When it goes wrong · Emulsify
It never thickened at all and stayed thin and clear.
Can you save it?
Reviewed for this symptom
Add an emulsifier — a teaspoon of mustard, a yolk, a spoon of the intact sauce — and whisk hard, adding the fat back slowly. Without one, no amount of whisking will hold.
How to confirm the diagnosis
Observable cues, not inferred user state
- Clear layers that never went opaque
- No mustard, yolk or other emulsifier
- It was stirred gently rather than whisked
Not this?
- The sauce separates into an oily layer and a watery one.
- It formed, then broke a few minutes later.
- Grainy rather than split — visible curds.
What actually happened
Only this symptom
No agitation, or no emulsifier. A vinaigrette stirred gently and without mustard is just oil sitting on vinegar.
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
Include an emulsifier and whisk vigorously while adding fat in a thin stream.
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.