Did you know that you can make your own plastic out of milk and vinegar??
For his 10th birthday, Aidan received the book Sneaky Uses for Everyday Things (affiliate link) from one of his friends. It’s a pretty awesome book. The book contains 42 different inventions to make out of household materials such as a homemade battery, an electronic greeting card, and a makeshift telescope. Aidan was really intrigued by the page on how to make plastic out of milk and vinegar. I stalled for several days on this one because it sounded messy and smelly, but we finally did the project and wow! It was easy to do and SO much fun!
To make plastic, you will need:
- 1 cup of milk
- 1 Tablespoon of vinegar
- A small pan
- A spoon
- A strainer
- Paper towels
- Food coloring (optional)
First, put one cup of milk in a pan and heat it until warm. It doesn’t need to boil – just be warm.
When the milk is warm, stir in 1 T of vinegar. The vinegar will cause the milk to quickly separate into curds and whey. The acid in the vinegar causes the protein strands in the milk to coagulate. The curds are casein, which is used in the production of glue and some plastics. Who knew?
Pour the contents of the pan into a strainer. Use a spoon to squish out the extra liquid.
Knead your plastic with your hands and use a paper towel to dry off any excess moisture.
Then mold your plastic into whatever shape you want! It’s a little tricky to mold because it has a texture sort of like ricotta cheese (which is probably what it is?). We flattened it out and used a measuring spoon to cut out circle shapes for key chains.
We also made a second batch and added a few drops of blue food coloring to the milk before heating.
Let your creations dry for 48 hours or more. I had my doubts about this stuff becoming anything that resembled plastic, but it worked!!! We found that smaller, thinner shapes dried better and faster. The blue color dried darker than it looked when it was wet.
We used straws to make holes for the key chains before they dried. Our holes shrank as they dried, so beware! They were barely big enough to be key chains once they dried.
You can paint your plastic to decorate it however you want. We used acrylic paint.
What else can you do with homemade plastic?
- Use cookie cutters to cut out shapes
- Make magnets for the refrigerator
- Make playing pieces for a board game
For more crazy science fun, check out our exploding chain reaction made with craft sticks!