you can delve deeper with this step wise explanation of why popcorn pops?
1. The Magic is Inside The Kernel
To pop, kernels need just the right amount of moisture inside them and just enough thickness. The moisture of 13.5-14% is ideal to make the kernels pop.
Not all corn kernels can pop, thanks to the difference in the thickness of the hull or outer shell, technically called a pericarp.
2. Heat Turns Kernel Into Steam Chamber
When the kernel is heated, the water inside it evaporates and turns into steam. The steam expands inside the kernel, cooking the starch in the grain and putting pressure on the hull.
At a temperature of about 180 C, the pressure build up inside the kernel reaches around 135 pounds per square inch. At this point, the hull cannot take it anymore and is ready to burst open.
3. Boom — Popcorn is Served!
Finally the hull bursts open and the steam is release! Along with it, the soft inside of the kernel, called endosperm, expands and explodes. This puffed soft starch then cools into the fluffy white popcorn you know!
4. What’s That Sound?
That “pop” sound you hear is actually a mini explosion from the steam breaking through the shell! So when you hear the pop, know that Popcorn is getting cooked!
Next time when your kids ask for popcorns, make sure to pop this question to sneak in fun science! After all, nothing can beat hands-on science activities that are accompanied with the world’s undoubtedly most loved snack – the humble popcorn!
Related: Explore the Science Behind Why Onions Make You Cry!
Popcorn Science Experiment
This easy science experiment will help kids grasp the science behind popping popcorns. It’s a hands-on way to understand the role of heat, pressure and water, present in the kernel, play in popping the popcorns.
Supplies:
- Popcorn kernels
- 2 Pots
- Stove
Instructions
1. Label the pots as Pot A and Pot B. Add equal amount of corn kernels in each.
2. Add 1 teaspoon butter in each pot.
3. Put Pot A on high heat and Pot B on low heat for five minutes.
4. Turn off the stove after five minutes and see which pot has most popped popcorns. Record your observations.
Popcorn Science Experiment
What do you think which pot will have most popcorns? Can you guess why?
What is Happening?
On low heat, the water in the kernels is slowly heated to form the vapour. This gradual heating of water does not create high enough pressure,135psi, for the hull to break open. Also on low heat, the vapour starts escaping through smaller vents present in the kernel making fewer kernels pop.
On the other hand, high flame quickly turns the water present in the kernel into steam building pressure to pop the kernel open. This is why more kernels pop on high flame compared to low flame.