How much oil (fat) can one egg yolk hold safely before you risk the sauce breaking?
1 Answer
Surprisingly high -- something like 6 gallons of oil can be emulsified by a single egg yolk. In addition to the site linked, I've seen similar experiments by Kenji Lopez-Alt and James Petersen.
So if your mayonnaise refuses to emulsify, it's NOT because it doesn't have enough egg yolks.