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Tuesday, September 27, 2022

Gelatin Brain Science Experiment

My girls are fascinated with anything jelly, so I decided to capitalise on that interest and create some scientific fun with a jello brain. This edible science experiment was so easy to put together in the kitchen with some simple ingredients. As a bonus it doesn't contain any sugar, so it doesn't matter if the kids end up tasting it.

I fully admit this is a pretty creepy looking activity, which means it's perfect to do as a Halloween science experiment and if your kids like zombies then they'll love it. It's also a great interactive way to teach children about neurological pathways and capillary action in the brain.
gelatin brain science experiment

This gelatin brain activity is a great way to combine scientific exploration and sensory play in an age appropriate way for kids. As the children are squirting blood and neurons into the brain they'll be working their fine motor skills and learning more about how the brain works. Making the gelatin brain is also a hands on way to learn about semi solids.


Making a gelatin brain is actually really easy thanks to brain moulds that can be found online. You just need to slightly adjust a normal jelly recipe with some additional gelatin, or use only gelatin and no packet jello for a sugar free version like we did. 

The brain will need to set for a few hours so it's best to prepare it the night before you want to use it. Follow the supply list and instructions below.

  • Water
  • Gelatin
  • Food Colouring {optional}
  • Brain mould
  • Small bowl
  • Spoon
  • Jug

1. Place the brain mould upside down inside the bowl so it's sitting level. The bowl will help to keep the mould in place once it's full.

gelatin brain mould in bowl

2. In the jug make up water and gelatin mixture with 2x as much gelatin as is recommended on the packet. Once the gelatin has dissolved into the water, pour it into the brain mould. We made ours in 500ml lots and the brain mould took 1500ml in total. You'll need warm water for the gelatin to dissolve properly, but don't use boiling water as it could damage the mould.

pouring gelatin and water mixture into brain mould

3. Add a drop or 2 of food colouring to the mould and stir until it's dispersed. This step is optional, you can always keep it clear if you want to see the liquid squirting through it easier during the experiment.

adding food colouring to mixture

I only wanted to add a drop or two, but of course a heap poured out by accident, so our brain turned out a lot more red than I was wanting. Squeeze top food colouring is much better for this step, or use a pipette.

4. Carefully move the bowl and mould to the fridge and allow to cool and set overnight. We lined the fridge shelf with paper towel under the bowl in case it leaked.

gelatin brain setting in fridge


The concept behind this is experiment is for children to squirt blue neurons and red blood into the brain using dyed water in pipettes. So you will need a few other items such as red and blue food colouring, plastic pipettes, non spill cups for the food colouring and a large tray to complete the experiment on. You may also want to use an art smock or plastic tablecloth as it can get messy after a while.

The easiest way to get the gelatin brain out of the mould is to sit the tray upside down on top of it and then flip it so the brain mould is sitting on top of the tray then loosely remove the mould so it doesn't cause any breakage. 

*If you think the mould is set too firm then fill the bowl the brain mould is in with warm water and let the mould sit in there for a minute before putting it on the tray.

gelatin brain experiment set up on tray

Set the dyed water up next to the gelatin brain with a pipette in each colour. Ideally you will have both blue and red water, however because our brain turned out much darker red than I anticipated {was hoping for light pink} we decided to just use the blood as it would be really hard to see the colours go through the brain.

pipette of red water to squirt into gelatin brain

While our brain didn't work out exactly as we wanted it to, the girls still had lots of fun squirting the blood through the brain. It was also a great fine motor work out while they squeezed the pipettes to suck up and release the water. The more water they squirt through the brain, the more likely it is that it will start to split or break apart as it weakens the gelatin.

squirting red water into gelatin brain

Even though our experiment didn't go entirely as planned the girls still had a great time exploring the jelly brain and then deconstructing it in the end. You can add a spoon and plastic knife for the kids to dissect the brain once they're done squirting the coloured water into it.

Word of warning though, once they start dissecting it, and especially if they eat some of it, it can look a little too realistic {especially if your brain is pink or red}. I was almost gagging watching them, which of course meant it was even more fun for them.

kids dissecting gelatin brain

We will definitely be doing this experiment again with a transparent gelatin brain and blue and red water. I'll add updated pics when we do.


The gelatin brain science experiment teaches elements of chemistry and biology in a hands-on, interactive and age appropriate way to young children. 

Gelatin chemistry explained

Making the gelatin brain shows how chemistry works by witnessing how gelatin changes under different conditions. Gelatin is a biopolymer {a protein found in living organisms} which is a semi sold and can exist both as a solid or a liquid. 

Gelatin powder starts out as a solid which is made up of many hundreds of amino acid strings that are bonded together, however once it's heated up in water the amino acid strings start to loosen apart and the gelatin turns into a liquid. As the water and gelatin mixture cools in the fridge the amino acid strings bond back together trapping the water and forming a solid. Eating gelatin warms it up again and dissolves it back into a liquid state.

how gelatin changes from solid to liquid to solid

Brain biology for kids

Squirting red and blue liquid into the gelatin brain visually shows children how neurons and blood travel through the capillary systems in the brain demonstrating cerebral circulation and neurological pathways. This experiment is a simple way to show younger children how the brain works.

how to make a gelatin brain

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