Inspired by Auntie Fashion's Expand Your Fashion Vocabularly, I've decided to introduce a regular (weekly? daily? only time will tell) cooking glossary. This week (or day, or month, or whatever): Emulsion
A mixture of one liquid with another with which it cannot normally combine smoothly — ie. oil and water. Emulsification is achieved by slowly (one drop at a time) adding one ingredient to the other while mixing rapidly. This disperses and suspends minute droplets of one liquid throughout the other, producing a thick and satiny result. Examples: mayonnaise, hollandaise sauce.
Image courtesy of ehow.com