To emulsify means to combine two liquids that normally do not combine easily, such as oil and vinegar. This is done by slowly adding one ingredient to another while whisking rapidly. This will disperse and suspend one liquid throughout the other.
The two liquids will soon separate unless a third ingredient is added--this is called a liaison or emulsifier, which stabilizes the mixture.
Emulsifiers are contained in egg white, gelatin, skim milk and mustard.To create an emulsion here, we've added a bit of mustard to the vinegar and then drizzled in some oil.
