My 6 year old came out of school last week incredibly happy and excited as they’d spent the afternoon building candy houses. As soon as we got home he wrote me a shopping list of what we needed to do a similar activity at home. This would also be great for a Three Little Pigs experiment or Charlie and the Chocolate Factory themed investigation.
We talked about what we wanted to achieve and decided to split our project into 2 stages, building on the knowledge he’d gained already from school.
If you like this activity, I’ve got 60 more easy edible experiments in my new book – Snackable Science

Candy House STEM Challenge
What are the best sweets for ‘bricks’?
We decided marshmallows were too soft and not the best shape, but fudge rectangles would be perfect.
What can we use for ‘cement’?
Z said it needed to be sticky and harden over time, so we thought we’d try very thick icing sugar and marshmallow fluff.
How can we test?
We didn’t want to waste too much fudge in our testing ( although it did all get eaten ) so we decided to build two small walls to test our ‘cement’.
We discussed what we needed to keep constant and what needed to change.
Variables
- Icing
- Marshmallow Fluff
Constants
- The amount of fudge.
- The amount of ‘cement’.
- Time left to harden
We used the same number of fudge pieces for each wall and tried to roughly use the same thickness of ‘cement’, but this wasn’t entirely accurate.
Both walls were left overnight to harden.
How to test for stability/strength?
- Pick up the wall and see if it stays intact.
2. Roll a marble to the wall – try to roll at the same speed and in the same direction for each wall.

Candy House Results
Observations
The icing sugar hardened completely, while the marshmallow fluff stayed soft and sticky.
Marble Test
The icing sugar wall fell over.
The marshmallow fluff wall stayed upright, but possibly because it was so sticky, the marble stuck to it, losing some of its momentum.
The pick-up test
The icing sugar wall remained in one solid piece when picked up.
The marshmallow fluff wall fell to pieces.
How can we improve this test?
Neater application of the marshmallow fluff so the outside of the wall was less sticky.
Place both walls in the fridge overnight to encourage the setting of the marshmallow fluff.
Next steps
Build a complete house, finding a suitable material for roof tiles.

Suitable for Key Stage 1 Science
Brilliant for starting to learn investigative skills.
Extension tasks
Can you make a stable structure? What can you use to support the roof of your house?
Making a gingerbread house and testing that for strength is a fun variation on this activity too.


Last Updated on April 25, 2023 by Emma Vanstone
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