It's time to excavate!

It's time to excavate!

It’s time to excavate

This weeks #steammsunday has got to be the dinosaur excavation.

It was a real divider, some children weren’t on board with the activity and some definitely were! That’s the beauty of The Fern Club; giving children the opportunity to make their own opinions and explore at their own pace.

This activity was a great STEAM (science, technology, engineering, art and maths) experience. Drawing from the science element the reactions between the bicarbonate of soda and lemon juice the children were able to see the fizzing and bubbling in action.


If you’re happy to experience and experiment at home, take a look below at how I approached this and what you and your little one can learn from it.





Used coffee grinds – Starbucks/Waitrose give these away for free if you don’t have access to them at home… or come ask me. With a 10 month old nap-avoiding, teething monster, early walker we get through a truck load of coffee!

  • Coffee beans – to add some more texture. Could use any kind of dried bean.
  • Bicarbonate of soda
  • Lemon juice – I believe vinegar would create more of a reaction. I couldn’t quite face the vinegar/coffee bean aroma in the halls this week.
  • Flour
  • A large box
  • A wipe clean mat
  • Little dishes for the lemon juice
  • Pipettes or small spoons – you want something which will only transfer a little at a time to begin with, build the excitement and create a sense of wonder. You can dump the lemon juice onto the mixture later in the exploration so start small to draw out the investigation a little longer.
  • Small plastic dinosaur toys



I started by creating little balls of the coffee grind, flour, bicarb mixture. Stick a little together with a little water and roll up. The larger the ball, the less fizz and longer it took to react. (A massive thank you to the wonderful Monday class who were incredibly patient when trying this for the first time, it did take a very long time with the larger balls) I did put a small dinosaur toy into the middle of the ball but on reflection it wasn’t necessary. The children were happy to play with the dinosaurs whilst watching and making the fizz.


Once I’d created 4-5 of the balls I laid them onto a bed of coffee beans, coffee grinds a little flour and a LOT of bicarb. The bicarb is the key to this so the trick is to use as much as you can. Mix it all together so it makes the appearance of “mud”.


Place the little dish into the middle of the mud and fill with lemon juice. Then play! Drop small amounts of the lemon juice onto the mud and let the little ones lead the way. A great way to extend this is to tell a story, or make observations about what you see.




If your little one is at an age where they’re beginning to understand more scientific explanations this is what’s happening…


When you mix the bicarbonate of soda, (an alkaline base) with the lemon juice, (an acid) the chemical reaction (the fizz) creates a new substance.

Carbon dioxide, water and salt!


This activity can really be explored in so many different ways! The possibilities are really endless so when you’re happy to delve in further, take to google and see what else you’re able to concoct.

When I was little my scientist Grandad and Dad used to show us so many different experiments, the one which was always a crowd pleaser was so simple. If you want to try it at home, please please let me know, I’d love to see the pictures and hear all about it….


1 x old camera film case


Bicarbonate of soda


Head outside, put a spoon of bicarb into the case, add a spoon of vinegar, QUICKLY put on the lid, leave on the floor and step back…. The little explosion is perfect for children.


Have a great week exploring and playing. Be sure to tag me in any of your Sunday activities #steammsunday


Have fun!  

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