Try this fun, hands-on experiment to learn about surface tension, water molecules, and basic chemistry… all while making GIANT bubbles!

What you need:

• 2 cups of water

• 1/2 heaped teaspoon baking powder

• 1/4 heaped teaspoon guar gum powder (we got ours from New World)

• 3 and 1/2 tablespoons dishwashing liquid

• 1/2 cup glycerine

• A jar or container with a lid, to store your mixture in.

Note: If you don’t have access to the items you need to make a giant bubble wand (see below), try making our smaller homemade bubble wands here…

How to make the bubble mixture:

1. Add the guar gum to the glycerine and stir until combined.
   Mixing the guar gum with glycerin will prevent it from clumping.
   If you add it directly to water, the guar gum will become a gel and will not mix properly with the water.

2. Add the guar gum mix to the water and stir.

3. Leave the water and guar gum mix to rest for 10 minutes.

4. Slowly add the dishwashing liquid and stir gently.
   Note: don’t stir too quickly, or for too long, or the mixture will start to bubble and be less effective at creating bubbles.

5. Add the baking powder and stir gently to combine.

6. Leave the mixture to rest for at least 24 hours. However, 5 days will get the best results.

7. To make giant bubbles, you will need a giant bubble wand.

How to make a giant bubble wand:

1. You will need 2 wooden dowel rods (these should be at least 150cm long), two eye screws, one washer, 1-metre length of string or wool and a 1.2-metre length of string or wool.

2. Screw an eye screw to the top of each dowel rod.

3. Thread the 1.2-metre length of wool through one washer.

4. Next, tie each end of the 1.2-metre length of wool to the eye screw at the top of each dowel rod.

5. Thread the 1-metre length of wool through the two eye screws and secure with a knot.

How to make giant bubbles:

1. Hold your dowel rods on the ends without the eye screws.

2. Gently touch the two eye screws together and dip the wool into the bubble solution.

3. Slowly lift your wand out of the bubble solution, keeping the two rod ends together.

4. Hold the bubble wand away from your body. Slowly separate the ends of the rods to open the wool loop in your giant bubble wand and walk against the wind.

5. Watch as a giant bubble begins to form and slowly move the ends of your rods together again to close and release the bubble. If you don’t move the rods together again, the bubble will burst.

Experiments to try:

• Try using different lengths of wool and see how it changes the size and type of bubbles you create. Is it easier or more difficult to create bubbles using longer lengths of wool?

• Use a tape measure and chalk to draw a giant ruler on the ground, then measure how long the biggest bubble was that you created.

• Try changing the bubble recipe to see how it affect the bubbles you make. Does adding more water, dishwashing liquid or removing baking powder make a difference?

• Try changing the type of dishwashing liquid you use. Do different brands make better bubbles?

What we learn:

• Guar gum is a thickener and emulsifier that keeps your bubble mixture combined. It keeps your bubble ingredients from separating.

• Bubbles hold their shape because of surface tension. The bubbles you create are made up of three very thin layers: dishwashing liquid, water and another layer of dishwashing liquid. It is the water layer that holds the bubble together. When the water between the two dishwashing liquid layers evaporates, the bubble pops.

• To make your bubbles last longer, the bubble recipe above uses glycerin and guar gum to thicken the dishwashing liquid layers and slows the water evaporation.

• Large bubbles have a large surface area. This creates more places for air pressure or gravity to affect the bubble. Larger bubbles also have more weight to support, which is why bubble that are too large are more likely to collapse and pop quickly.