“Homemade food colorings” experiment
How to make healthy food dyes at home
The word “dyes” often calls up associations with something artificial and harmful, but this doesn’t have to be the case. In this experiment, you will learn how to use vegetables to make safe, natural dyes.
This is a safe experiment. Observe safety rules when working with boiling water and heating devices.
Reagents and equipment:
- 200g spinach;
- 2-3 beets;
- 100g onion skin;
- glass jar;
- frying pan;
- 1 tablespoon of 9% vinegar;
- bandage or gauze;
- cutting board;
- 100mL 40% ethanol solution.
Beetroot dye: grate 2-3 beetroots, put the pulp in the frying pan, add 200mL water and a tablespoon of 9% vinegar, and stew for 15 minutes. Filter the stew through the funnel with gauze. Spinach dye: put 200g finely-chopped spinach in a frying pan and add 100mL 40% ethanol. Stew for 15 minutes. Filter through the funnel with gauze.
Onion skin dye: pour 500mL boiling water over 100g onion skin and leave for 15-20 minutes. Filter through the funnel with gauze. The dyes are ready!
Put boiled eggs in the dye solutions for 30-60 minutes. Notice that the eggs change colors. Spinach leaves contain a green pigment called chlorophyll, which dissolves well in ethanol. Onion skin contains a pigment called beta-carotene, which gives the skin its golden color and dissolves well in hot water. Beetroot contains a mixture of different pigments that color it red. They dissolve well in water but decompose when heated for long periods of time. Some vinegar must be added to preserve their color. Eggshells mainly consist of calcium carbonate, which has a porous structure that can easily absorb dyes.