When it goes wrong · Emulsify
Grainy rather than split — visible curds.
Can you save it?
Reviewed for this symptom
Not recoverable as this sauce — the proteins have set, and re-whisking makes scrambled egg in oil. Strain out the curds and use the liquid as a dressing base, or start again with a fresh yolk over gentler heat.
How to confirm the diagnosis
Observable cues, not inferred user state
- Visible curds or a grainy texture rather than separated oil
- The sauce got very hot
- The whisk stopped while it was over heat
Not this?
- The sauce separates into an oily layer and a watery one.
- It formed, then broke a few minutes later.
- It never thickened at all and stayed thin and clear.
What actually happened
Only this symptom
The proteins doing the emulsifying have coagulated. That is a different failure from splitting and a worse one.
The full mechanism
Shared by every emulsify failure
Fat and water do not dissolve in each other, so left alone they separate into two layers — the arrangement with the least contact between them. An emulsion suspends one inside the other as droplets, and it needs two things at once: mechanical energy to tear the droplets small, and an emulsifier to coat each droplet so it cannot merge back. Emulsifiers are molecules with a water-loving end and a fat-loving end — lecithin from egg yolk, casein from butter and cream, the mucilage in mustard, dissolved starch from pasta water. Whisking without an emulsifier gives you a mixture that separates within a minute. Adding fat faster than the whisk can break it leaves droplets uncoated, they coalesce, and the sauce splits.
The full Emulsify lesson — how to tell, where to practise it, what it carries to.
Next time
Prevent this specific failure
Keep yolk-based sauces below about 70°C — off the heat when in doubt — and whisk constantly.
What right looks like
Shared by every emulsify failure
- The mixture turns opaque. Two separate layers are translucent; an emulsion scatters light and goes pale and matte.
- It thickens noticeably even though nothing was added that thickens — the resistance comes from packed droplets.
- It coats the whisk or the back of a spoon and holds a line drawn through it.
- The sound changes as it forms, from a thin slosh to a heavier, quieter sound.