Hopalong: FOUNDATION - Science- Explain

When B-Boy comes to stay overnight, Little J becomes envious of the attention he is getting from everyone. Out walking on Country, Nanna, Little J, Big Cuz and B-Boy find an injured joey. Uncle Mick, a Search and Rescue officer, tells them how to care for the joey that they name ‘Hopalong’. The children feed and look after Hopalong until Mick finds him a place in a wildlife shelter.

Explain - Engage in discussions about observations and represent ideas

Theme - FAUNA

As a class, revisit Little J’s story within episode 7, ‘Hopalong’, and ask students to recall what type of animal Hopalong was and how the family rescued and cared for it.

As a class, revisit the reasons why Hopalong was lost. Have students pose questions about how Hopalong would feel both physically (thirsty, hungry, hot, etc.) and emotionally (afraid, anxious, lost, etc.) Discuss what would have happened to Hopalong if he hadn’t been found by Little J and the others. Have students hypothesise what would happen to him, and all living things if they didn’t have food and water.

Have students identify what sustenance (including food and water) living things need to survive. Have students estimate how long living things can go without essential food and water. Discuss how we know if a living thing is alive or dead.

Conduct the following Science experiment.

Testing yeast – living or dead

Inquiry question: Is our food alive or dead?

Equipment & materials

  • two small bottles
  • a funnel
  • two balloons
  • instant yeast in 2 sachets or in a tub (make sure it is not out of date)
  • a small sachet of sugar
  • a measuring spoon
  • a small jug of warm water
  • two sticky labels: one reading ‘Food’ and one reading ‘Not food’

Step 1:

1. Start by exploring students’ thoughts about food. Ask questions such as:

  • Who likes to eat food?
  • What type of foods do you like to eat?
  • Do all living things need to eat food?
  • Do all living things eat the same foods?

2. Have students determine that all animals and living things eat foods, even if they eat different things.

3. Go further and have students consider the following questions:

  • How do we know if a living thing is alive? (breathing)
  • Does a living thing grow, move, and breathe if it is alive?

4. Have students determine that living things need water, air, warmth/sunlight and food.

Step 2:

  1. Introduce the instant yeast to students. Put a pinch in a bowl and let students sniff and touch it. Ask questions to the class:
    • What does it smell like?
    • Is it alive?
  2. Does it eat, move, grow, or breathe?
  3. Suggest that it may be sleeping. Add some water and let students smell it again. Ask them to observe what has changed about the yeast after introducing the water?

Step 3:

  • Using the funnel, measure a sachet of dry yeast (or one large spoonful) in each bottle.
  • Pour warm water into each of the small bottles until they are about ¾ full.
  • Into one of the bottles, add the sachet of sugar, put on the lid (or put your thumb over the top) and shake the bottle gently to dissolve the sugar.
  • Label this bottle with the label that says ‘Food’, explaining that sugar is a carbohydrate and yeast loves to eat carbohydrates.
  • Do not add sugar to the other bottle. Label this other bottle ‘No food’.

Step 4:

  1. Explain how we know that yeast is alive if it grows and breathes. Yeast is so small that it will be hard to see if it has grown right away but we have a way to know it has started.
  2. Carefully put a balloon over the top of each bottle (remove any lids first).
  3. Place the bottles to one side where they can be seen by the class.
  4. Explain that when the yeast starts to breathe and grow, the balloon on top will stand up (note: the balloon will not inflate a lot, the yeast will not build up enough pressure to expand the walls of the balloon.)
  5. Leave the experiment to ferment. Ask students to observe the changes in the size of the balloons over a period of time: 1 hour, 2–3 hours and overnight.

Step 5:

1. Observations to be made:

  • The yeast in the ‘Food’ jar is expelling carbon dioxide which is being collected in the balloon
  •  The balloon on the ‘No food’ bottle will not stand up at all.

2. As a class, discuss and decide if the yeast is alive? Does it breathe and grow when we give it food/water/sugar? Or is it dead?

Teacher tips:

What’s happening in the experiment?

The yeast with food (sugar) can reproduce and increases in volume dramatically. Each of the yeasts gives off a tiny amount of gas and eventually this lifts the balloon.

While the class is waiting for the experiment to rise, investigate how to make bread and damper. Yeast is an ingredient in bread. It expands inside the dough in the same way as it did in the bottle experiment and this makes tiny bubbles that make it soft and puffy when it is cooked. Examine a slice of bread and look for the tiny bubbles made by yeast. Damper is like bread but the rising is usually by chemicals (baking powder or sodium bicarbonate) in the flour. Both create a soft and chewy bread.

View Episode 7 ‘Hopalong’ again and ask students:

  • Who makes damper in this episode?
  • Who is it for?


As a class, make a simple yeast bread. In the link below is a recipe that students could mix and observe the yeast puffing up. An adult should take the loaf and place it in an oven to bake:

  • Bread in four easy steps
    Note: If someone in the community has a sourdough starter, the class can look after a jar of starter for a week, feeding it every morning and observing the changes as it metabolises into flour and water.

Access information on making damper in the traditional way/s: