You will need:
- Popcorn kernels
- Deep sauce pan with a transparent lid
- Oil
- Grinding stone
- Stove
The next time you’re hungry for a snack, eat
and learn something new with popcorn.
INSTRUCTIONS
- Ask an adult to cook you some popcorn. But before he/she does so, understand why and how the popcorn kernels pop.
- Take a few kernels and crush them slightly with a grinding stone. Do not flatten them completely; just smash them till they crack open.
- Add these broken kernels to a few normal kernels into a little oil in a deep sauce pan, and place it on the stove.
- Cover the sauce pan with a transparent lid so that you may see what is happening. But be careful.
- Once your kernels have popped, remove the sauce pan from the heat and with the help of the adult have a look inside. What happened to the broken kernels?
RESULT
The broken kernels don’t pop because of the way the popcorn is formed. Popcorn kernels consist of starch surrounded by a hard husk like shell. When these kernels are heated, the husk shell does not let the heat escape. The temperature keeps rising to almost 100° celsius, making the water-content inside turn to steam, mixing with the starch to create a jelly-like texture. The temperature finally goes as high as 180° celsius before the pressure cracks the shell. It makes the jelly come rushing out. Due to normal atmosphere, the pressure drops, instantly creating foam, which we call POPCORN! But, moisture inside a cracked shell escapes in the form of steam.
