Resources required:
One cup of milk, 4 teaspoons of white vinegar, a bowl, a strainer and adult help. 

Description of investigation:
1. Ask your friendly adult to heat up the milk until it is hot, but not boiling.
2. Now ask the adult to carefully pour the milk into the bowl.
3. Add the vinegar to the milk and stir it up with a spoon for about a minute.
4. Now the fun part!!! Pour the milk through the strainer into the sink – careful it may be hot! Left behind in the strainer is a mass of lumpy blobs. When it is cool enough, you can rinse the blobs off in water while you press them together.
5. Now just mold it into a shape and it will harden in a few days. 

More info:
https://kids.kiddle.co/Curd

Investigation Questions:
Will  more vinegar make more casein?
Will you get the same results with low-fat milk or soy milk?
Do all types of vinegar work?
Will other acids, such as lemon juice and orange juice work?

How does it work?
Plastic? In milk? Well sort of.  You made a substance called CASEIN. It’s from the Latin word meaning “cheese”.  Casein occurs when the protein in the milk meets the acid in the vinegar.  The casein in milk does not mix with the acid and so it forms blobs. 

Skills Acquired:
Think Critically – ask questions and find out answers.
Collaborate with family members.
Get Creative! Decorate your final product.
Communicate your findings with others.

Suggested Links to other Subject areas:
Mathematics:
Learning about different shapes.
Language:
Understanding and following instructions.
Reading facts and researching about how increased acidity causes the milk proteins (casein) to tangle into solid masses, or curds.
Creative Arts:
Decorate your final product.