Each kernel of popcorn contains a certain amount of moisture. As the kernel is heated past the boiling point, water in the kernel begins to turn to steam. This steam escapes as fast as it forms, but in the tightly sealed popcorn kernel, the steam is held tight by the pericarp and the pressure starts to build until the pericarp (outer hull) suddenly ruptures, causing a small explosion.
My relationship with popcorn has been pretty intense since my school days. During our summer vacation we used to go to our ancestor’s pind (village) in Punjab(India) and we used to relish popcorn made by “CHHOR” (one who pops the corn) . She would keep one-fourth of the maize for her services which we would give her to pop. She would put a large wok on the clay stove and put sand in it. Once the wok is hot, she would put all the remaining maize in it, In few seconds it would start popping with crackling noise. A maize pops at 175 degree C. Amazing !!Then she would use a large perforated spoon to take popcorn out of the hot wok and the hot sand would flow smoothly through the holes of the spoon. My aunt would spread her “Dupatta” to collect all the hot popcorn. There was only one “Chhor” in our village ………. this services ceased to exist after her demise. I still rate it as one of my best popcorn I have ever tasted.
Later in my teens, Mom would buy those small pouches of raw corn kernel presoaked in oil and put it in an already heated pressure-cooker. It would start popping with banging noise inside the pressure cooker and remind one of tribal drum-beat.
Then finally we started putting it in microwave, which is faster and very convenient with different flavours to relish. Although at times, it would turn black due to over-heating and tastes awful.
Amazing, popcorn has traversed this long journey of 5600 years and still relished by millions.