A peek behind the pop:
the science and nutrition
of popcorn


We didn’t believe her at first but food scientist Dr Rachel Edwards-Stuart has convinced us that popcorn isn’t magic, but science. Really, really delicious science.

So, don your lab coat and goggles and join us as we take a look at the science behind the pop. Plus, we’ll answer the age-old question: can something so delicious really be good for me?

The king of corn

There are many different types of corn – flint corn, dent corn, flour corn, sweetcorn, the list goes on and on. But only one very special kind pops to form the delicious fluffy snack we all love so much: the variety known as popcorn.

What makes popcorn pop?

Like most grains, popcorn contains a certain amount of naturally occurring water. As the popcorn kernel is heated, this water boils and becomes steam, causing the inside of the kernel to expand. Once the internal pressure reaches as much as seven times the outside pressure, the outer layer can no longer withstand the build up and gives way. The kernel breaks open… and pops!

Because of the sudden drop in outside pressure, the inside immediately expands to fill the space, puffing up into delicious, fluffy white popcorn.



There are two main types of popcorn kernel: butterfly and mushroom. Butterfly popcorn is so called because of its irregular shape and many jutting “wings”. Mushroom popcorn is rounder, larger and has a more uniform shape. Because of this, it needs a higher temperature and will usually take longer to pop.

We love both but because of its slightly larger surface area, mushroom popcorn is often favoured for sticky toppings like caramel or chocolate.

Speedier when wet

If you soak popcorn kernels in water just before you heat them, more steam will be produced and they’ll pop faster and more efficiently.

Enough science, is it good for me?

Air-popped popcorn is naturally high in fibre and antioxidants, low in calories and fat and completely free from sugar and sodium. So, in short, yes – homemade popcorn can be a great choice if you’re trying to cut down on sugary snacks, counting calories or want to help lower your cholesterol by boosting your fibre intake.

Of course, you can also go wild and make your popcorn as decadent as you like with an indulgent topping!