Understanding 400°F in Cooking
400 degrees Fahrenheit (204.44°C) is a hot oven temperature that's perfect for achieving crispy, golden results. This high heat is ideal for roasting vegetables, baking bread, and cooking foods where you want a caramelised exterior with a tender interior.
UK Gas Mark Equivalent
In the UK Gas Mark system, 400°F (200°C) is equivalent to Gas Mark 6. Here's the hot oven reference range:
- Gas Mark 5 = 375°F = 190°C (Moderately Hot)
- Gas Mark 6 = 400°F = 200°C (Hot)
- Gas Mark 7 = 425°F = 220°C (Hot)
- Gas Mark 8 = 450°F = 230°C (Very Hot)
Perfect Foods for 400°F
This temperature excels for:
- Roast potatoes - Crispy golden exterior, fluffy inside (the British Sunday roast essential)
- Roasted vegetables - Carrots, parsnips, Brussels sprouts caramelise beautifully
- Bread and rolls - Creates a good crust while cooking through
- Pizza - Home ovens at 400°F produce decent pizza (though pizzerias use much higher temperatures)
- Chicken pieces - Skin crisps while meat stays juicy
- Yorkshire puddings - High heat is essential for proper rise
Fan Oven Adjustment
For fan-assisted ovens (standard in most UK kitchens), reduce the temperature by 20°C. So 400°F becomes 180°C fan. This accounts for the more efficient heat circulation in convection ovens. Your food will cook evenly without the need for such high temperatures.
The Science of High-Heat Cooking
At 400°F (200°C), the Maillard reaction occurs rapidly - this is the chemical reaction between amino acids and sugars that creates the delicious brown colour and complex flavours on roasted foods. It's why your roast potatoes taste so much better than boiled ones!
Energy Efficiency Tips
Heating your oven to 400°F uses significant energy. To be more economical:
- Batch cook multiple items at once
- Don't preheat longer than necessary (10-15 minutes is usually sufficient)
- Keep the oven door closed - opening it drops temperature by up to 25°C
- Use residual heat by turning off 5-10 minutes before cooking time ends
Safety at High Temperatures
At 400°F, oven racks, trays, and dishes become extremely hot. Always use proper oven gloves (not tea towels) and ensure adequate ventilation. If something spills in the oven at this temperature, it can smoke significantly - another reason to keep your oven clean.