Cooking regime

Low temperature, precisely controlled

In every other cooking regime the medium is hotter than the target and the skill is knowing when to stop. Here the medium is held at the target, so the food approaches it and stays there — and timing stops being the thing that can ruin it.

The gradient collapses

Cooking normally produces a temperature gradient: the surface is much hotter than the centre, and the whole art is judging the moment the centre arrives before the outer layers have gone too far. That is why a conventionally cooked steak has a grey band under the crust.

Hold the medium at the target temperature and the gradient largely disappears. The whole piece approaches one temperature and then stops, because there is no hotter region for heat to come from. The result is even from edge to edge, and — more usefully — it cannot overshoot.

The trade is that nothing in this regime can brown. Browning needs a dry surface above 140°C, and by definition the medium here is at the temperature the food should reach, which for meat and fish is far below that. Every technique in this regime ends somewhere else.

What lives here

Sous vide

Sealed food in precisely controlled water. The clearest example of the regime.

Very low roasting

A 100 to 130°C oven for a large joint, finished with a hot sear. The domestic approximation.

Slow-cooked confit

Fat held at a low temperature for hours.

Poaching with the heat off

Bring the liquid up, add the food, cover, turn off. The temperature can only fall, so overcooking is very hard.

Long low braising

A 130 to 140°C oven for six hours, which converts collagen without the fibres contracting hard.

What does not live here

Anything that needs a crust or a surface. This regime always needs a finishing step.

What it buys, and what it costs

• Buys: evenness. Edge-to-edge doneness that no other regime achieves.
• Buys: safety margin. The food cannot overshoot, so the timing question becomes "has it arrived" rather than "have I missed it".
• Buys: cooking ahead. Food can be brought to temperature, chilled and finished later.
• Buys: tough cuts kept pink. Long holds convert collagen at temperatures that would never be reached in a braise.
• Costs: time. Hours where conventional cooking takes minutes.
• Costs: no browning, no fond, no pan sauce. All of that has to be added at the end.
• Costs: equipment, and for meat and poultry, attention to food safety guidance that is genuinely different from conventional cooking.

Why time behaves differently here

In every other regime, time is the dangerous variable — a minute too long and a steak is ruined. Here it is much closer to being a free parameter, and that changes how you plan a meal.

Once the food has reached the medium temperature it stops changing in the way that matters, so a steak can sit in the bath for an extra half hour while something else is finished. That is why restaurants adopted the regime long before home cooks did: it decouples when food is ready from when it is served.

It is not infinitely free. Over very long holds the texture does change — lean fish turns mushy after a couple of hours, and meat held for a day or two becomes noticeably softer as connective tissue converts. So time is not a risk of overcooking; it is a slower dial that controls texture instead.

Common questions