Mystical Milk

For a while now my youngest has been asking me to do the “milk experiment” so this week we finally got round to it.

I really enjoy simple experiments that are full of colour. They are visually awesome and my kids tend to remember them.

If you want to give this experiment a try then the following is a list of what you will need.

You may notice from the picture that we initially used food colouring and semi skimmed milk for this experiment. Through trial and error we realised that the gel colour was way too thick and the full fat milk gave better results. I had liquid watercolours in my materials stash so we gave these a try instead and they worked so much better. 🙂
First of all we poured the milk into the dish/plate.
This is what happened when we used the gel colours – they sank and were too heavy to properly react.
This is what happened with the gels. There are some pretty patterns but it was slow, and not all the colour mixed.
This was the end result – it took a lot of forced mixing with cotton buds which isn’t the point of the experiment really! Pretty, but not what we wanted.
TAKE 2 – this is the liquid watercolour and I think you’ll agree that it looks GORGEOUS!
Once you have put all the colour you want into the milk you need to take a cotton wool ball and generously dip it into the washing up liquid. You then place it into the middle of the plate/tray and watch what happens. The colour will be pushed to the sides and will start to swirl to make pretty patterns. The colours ended up a bit muddy but we still loved how it looked.
TAKE 3 – we decided to use less colour to see what the results would be like.
The patterns we stunning again! 🙂

We made a little video to demonstrate what happens when the cotton wool ball is placed into the milk…. please watch if you have 47 seconds extra of spare time – we think the results were amazing!


Despite the fact that some of these experiments are simple, I always love to explain the science behind them. Milk is mostly made up of water but depending on what type of milk you buy, there is also a lot of fat. When you put the washing up liquid into the milk, it bonds with the fat and, therefore, pushes the water and colour out to the sides. The molecules attack the fat in the milk which creates the swirling of the colours.

We did lots of versions of this experiment. My youngest was very disappointed when the first one wasn’t that exciting but in true STEAM Powered style, we kept on trying and found a way that worked for us.

Hope you HAVE FUN!!!

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