The history of instant noodles and the science of diffusion

AQUILA Magazine is here with a blog all about instant noodles. A whole blog about NOODLES? Why? Because we all know that they taste great but did you know those delicious little worms of dough (erm, you’re not making them sound that appetising) can be used for science too! 

According to a survey by the Fuji Research Institute, the Japanese believe that, of all the things they invented in the 20th century (including Mario?), instant noodles is the best. Often known simply as ramen, they first appeared in 1958, and now over one hundred BILLION (100,000,000,000) portions are eaten around the world each year!


When you cook dried noodles, you are not only heating them up. You are making water travel into them too. This process is called diffusion and you’ve met it many times before. It’s happening when you open your front door and can instantly detect delicious smells coming from the kitchen…or when you get a whiff of your dog’s trump from all the way across the living room.

Diffusion happens when molecules move from a place of high concentration (where there are lots of them), to a place of lower concentration (where there are fewer). Diffusion happens faster in hot air or hot water because the molecules have more energy and move around more.  

When you cook a noodle, the water diffuses from the outside (where there is lots) to the inside (where there is less). As it does so, the water makes the starches swell up and become soft. The quicker the noodle takes up water, the faster it will cook. This is really important for instant noodles!

You need to get your timing right though. Too little time means the centre of the noodle will be hard. Too much time means your noodles become too soft and break into little pieces. (Yuck, I hate that, ed.) Exactly, no use for slurping at all!

What makes instant noodles… instant?

Instant noodles have been very carefully engineered to give super-speedy wriggly results. 

A mixture of wheat flour and potato starch is used because these starches can rehydrate (get wet again) and become soft very quickly. The dough also contains water and a special alkaline salt called kansui. This makes the noodles more springy. It also helps to give them that characteristic yellow colour. Other ingredients are added to improve water uptake and shorten cooking time further.

The dough is mixed, rested and kneaded to make it smooth and stretchy. It is then rolled out and folded several times to further develop the gluten (the protein responsible for the stretchiness). 

Next, the dough is rolled to a thin sheet, placed on top of another sheet and passed through a series of rollers to get the right thickness. 

Next, the sheet of dough enters the cutting machine where it is sliced into long noodle strips. As the noodles leave the machine, they go past swinging weighted flaps. As they are grabbed and released, they slow down, then speed up, helping to create the squashed loops that make instant noodles so curly. 

The noodles are then steamed. This makes them absorb more water so the starches gelatinise (become like jelly) as they break down permanently. 

Healthy instant noodles are dried in hot air, but most instant noodles are dried by frying in hot oil (yes, you read that correctly). In both processes, the water evaporates quickly, leaving lots of tiny pores inside the noodles; they basically become like little sponges. These holes let the water in quickly when you cook them.

The dried noodles are then cooled and packed up with a seasoning sachet, ready for shipping to the shops.


You will need:

– Instant noodles

– 2 small bowls

– Boiling water (plus helpful adult!)

– Cold water

– Fork or chopsticks

– Timer

Step 1:

Break two pieces off your noodle block – this is difficult, so don’t worry if they are not equal in size. Place one section into each bowl.

Step 2:

Cover the noodles in one bowl with cold water, and the other one with boiling water. They will float! Why? Start your timer.

Step 3:

Can you see anything happening? Look for tiny bubbles of air escaping as they are replaced by water. Can you see tiny puddles of the drying oil floating on the surface? Do the noodles in one bowl look fatter than in the other? Why?

Step 4:

Remove and test a few noodles from each bowl at 1 minute intervals.

Step 5:

How long does it take for the noodles to become soft? The noodles from both bowls will become soft because the sponge-like texture of the noodles improves diffusion. We know that diffusion happens faster in hot water because the water molecules are moving more. So you should find the noodles go soft faster in the hot water than the cold. But wait long enough, and even the noodles in the cold water will be ‘cooked’!

Step 6:

Repeat the experiment and add some of the flavour sachet (or a few drops of soy sauce) to each bowl. Do not stir it in! Does the colour spread faster in one bowl than the other? Can you work out why?

Step 7:

Repeat the experiment with regular (not instant) noodles. Do the noodles still go soft? Can you work out why?

Step 8:

Once you’ve finished experimenting use the rest of the noodles for your lunch!

If you’ve enjoyed this and want more fun facts, super science with the odd LOL along the way then sign up for the brilliant AQUILA magazine today! 

Words: Sarah Bearchell. Illustration: Kaley McKean