Rescuing a Separated Sauce

When an emulsified sauce breaks and the droplets of the dispersed phase puddle together, there are two ways to reemulsify it. One is simply to throw the sauce in a blender and use its mechanical power to break the dispersed phase apart again. This generally works for sauces that still have plenty of intact emulsifier and stabilizer molecules in the sauce, but not for cooked egg sauces that have been overheated and their proteins coagulated. The second and more reliable technique is to start with a small amount of the continuous phase, perhaps supplemented with an egg yolk and its wealth of emulsifiers and stabilizers, and carefully beat the broken sauce back into it. If proteins in the initial sauce had coagulated from overheating, the lumps should be strained out before reemulsifying; otherwise the rescue process may leave the protein particles too small to strain out, but large enough to leave a grainy impression in the mouth.