On Food and Cooking

Egg yolk 65

Mayonnaise 400

Water-in-Fat    Emulsions

Butter 550

Vinaigrette 300

Two Liquids: Continuous and Divided The
two liquids in an emulsion can be thought of
as the container and the contained: one liquid
is broken up into separate droplets, and these
droplets are contained in and surrounded by
the intact mass of the other liquid. In the usual
shorthand, an “oil-in-water” emulsion is one
in which oil is dispersed in a continuous water
phase; “water-in-oil” names the reverse
situation. The dispersed liquid takes the form
of tiny droplets, between a ten-thousandth and
a tenth of a millimeter across. The droplets
are large enough to deflect light rays from
their normal path through the surrounding