I have been trying to do more kitchen science experiments because all of my charge’s love science-based activities.  We have made casein plastic before using milk and vinegar, but this time we made bio plastic using gelatine.

Make sure you follow my science board on Pinterest for more ideas.  Don’t forget to save the pin for later.

To make your own bio plastic you will need:

  • 3 packets of gelatine*
  • Food colouring ?optional?
  • Moulds
  • Saucepan

*We used both packs of gelatine and gelatine leaf.  4 leaves are the same as one 12g packet.

Start by measuring 75mls of water and mixing in the gelatine and add any food colouring you may want.

how to make a bio plastic

Heat it over a low heat until it starts to thicken and steam.

Before adding it to the pans, try to scrape any foam that has formed off from the top.  The more your get off, the clearer your finished products will be.

how to make a bio plastic

Add the mixture you your moulds and leave them too completely dry.  Their drying time will depend on how think they are.  The thicker they are, the longer it will take to dry.

Top Tips

If you want to add two colours into one mould, then you will need to prepare two colours at the same time.  The longer you leave it between adding another colour, the less they will mix.  We had about a 5-minute wait between adding the next colour, and they didn’t mix at all.  We just have two layers of different colours.

Don’t try to take the pieces out of their moulds for at least 24hours.  If you do, they may tear.

At first, they will feel like firm gummi sweets, but after they have completely cured, they will be rock hard.  The thinner pieces may curl when dried.

It may take up to 5 days to completely dry.

I have already been asked if we can make them again and try turning them into something else.  Plus, it has led to some really interesting questions about why we can’t use this type of plastic in more items.  The simple answer is it will dissolve in water and melt under heat.

If you enjoyed making these bio plastics, be sure to check out how to make casein plastic.

Pin for later:

How to make bio plastics using gelatine.  Kids STEAM experiment