Foam Eruptions Recipe

An excerpt from the recently released, new edition of "Recipes For Messy Play".

This is a great science experiment with the ‘wow factor’. The baking soda reacts with the lemon juice/citric acid releasing carbon-dioxide as a by-product. The bubbly gas released produces super foam from the hand soap. The super foam is then cold to the touch – do you know why?

INGREDIENTS:

• ¼ cup Clear liquid hand soap
• ¾ cup Warm water
• 2 Tbsp Baking soda
• 2 Tbsp Citric acid, or lemon juice (try using both and experimenting to see what works best)
• Food colouring

METHOD:

Set out small containers in a deep basin or water trough. Add clear hand soap and warm water to each container and invite the children to mix to create soapy water. Add a few drops of food colouring to each one.

Invite children to add spoonfuls of baking soda to each bowl of soapy water and mix it in – it should become gooey. The children can then add spoonfuls of citric acid (or lemon juice). As soon as the citric acid/lemon juice hits the baking soda/soapy water combination, it will create a very light, airy, fluffy foam.

Set out small spoons or sticks for mixing. The more the children mix in the citric acid, the lighter, fluffier and bigger foam they’ll get!

Tip out all of the containers into a large container – get stuck in with hands and mix for some extra foamy fun!

Looking for more recipes?
The new edition of Recipes for Messy Play is available now.

This book is a collaboration between New Shoots Publishing and New Zealand Teritary College, a revised edition of the original Playcentre publication.