Sure, you can make a voodoo doll with plasticene, or clay, or even needle and thread. But wouldn't you think it'd have a little bit of extra-bad juju when you make it out of curdled milk?

• 4 oz. of milk
• 1 teaspoon vinegar
• small saucepan
• clean glass
• jar
• acrylic paints (optional)

1. Pour the milk in the saucepan and heat it on the stove with the flame turned down to medium. Cook the milk until it curdles, that is until it separates and gets lumpy.
   
   
2. Carefully pour out the separated liquid into the sink, leaving the lumps behind. Scoop the lumps into your clean jar and add the vinegar, then let this horrible mixture stand for about an hour, until a moldable, plastic-like blob has formed.
   
   
3. Again, pour the liquid down the drain. It's time to make your voodoo doll. Mold it and let it dry by leaving it in the air for a few hours. Then, if you want, you can paint it.  And, of course, give it a name. What else you do to this guy is, of course, up to you.

When milk curdles, the liquid separates from the "milk solids" (an ingredient you will sometimes see in food if you read the labels.) Milk solids are basically fat, minerals, and protein. The vinegar causes a "lysing" reaction that further separates the fat and minerals from the protein. This protein, which is mostly what is left in your moldable substance, is called casein. Like all proteins, casein molecules are made up of long chains of amino acids. These molecules are very long and flexible, until they harden.