Plastic Milk for Mad Scientist Monday

This is a really cool experiment I found from Science Bob's website. I haven't actually tried it yet, but I'm going to. It's not really plastic that's made. It's actually CASEIN that's formed when the protein in milk meets with the vinegar.

Ingredients:
1. 1 cup of milk
2. 4 tsp. white vinegar
3. pot for heating
4. strainer
5. bowl
6. spoon

Procedure:
1. Heat the milk until it's hot (not boiling)
2. Pour the hot milk into a bowl.
3. Stir in the vinegar for about a minute.

Google source

You can see the casein starting to form in the pic above.

4. Pour the milk through the strainer into a sink.
5. You'll be left with lots of goopy white lumps in the strainer.

Google source

6. Rinse the blobs in cool water.

7. When it's cool enough to handle you can press the blobs together and mold them into shapes using cookie cutters.

8. The moulded shapes take a couple of days to harden and they can also be painted.

As you know, I also like to do whole class hypotheses before beginning and I like to glue the kids' predictions on chart paper. For this experiment I would give everyone a paper milk carton to colour and put their name on. Each child would then glue theirs above the appropriate hypothesis.