Tier 4 · Wet Heat

TO SIMMER

Holding a liquid just below the boil, where it cooks steadily without the violence that would tear delicate things apart.

Why it works

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.

How to tell

• 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.

When it goes wrong

Stock is cloudy and greasy.

Boiled. Agitation emulsifies fat into the liquid and breaks up the protein scum that would otherwise be skimmed off.

Fish or dumplings fell apart.

Too vigorous. Delicate proteins need heat without mechanical force; poaching temperature is lower still.

A cream or egg sauce split.

Reached a boil. Emulsions and coagulating proteins both fail at the top of the range.

A cornstarch-thickened sauce stayed thin and tasted chalky.

The opposite error. Starch needs to actually boil to gelatinise fully; a simmer is not enough here.

Rice came out gummy and mushy.

Too much water, or a boil where a simmer should have been. Absorption rice counts on a measured ratio under a closed lid; extra water and hard agitation scrub loose starch off the grains and cook it into paste. Rinsing the raw rice until the water runs clear removes most of that starch before it can turn to glue.

Rice is still crunchy in the middle.

Not enough water or not enough time — the outside of each grain gelatinised and sealed before the centre could hydrate. High heat makes it worse by boiling the water away before it is absorbed. Add a few spoonfuls of water, cover tightly, and give it ten more minutes on the lowest heat.

The rice burnt and stuck to the bottom of the pot.

The heat stayed high after the water was gone. Steam holds the pot at 100°C only while there is water left to boil; the moment it is absorbed, the bottom layer climbs toward scorching. A heavy pot, the lowest heat, and ten minutes of rest off the heat are the protection — and a toasted, not burnt, bottom layer is a prized dish in many rice kitchens.

Recovering it

A cloudy stock cannot be made clear by straining alone, though a slow strain through cloth helps and chilling lets the fat lift off in a solid cap. Broken sauces come back by whisking into fresh emulsifier off the heat. A thin starch sauce is easily fixed — bring it to a proper boil, which is the step that was skipped. Fish that has broken up is a texture loss, not a flavour loss; it becomes a soup or a fishcake.

Where to practise it

It carries to

Recipes using it

Generated from recipe step verbs and ingredient preparation forms. It is never authored, and it cannot drift from the recipes.