Blogger / 10 February, 2026 / Nanny Anita

Frozen Fizzing Hearts

This frozen fizzing heart activity is a variation of the classic vinegar and bicarbonate of soda experiment.  These sorts of activities always go down well with children because of the fizzing nature of it.  Plus, I thought it was about time to introduce NC to some science-based fun.

Make sure you follow my Valentines Board on Pinterest for more ideas.  Don’t forget to save the pin for later.

To make your own frozen fizzing hearts you will need:

• Bicarbonate of soda
• Water
• Food colouring
• Heart moulds
• Tray
• Pipettes
• Vinegar
• Bowl

To make the frozen hearts you first need to make a past with bicarbonate of soda and water.  I used about 3 tbsp of bicarb, then mixed in some coloured water until it became a paste.

When it has reached the desired consistency spoon it into the moulds and press down firmly.  Next put it into the freezer.  I left ours in there for 24 hours, but I am sure you could leave them in there for less time.

When you are ready to use them take them out of the moulds and pop them into a tray with some vinegar in a bowl and a pipette.

NC loved this activity; she spent about 25 minutes playing with it.  Even when all the hearts had mostly dissolved and stopped fizzing, she enjoyed using the pipette to play with the leftover mix.

If you enjoyed these frozen fizzing hearts, be sure to check out my homemade chocolate hearts and loo roll heart stamping craft.

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