Make ice blocks

While making ice blocks with your child, investigate volume, capacity and area. Experiment and discover just how long it takes different blocks to freeze and set — and time your icy treats to perfection everytime.

3 hours

5-6, 7-8

25 February 2021

Things you need


  • Ice block recipe
  • Ice block moulds or containers
  • Popsicle sticks



The challenge

Find an ice block recipe suitable for your child’s dietary requirements. For example, creamy mango ice blocks

Try filling differently-shaped ice block moulds with the same quantity of the recipe, for example 200ml. Does the mixture freeze quicker in some moulds than it does in others?

Another experiment you can try is to fill your identical ice block moulds with the different amount of the recipe — one completely full, one half full, one one-quarter full — and see how that changes the time they take to freeze.


The conversation

Get your child to monitor their ice blocks every 30 minutes to see which ones have set and which ones haven't. Pose these thinking questions during the investigation:

  • "How do you think the different containers will affect how your different ice blocks will freeze? Which mould do you think will freeze first? Why do you think that?"
  • "How long did it take the first ice-block to set, compared to the last one?"
  • "Do you think opening the freezer to check on your ice blocks would've made an impact to the time they took to freeze?"
  • "If we changed the temperature of the freezer, would the process be faster? How much faster, do you think? Should we test that next?"

The career

Performing experiments on temperature and volume and capacity is the daily work of professional chefs, research scientists, engineers, cosmetics chemists, food manufacturers, builders and more. If this little investigation piqued your child's interest, they might want to consider a career where they get to do it for a living.