Observations and results
Were you able to see the curds when the hot milk and vinegar were mixed together, and could you scoop out the curds to make casein plastic?

After you add the hot milk to the vinegar, small, white chunks—or curds—should become visible in the mixture. This is because adding an acid (such as vinegar) to the milk changes the latter's pH (acidity) and makes the casein molecules unfold and reorganize into a long chain, thereby curdling the milk. You should be able to use a spoon to separate the curds from most of the liquid. Additional drying of the curds with the paper towels should make the curds ready to knead into a ball and use as casein plastic, which can be molded and decorated.

More to explore
Polymer Basics from Polymer Science Learning Center, Department of Polymer Science, the University of Southern Mississippi
Casein from Plastics Historical Society
Welcome to the Caseino: A virtual museum devoted to casein plastics from John Morgan
Turn Milk into Plastic! from Science Buddies

This activity brought to you in partnership with Science Buddies

6 Comments

1. 1. Greenberet 10:59 PM 9/14/12

   I would like to have to try!

   Reply | Report Abuse | Link to this

2. 2. Quentin 06:21 AM 9/16/12

   This article brings me the greatest relief. Around about 1939 my father appeared wearing dark ringed spectacles. He told me that they were made out of milk.
   Being age 5 I naturally believed this magic. But I grew to doubt my father as commonsense took over. He died in 1974.
   I now wee that he was right. I am sure that he will be dancing in Heaven

   Reply | Report Abuse | Link to this

3. 3. Quentin 06:22 AM 9/16/12

   No, I didn't mean "I now wee"

   Reply | Report Abuse | Link to this

4. 4. lughaidh 11:46 AM 9/27/12

   This is great,
   
   it's also actually a recipe for how to make an Indian cheese called Paneer - a staple source of protein in our house. I never knew that I've been eating a plastic for my dinner over the last thirty years.

   Reply | Report Abuse | Link to this

5. 5. Luke Cage in reply to mistryafzal 07:12 PM 5/2/13

   Sorry buddy but Allah is a demon. Islam is a false faith and Muhammed was a pedophile, liar, hypocrite, raider, murderer and claimed to be possessed by demons.

   Reply | Report Abuse | Link to this

6. 6. Quentin 04:44 AM 5/3/13

   In 1939 he was the editor of the Catholic Herald -- the leading Catholic paper in England. So I imagine he would have agree that there was no God but Allah. But of course he would have used the word God -- in the Christian way.

   Reply | Report Abuse | Link to this