S.E.T. Rubber Milk

Welcome to another SET (Science Experiment Thursday).  Today we made some rubber milk:

It only requires two ingredients: 

- 1 and 1/2 cups skim milk (skim works the best)

- 4 tsp. white vinegar

Stir the two together for about 10 seconds then place the bowl in the microwave for 2 minutes:

You will notice that the milk has separated into two parts: a liquid and a solid.  Strain the liquid in a strainer.  Allow it to cool.  After it has cooler, touch the solid:

You can even squish it into a ball.  It feels almost like rubber:

Allow it to sit out and harden a bit.  You could even make snowmen or sculptures out of it!  This solid part of the milk is called the curds and the liquid part that was strained out the whey.

Apparently, after a day or two it will feel like plastic.  So we will be leaving ours out to note the changes.

So how does it work?  From Science Fun for Everyone's website:  "Vinegar has a type of acid in it called acetic acid. The acid in the vinegar causes a protein (casein) in the milk to clump together when it is heated. Casein is very similar to plastic because of the tiny molecules it is made out of."

 How fun is science?!  ;)