Vegetables
Kale
The one vegetable with a published temperature FIFTY degrees below everything else in its chart.
What it does in fast-moving hot air
A kale leaf is a few cells thick with an enormous surface area for its mass and almost no thermal buffer. At 200°C the edges reach the temperature at which the leaf's sugars and proteins scorch long before the middle of the leaf has dried, so the result is bitter black frills around a limp centre. At 150°C the water leaves slowly enough that the whole leaf dries at roughly the same rate and becomes brittle rather than burnt. It is dehydration with a bit of browning, not roasting, and the ten-to-twelve-minute time is what drying takes. It is also light enough to be picked up and blown around by the fan.
Why the cut matters
Kale crisps are the clearest single demonstration in the catalogue that temperature is a property of the food rather than of the appliance. Every other vegetable in the chart this figure comes from is cooked at 200°C. Kale is 150°C, and the reason is entirely about what a leaf is.
Cooking pages
- Kale crisps — Ten to twelve minutes at 150°C — fifty degrees below everything else in the chart.
There is deliberately no cooking time on this page. A food does not have one — a cut, at a thickness, in a state, at a loading, in a particular appliance does. That is what the pages above are for.