processor makes this process nearly foolproof). As the oil
falls into the bowl, the rapid action of the whisk quickly
breaks it up into tiny droplets, which are kept suspended
with the help of the emulsifiers in the egg yolk.
Here’s what happens to that mayonnaise in the bowl as
you add more and more oil to it:
- When the oil and water is at a 1:1 ratio, or one with less
oil, there is no possibility of a stable emulsion forming.
The fat won’t break up and get coated by the water, nor
will the water be able to suspend the fat within it. At this
stage, your mayonnaise looks like a thin, cloudy liquid. - As the oil to water ratio approaches a 3:1, your mixture
begins to resemble a mayonnaise, albeit one that flows
more like a vinaigrette. As more and more oil is
incorporated into the emulsion, the mayonnaise starts to
become opaque, because the tiny drops of oil refract light
differently than a liquid mass of oil. - As the ratio passes a 5:1, the mayonnaise begins to get
much thicker—thick enough that the peaks will hold when
you pull the whisk out of it. It seems counterintuitive:
mayonnaise is thick, oil is thin, so adding oil to
mayonnaise should make it thinner, right? Wrong. We
know that oil droplets in a sea of oil can swim around and
float past each other quite freely and that in an emulsion,
they are trapped in a tight matrix of droplets separated by
water. In order to flow, that water needs to be able to
move freely around the system. As you add more and
more oil to the mayonnaise, the water separating each
droplet of oil gets stretched thinner and thinner, severely