Making an emulsion
An emulsion is a mixture of two liquids which normally would not mix together (such as oil and water). A third ingredient, called an emulsifier, stabilises the mixture.
- Pour some oil then some water into a container. Note that the two liquids are not miscible (they do not mix together).
- Add an egg yolk and mix all three ingredients together;
We can observe the solution become homogenised.
Why? Because the egg yolk contains an emulsifier called lecithin and this stabilises the emulsion.