Why Don't We Eat Pop-Quinoa?

Popcorn is unique among grains due to its ability to pop into a fluffy snack. This is due to its hard outer hull and the physics of heating, which causes the internal pressure to build until it bursts. Unlike other grains like quinoa or rice, popcorn expands significantly more and has a unique popping mechanism involving a leg-like structure that propels it upwards. This makes popcorn not only larger but also more dynamic in its popping behavior.

What role does steam play in the popping of popcorn?

Explain why popcorn can expand more than other grains when popped.