Cooking uncovered in an oven's dry heat, so the surface browns while the interior comes up to temperature.
Technique at a glance
A compact visual model of the lesson. Use the full mechanism and success criteria below when you practice.
Concept
Cooking uncovered in an oven's dry heat, so the surface browns while the interior comes up to temperature.
What changes
Dry air is a poor conductor of heat compared with water or metal, which is why an oven at 200°C does not cook nearly as fast as boiling water at 100°C.
What good looks like
Pieces sizzle audibly when the tray is opened; silence means the oven has lost temperature or the tray is crowded.
Practice counts when you cook
Reading this brief does not change your School state. Finish a real practice dish in Cook mode and log the cook; that cook is the evidence that advances the skill.
What to focus on
Mechanism
Dry air is a poor conductor of heat compared with water or metal, which is why an oven at 200°C does not cook nearly as fast as boiling water at 100°C. That poor conduction is the point: it lets the surface reach browning temperature — above roughly 150°C — while the interior climbs slowly enough to finish at the same time. Two things spoil it. Moisture is the first: any water on the surface, or steam trapped by crowding or a lid, holds the surface at 100°C and it cannot brown until that water has gone. Contact is the second: a hot tray transfers heat far faster than the air does, so the underside browns hardest, and food touching its neighbours has no exposed surface between them and steams in the gap. This is why roasting is the technique most improved by using a bigger tray.
Success criteria
Pieces sizzle audibly when the tray is opened; silence means the oven has lost temperature or the tray is crowded.
The undersides are darkest, because that is where conduction rather than convection is doing the work.
Fat has rendered and pooled rather than sitting white on the surface.
For meat, the only reliable doneness signal is internal temperature — colour tells you about the surface and nothing about the middle.
Failure guards
Vegetables are soft and pale rather than browned.
Crowded tray. Released moisture cannot escape, so everything steams in it. Two trays, always, rather than one deep pile.
Burnt outside, raw inside.
Oven too hot for the thickness. Large pieces need lower heat and longer, or a hot start followed by a lower finish.
Meat is evenly grey from edge to centre.
Oven too low for too long — the whole piece drifted to the same temperature with no gradient and no crust.