Cooking method

Sous vide

Sous vide means sealing food in a bag and cooking it in water held at an exact temperature. Because the water can never be hotter than the target, the food can never overshoot it — which removes the single largest source of error in cooking meat and fish.

Why it works

Conventional cooking applies heat much hotter than the target and relies on you taking the food off at the right moment. A steak in a 200°C pan has a surface at 150°C and a centre climbing steadily, and the whole skill is judging the instant to stop.

Sous vide inverts that. The water is at exactly the temperature you want the food to reach — say 54°C for a medium-rare steak — so the food approaches it and then stops. It cannot go further, however long it sits. The timing question becomes "has it got there yet" rather than "have I missed it".

The secondary benefit is evenness. Conventional cooking produces a gradient: the outside is well done, the centre is rare, and a band in between is grey. Sous vide brings the whole piece to one temperature, so it is the same colour from edge to edge.

What it is genuinely good at

• Steak and lean meat, cooked edge to edge and then seared hard for thirty seconds a side.
• Chicken breast, which is otherwise the hardest common thing to get right.
• Eggs, held at a temperature between the white's setting point and the yolk's, which produces textures no other method can.
• Tough cuts, over very long periods — twenty-four to forty-eight hours converts collagen at a much lower temperature than braising, giving meat that is both tender and still pink.
• Fish, which has an extremely narrow window conventionally.
• Cooking ahead. Food can be brought to temperature, chilled, and finished later — which is why restaurants adopted it first.

What it cannot do

• Brown anything. Water caps at 100°C and browning needs 140°C and a dry surface. Every sous vide recipe ends in a pan, a grill or a blowtorch.
• Produce a fond or a pan sauce, because the juices are in the bag rather than in a pan.
• Work quickly. A thick steak takes an hour or more to come to temperature; conventional cooking takes ten minutes.
• Improve vegetables much. They need higher temperatures to soften, so the precision buys less.
• Replace judgement in a busy kitchen. It is a method for planning ahead, not for improvising.

The sequence

1. Season the food and seal it — a vacuum sealer, or a zip bag lowered into water so the pressure pushes the air out.
2. Set the circulator to the target temperature and let the water come up before the food goes in.
3. Cook for long enough that the centre reaches temperature. Thickness decides this, not weight.
4. Take it out and dry the surface completely. This is the step people skip and it decides how the sear goes.
5. Sear hard and briefly in a very hot pan, or under a grill. Thirty to sixty seconds a side is enough — the interior is already done.
6. Rest very briefly, or not at all. Sous vide meat needs far less resting because it was never violently heated.

Common questions