How to Make Glue from Milk: The Kitchen Chemist

The Chemistry Laboratory and the Kitchen have lots in common. Both contain substances kept on shelves that are combined and reacted in various vessels, whether the baking dish or the beaker, producing desired products. In fact, a lot of chemistry actually takes place when ingredients are combined and heated. The same could be said of a loaf of bread, or a jar of jelly. Though you can purchase glue at any grocery or hardware store, did you know you can make glue right in your kitchen? Does it surprise you that I tell you this article will demonstrate how you can make glue using milk from your refrigerator? Press on with me, and together we will see how.

Making Casein Glue - a Protein Glue

You may know that protein is an important part of your daily diet. For one thing, protein helps build muscles. The primary source of protein in milk is casein. Casein is really not a water-loving substance, so it may surprise you that there is a lot of it in milk.

Because it is a phosphoprotein, that is, because it is not simply an ordinary protein but it contains phosphorous, casein molecules are mildly acidic, and as a result, they repel each other. Because of this, the protein, although not truly dissolved in the clear liquid (mostly water) we call whey, remains suspended in that liquid. For this reason, the molecules don't all come together, or coalesce, to separate out from the milk.

In making your glue, you will deliberately change the chemistry by making the milk itself even more acid than the casein. Doing this causes the casein molecules to come out of the milk.

Let's Do It!

Any milk will do, but to simplify things, purchase a quart of skim-milk at the grocery store. Skim milk is also identified as 0% Fat Milk, or Non-Fat Milk. Pour the quart of milk into a large bowl. Add to it, with stirring, a cup of distilled vinegar (white vinegar). Heat the combination in a saucepan until a white solid separates out.

Now you want to keep the solid, but dispose of the liquid. To do this, take an ordinary coffee filter, and slowly pour the liquid (after it has been cooled) through the filter. Take the solid you collect in the coffee filter into a smaller container.

In a separate container, dissolve some baking soda in water. Use the least water you can to do this. Add this very slowly, with stirring, until you have a liquid that resembles white glue. There! You are done. You have made your own casein glue. You can use it to glue paper, wood, or other porous materials.