Do your kids love science? Amaze them by making a colourful rainbow using nothing but Skittles and water! This easy candy science experiment is super simple to set up and doesn’t require any advance preparation. Such a fun activity idea for a rainy day!
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A few months back, while I was at the pharmacy, I happened to notice that Skittles were on sale. So I grabbed a bag and paid for it at the same time as my other items.
Because my five-year-old was there with me, she asked to try them that evening for dessert. And right as I was taking them out of my purse with the intention of giving some to the kids, I remembered this neat little trick and decided to give it a try.
The kids are always interested in our little science experiments, so I took out a small plate, arranged the Skittles in rainbow order and added a bit of warm water.
They were amazed at what happened—and of course, they were more than happy to eat the Skittles once the experiment was done! Because what kid wouldn’t love an activity that involves candy?
How Does the Skittle Rainbow Work?
This experiment may look like magic, but it can be easily explained by science.
The coating on Skittles is mostly made up of sugar and food colouring. For this reason, when it comes into contact with water, the sugar starts to dissolve, causing the colours to diffuse throughout the water.
The colours will eventually mix, but they initially stay separate due to water stratification. That is to say that when the coating starts to dissolve, each colour creates a water solution with a different density—and this different in water density creates a barrier that prevents the colours from mixing. (At least initially.)
Who knew that these little candies had so much to teach us?
How to Use Skittles to Make a Rainbow
Here’s what you’ll need to make a rainbow using Skittles and water:
- Skittles candy (we bought both the “Original” and “Berry” flavours in order to have all the colours of the rainbow)
- Warm water
- Small round plate
1. Sort Skittles
Start by sorting a handful or Skittles by colour. We used five each of the purple, blue, green, yellow, orange and red colours, but the quantity you need will depend on the size of your plate.
Because we wanted all the colours of the rainbow, we bought a bag of “Original” Skittles and a bag of “Berry” Skittles. The “Original” contained almost all the colours we needed, but it didn’t include blue, so we took them from the other bag instead.
2. Arrange Skittles
Arrange the Skittles in rainbow order all around the edge of the plate. The order we chose was: purple, blue, green, yellow, orange, red.
3. Add Warm Water
Slowly pour some hot water into the middle of the plate and let it spread all the way to the edge, where the Skittles are positioned. You can stop pouring when the water just covers the bottom of the plate.
4. Watch the Rainbow!
Wait a moment to see what happens. After a few seconds, you should start seeing the colours bleed out from the Skittles and spread toward the centre of the plate.
As long as you leave the plate undisturbed, the colours should stay separate until they form a rainbow that reaches all the way to the middle. So cool!
How Long Does the Skittles Rainbow Last?
It should take about 5 to 10 minutes for the rainbow swirls to reach the centre of the plate.
Once that happens, the colours may start to blend together and look a little muddy—but that’s totally fine, because as far as our kids are concerned, that’s their cue to start eating them!
How to Adapt the Skittles Rainbow
The rainbow colours make this experiment perfect for Saint Patrick’s Day, but you can also use different shape and colour variations to make this activity totally unique! In the spirit of Saint Patrick’s Day, we decided to create a Skittles shamrock:
But if it’s not Saint Patrick’s Day, you could also use Skittles to create a pink and red heart for Valentine’s Day, a flower for spring, or a pumpkin for Halloween. So many fun ideas! (Just make sure the shapes aren’t too complex or you’ll have a hard time recreating them with candy.)
Related Rainbow Activities
Looking for more fun rainbow activities to do with your kids? Check out these articles:
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