Making Glue

Kitchen Sink Science.
Experiment of the month: Making Glue from Milk.

You will need:

1. Skimmed Milk
2. White vinegar
3. Baking soda
4. Pan
5. Water
6. Sieve/strainer
7. Lolly sticks

Instructions

First heat one and a half cups of milk in a pan, adding three teaspoons of white vinegar when the milk is warm.
Keep heating gently and stirring the mixture and you should see the curds (solid) and whey (liquid) separate.
Strain the mixture using a sieve. Collect any solid lumps.
Place the solid mixture back in the pan and add a small amount of water and a tablespoon of baking soda.
Heat the mixture again until it starts to bubble.
Stir well and let it cool. You can now use it as glue. You might need to add a little more water or baking soda until you get the right consistency. It should look like a thick paste.
Test the glue by sticking two lolly sticks together so that they overlap by 2cm. Remember to leave the glue to set.
Compare the skimmed milk with semi skimmed and with full fat to find out which one forms the strongest glue. You can test the strength by holding one stick and seeing how many pound coins you can balance on the other end before sticks come apart.

Here comes The Science of Glue From Milk!

The vinegar causes the milk to separate into solid curds and liquid whey. The curds form a natural glue.
You can also try adding more vinegar and not heating the mixture to extract the curds.
Different cultures have used this method to make glue for some very large structures over many centuries!

And here are some pictures from the practical…