- Source of heat: microwaves, stove.
- Elastic bands
- Non-metal 250ml cups or beakers. Don't use plastic in a stove.
- Wooden sticks or spoon to stir
- Small measuring jug
- 150ml milk
- 15ml vinegar
- Measure out 150ml of milk into a beaker and heat on a hotplate or stove.
- When simmering, take off/turn off heat and add 15ml of vinegar to the milk.
- Stir for a few minutes. The mixture will separate out into a liquid and a solid known as “curds and whey”. Leave to cool for a few minutes - Use elastic bands to secure the cheesecloth over the top of the other beaker allowing for a dip in the middle rather than stretched tight. - Pour mixture through the cheesecloth to filter off the solid from the liquid. This can be quite slow.
- Gather up the solid in the linen and squeeze off as much liquid as possible.
- Pat the solid as dry as possible with some tissue.
- Squash it together and mould it.
- Leave it for a few days to dry out.
As I moulded it in the shape of a small bowl, when dried, I did paint it with on the inside and Gold leaf paint on the outside.
Remember, you are now are left with a tough but brittle plastic.
What you have just made is called Casein plastic. Casein is a type of protein that can be found in cow's milk, and makes up up to 80% of it.
Casein molecules are monomers. When we add vinegar to the milk, it changes the pH of the milk and makes the casein molecules to reorganise forming long chains and therefore, polymers. When we dry up the dough, the molecules interlock achieving a hard plastic.