Fizzing Baking Soda Eruptions

A tray of coloured bicarb and a pipette of vinegar. Endlessly repeatable fizz.

Ages 3–7Prep 5 min · Activity 25 minSome messIndoor or outdoorSensory PlayEasy

By WonderCraft Kids Editorial Team, Editorial team · Updated 13 August 2026

Forget the papier-mâché volcano. Spread bicarb in a tray, hide colour in it, and hand over a pipette of vinegar. The eruptions are small, controllable and repeatable forty times, which is what children actually want.

What you need

A cup of bicarbonate of soda
White vinegar in a jug
Pipettes or a small squeezy bottle
Food colouring or liquid watercolour
A deep-sided baking tray
Small cups for coloured vinegar

Step by step

1
Spread the bicarb in an even layer across the tray.
2
Mix three cups of vinegar, each with a different colour.
3
Give your child a pipette and show them one squeeze.
4
Let them fizz wherever they like — the colours spread and blend as they react.
5
Talk about what the bubbles are made of while it happens.
6
Top up with more bicarb when the fizz slows.

What kids learn

Chemical reactions

An acid and a base producing carbon dioxide gas — the bubbles are the evidence, right there.

Fine motor

Pipette squeezing is targeted finger-strength work disguised as the best part of the activity.

Colour blending

Foam carries colour sideways, so blends appear that paint on paper would never show.

Make it easier

One colour and a spoon instead of a pipette. Big, instant, satisfying fizz.

Make it more challenging

Ask them to make the biggest single eruption possible, and test whether more bicarb or more vinegar does it.

Safety and supervision

Vinegar stings eyes. Eye level away from the tray, and rinse immediately if it splashes.
Use white vinegar only — malt and balsamic stain badly.
Do not seal the reaction in a closed bottle; gas pressure builds fast.

Adult supervision is required for every activity on this site. Read our full child safety guidelines.

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