12: Dyeing your eggs

Eggs have been used since ancient times as a symbol of rebirth and renewal and have always been associated with Spring. The ancient Persian myth suggests that the Earth hatched from an egg at the time of the equinox in Spring. The egg also had symbolic meaning for the Egyptians, Romans, Gauls and Greeks. It has long been used by Christians and the eggs were often dyed to symbolise the Lent and Easter ceremonies.

The first dyes were derived from plant and animal sources until synthetic dyes became available in 1856. The food colours used today have very strict government regulations about where they can be used. Have fun creating your own designs.

What you will need

250cm3 beakers
measuring cylinder or pipette to dispense 10cm3		 food colouring such as: Erythrosine, Allurs Red, Sunset Yellow, Brilliant Blue, Fast Green (all are available in any food shop)
eggs - preferably hard boiled
ethanoic acid (table vinegar will do)		marble chips
sodium chloride

eye protection

What you do

  1. Put some water into a beaker and add enough drops of food colouring to make a strongly coloured solution.
  2. Eye Protection
    Add about 10cm3 of ethanoic acid (the chemical name for vinegar).
  3. Dip your egg in the solution until it has taken up the dye.

YOU MAY LIKE TO INVESTIGATE THE FOLLOWING FACTORS:

  1. What is the effect of varying the concentration of vinegar?
  2. What is the effect of varying the concentration of dye?
  3. Does pre-treating the egg in vinegar have an effect on the absorption of dye?
  4. Do marble chips absorb dye like eggshells?
  5. Is there something on the surface of an eggshell that makes an egg different from marble chips?
  6. Does the presence of sodium chloride in the dye solution have an effect on dyeing?
Eye Protection
eye protection must be worn

Biological Hazard
use hard-boiled eggs to reduce risk of Salmonella

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