Cooking regime

Dry heat via fat

Fat is a dry medium — it contains no water — but it conducts heat far better than air and it wets the surface of food completely. That combination gives fast, even, high-temperature cooking with all the browning of an oven and none of the waiting.

Why fat is such a good medium

Air is a poor conductor. Even at 200°C it takes a long time to transfer heat into food, which is why an oven takes an hour to do what a pan does in ten minutes.

Fat conducts far better and, crucially, wets the surface completely. Where air touches food only at the points of contact and leaves a still, insulating layer against it, oil flows into every crevice and stays in contact everywhere. That means heat arrives evenly across the whole surface at once.

And because fat contains no water, it can be held well above 100°C indefinitely — so the food surface can dry and brown without any of the stalling that a wet environment causes.

Fat also dissolves and carries flavour compounds that water does not, which is why fried food tastes different from oven-cooked food even at the same degree of browning.

The methods in this regime

Sautéing

A little fat, high heat, small pieces, constant movement.

Pan-frying

More fat, medium-high heat, minimal movement, a crust the goal.

Shallow frying

Fat partway up the food, turned once. Between pan-frying and deep frying.

Deep frying

Full immersion, so heat arrives from every direction at once. The most even version of the regime.

Confit

Low-temperature immersion in fat over hours. The gentle end of the same environment.

Roasting in fat

Roast potatoes and duck fat. A hybrid: oven air plus a fat layer at the contact surface.

What decides the result

• Temperature. The single variable. Too cool and food absorbs oil; too hot and the surface burns before the interior cooks.
• Not crowding. Cold food drops the fat temperature, and a lot of cold food drops it into the greasy zone.
• A dry surface. Water in hot fat spatters violently and cools it.
• The right fat. Neutral and high smoke point for anything hot and prolonged; butter and olive oil for flavour at lower temperatures.
• Depth. More fat holds its temperature better when food goes in, which is why deep frying is more forgiving than shallow.
• Draining. On a rack, so steam escapes rather than softening the base.

Why the temperature range is so narrow

Most of this regime lives between roughly 160 and 195°C, and both ends of that range have a real consequence.

Below about 160°C the food does not generate steam fast enough. Steam pushing outwards is what keeps oil from soaking inwards, so weak steam means oil seeps in and the result is heavy and greasy rather than crisp.

Above about 195°C the surface browns and then burns before heat has conducted into the middle, and the oil itself begins breaking down, which tastes acrid and shortens its usable life.

That is a narrower window than any other cooking regime works within, and it is why frying is the one domestic technique where a thermometer genuinely earns its place. It is also why crowding matters so much: enough cold food dropped in at once takes the oil straight out of the bottom of the range.

Common questions