When it goes wrong · Simmer
A cream or egg sauce split.
Can you save it?
Reviewed for this symptom
Off the heat, whisk a spoonful of the split sauce into a fresh yolk or a splash of cold cream, then whisk the rest in gradually; a hot cream sauce often rejoins with cold liquid alone. If it is grainy rather than oily, the egg has scrambled and it will not come back — strain and use it as a thin sauce.
How to confirm the diagnosis
Observable cues, not inferred user state
- Oil or curds separating from the liquid
- Bubbles were breaking the surface
- The pan was thin or the heat high
Not this?
- Stock is cloudy and greasy.
- Fish or dumplings fell apart.
- A cornstarch-thickened sauce stayed thin and tasted chalky.
- Rice came out gummy and mushy.
- Rice is still crunchy in the middle.
- The rice burnt and stuck to the bottom of the pot.
What actually happened
Only this symptom
Reached a boil. Emulsions and coagulating proteins both fail at the top of the range.
The full mechanism
Shared by every simmer failure
Water boils at 100°C and cannot get hotter at normal pressure, so a rolling boil is not hotter than a simmer by more than a few degrees — around 85-96°C against 100°C. The difference is not temperature but agitation. A boil is thousands of collapsing bubbles delivering mechanical energy, which shreds fish, clouds a stock by emulsifying fat and driving protein scum back into suspension, and breaks the emulsions in cream sauces. A simmer delivers the same heat without the turbulence. This is why almost everything long-cooked wants a simmer: the extra few degrees buy almost nothing and the agitation costs a great deal. The exceptions are when you specifically want that energy — reducing fast, or gelatinising starch in a slurry, which genuinely needs to reach a boil to thicken fully.
The full Simmer lesson — how to tell, where to practise it, what it carries to.
Next time
Prevent this specific failure
Keep cream and egg sauces below a simmer, off the heat when adding yolks, and use a heavy pan.
What right looks like
Shared by every simmer failure
- Bubbles rise lazily from one or two points on the base and break gently at the surface — not a rolling motion across the whole pan.
- The surface trembles more than it moves.
- A stock stays clear. Cloudiness is the reliable sign it has been boiling, not simmering.
- Adjusting to a true low simmer usually means a lower flame than feels right, and often a lid set slightly ajar.