An emulsion is when two liquids do not mix. Oil and water is the most common food emulsion. When water is mixed with oil, oil droplets can be seen in the water. To keep emulsions from separating, an emulsifier or stabilizer must be added. Examples include lecithin or egg yolk or starch, powders, or gums.

A common emulsion is mayonnaise. Mayonnaise consists of egg yolks mixed with an emulsion of oil and vinegar. Egg yolks act as the emulsifier and allow the vinegar and oil to form a stable emulsion. Otherwise there would be droplets of oil and vinegar in mayonnaise and it would not be smooth.

Other emulsions include frozen desserts. Many frozen desserts such as ice cream and bombes contain water and cream. A stabilizer or emulsifier to keep the cream from separating from the water must be added. In the youth experiment in Level C, the emulsifier is gelatin.


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