Last year, we visited the Eden Project in Cornwall, where they had a wonderful Room on the Broom tent full of fun witchy activities. My girls loved making potions full of brightly coloured glitter and lovely smelling herbs.
Back at home, my 5-year-old wanted to add water to make a proper potion, but before we did that, we tried some filtering to separate the herbs from the glitter.
Filtering Potions – STEM Challenge
What you need to filter potions
Bowls
Different sized sieves and colanders
A mixture of some kind ( use your imagination – herbs and edible glitter are great to try )
How to filter potions
Look at your mixture and think about the size sieve or colander you will need to separate it. The filtering could be a multi-step process where the larger bits are filtered with a colander and then the small bits with a sieve.
Pour the mixture through the sieve with the biggest holes. Does any separation occur?
Try again with the smaller sieves until you’ve separated your mixture.
Add some water to your lovely herbs to make a delicious smelling potion!
What is a filter?
Filter – a filter is something used to separate insoluble substances from a liquid.
More Separating/Filtering Experiments for Kids
Filter water using sand and stones, to make the water visibly cleaner. Kitchen roll/towel is another good filter.
How about making your own filters to separate a mixture of toys?
Can you make your own mixtures?
Make a fizzy or witchy potion for Halloween.
Or try some chromatography. Chromatography is another technique used to separate mixtures.
Last Updated on September 22, 2025 by Emma Vanstone
