Broken Emulsions

Because a vinaigrette is a temporary or unstable emulsion, sooner or later the vinegar and oil will separate. As the water droplets circulate in the mixture, they bump into each other and, because of their polar attraction (see sidebar), they combine into larger droplets. These larger droplets, in turn, combine with other large droplets. Gradually, the droplets become large enough to separate completely from the oil and form a separate layer on the bottom of the container. When this happens, we say the emulsion is broken.