Sticky fingers? What causes it?

You've probably experienced this too: You've eaten something with your fingers and they're all sticky afterwards. Or you've helped to bake a cake, and the mixing bowl is very difficult to clean because the batter sticks to it. Why does this happen? And could you make glue out of these things? Try it out.

Before you get started

If you are experimenting at home:
1. Let your parents know and discuss the experiments with them beforehand.
2. Do not eat or drink at your workspace.
3. Wash your hands thoroughly before and after the experiment.
4. Be careful and cautious with the materials.

Graphic figure boy pouring liquid in flask

You will need

A number of substances you can test:
- Sugar
- Baking powder
- Cornstarch
- Table salt
4 glass bowls
4 teaspoons for stirring

Let’s get started!

1. Preparation

Pour about a tablespoon of each substance into a small bowl.

glass bowl with white paste on black background

2. Mix with water

Now slowly and carefully add enough water to each of the four samples to make a thick paste, stirring the mixtures constantly. Are some of the substances more difficult to stir than others? Rub each of the samples between your fingers. How does it feel? Which substances make your fingers sticky, and which do not? Two of the substances mentioned here can be used to make adhesives. Which are they?

Did you know?
Glue and baking ingredients – where is the connection?

Answer:

Anyone who has ever baked a cake knows that raw cake batter is quite sticky. Besides eggs and milk, cake dough also contains flour and sugar. One of the main components of flour is starch.

Our experiment shows that starch mixed with water makes a very sticky paste. The starch paste is not yet a glue, but if you heat it, you get a simple paper glue. And sugar water is also a very sticky liquid.

Therefore, starch and sugar are not only baking ingredients, but are also suitable as natural raw materials for glue.