This week, Roy has decided to add a new section into his creations. He has noticed that the children are fascinated by simple science experiments and constantly asking how and why things happen. He decided it would be great if occasionally we could intersperse our cooking and craft with experiments and thought that the science behind popcorn would be a perfect introduction - even better, the results are edible! The children have been using the microwave popcorn bags and noticed that sometimes very little of the corn inside actually pops. Sometimes, they have tried to give the bag longer in hopes that the popping will eventually occur, but often this results in burned corn kernels with no more popping. So why does popcorn pop, and more importantly, why does it sometimes refuse to pop!
For this experiment, Roy and I decided it would be best to cook the popcorn the 'old fashioned' way, using a saucepan. We can watch what is happening and even better, Roy always finds that you get a much higher success rate of corn popping if you do it this way. Since most of the children didn't know how to cook popcorn in a saucepan, first - the recipe!
You Will Need:
- A saucepan with a lid - Roy used one with a glass lid so we could see what was happening
- 1/4 cup popping corn
- Cooking oil - you will need enough to form a thin layer over the bottom of the saucepan. We found that about 2 tablespoons was right for our pot.
- Flavourings - The most classic is melted butter and salt, but Roy used a Creole spice-mix on his as well which was very tasty. We used a small knob of butter, about 1/2 a teaspoon of salt and a teaspoon of the spice-mix.
- A serving bowl
Method:
- Put your saucepan onto a hotplate and start heating it up.
- Put a thin layer of oil into the pan and wait for it to heat up.
- Add 1 kernel of corn as a tester to see if the oil is hot enough. It should spin slowly in the oil. When it is spinning nicely . . .
- Add your popcorn kernels and quickly put the lid on.
- Soon, you will hear (and if you have a clear glass lid - see) the popcorn popping.
- Shake the saucepan by its handle so that unpopped kernels fall to the bottom - as the popcorn pops it expands and some of the unpopped kernels might be pushed up and out of the oil.
- When you stop hearing the popping take the pan off the heat but DO NOT take its lid off yet.
- Shake the pan around for a moment or two to ensure the popping has stopped and also to cool the contents a bit - remember you are dealing with hot oil so don't try taking the lid off early or you might get hurt!
- Pour your popcorn into a bowl and add your butter to the hot pan. You don't need to put the pan back on the heat, the butter will melt in the left-over heat.
- Add the melted butter to the popcorn and season with salt and spice-mix (if you choose to use one). Shake and stir to disperse, and enjoy.
What Is Happening?
Popcorn is the corn kernel which corn would use to create new plants. Inside there is lots of starch which the plant would normally feed off until it grew some leaves it photosynthesize with (capture and convert sunlight into plant food). The kernels also have moisture in them and when they begin to heat up this tries to turn into steam. The moisture has a problem though - the corn kernel has a mighty tough shell which can actually contain the pressure and stops the water converting to steam. So, the water just keeps heating up, building up more and more pressure inside the shell. The moisture inside begins to alter the starch into a type of jelly and this is the 'death knell' for the corn kernel. Eventually, the combined pressure of the water trying to turn into steam and the jelly gets to be too much for the shell and it splits, allowing the water to suddenly and immediately boil and escape as steam. The explosion of steam both forces the jelly out of the kernel and cooks it, making it into the foamy popcorn which you know!
So, this explains how popcorn works, but we still haven't answered why you sometimes get tiny pieces of popcorn, which are more kernel than actual popcorn, or kernels which don't seem to have popped at all. There is a very simple answer for this. Popcorn needs a massive amount of pressure to work so if the kernel is somehow damaged that pressure may not be achieved. Sometimes enough pressure is built up to allow a tiny piece of popcorn to be created, but sometimes the kernel is too damaged to even allow that much. The moisture can escape through the damaged kernel and so the pressure doesn't build and the explosion has nothing to power it. You will probably have a few pieces of damaged popcorn at the bottom of your bowl which split but didn't pop, like the ones Roy is holding below. If you don't you can create kernels to see what happens to non-popping popcorn kernels by squishing them with a pair of pliers or even a gentle tap with a hammer.