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TechniqueFebruary 7, 2026· 5 min read
The Science of Perfect Boiled Eggs
Soft, medium, or hard — learn the exact time and temperature for your preferred doneness.
Why Are Boiled Eggs So Inconsistent?
How Eggs Cook
- Whites: Start setting at 62°C, fully set at 80°C
- Yolks: Start setting at 65°C, soft at 70°C, hard above 77°C
Perfect Timing Guide (from boiling water, fridge-cold eggs)
| Doneness | Time | Yolk |
|---|---|---|
| Soft | 6:30 | Runny |
| Medium-soft | 7:30 | Jammy |
| Medium | 9:00 | Slightly moist center |
| Hard | 12:00 | Fully set |
Key Points
- Use fridge-cold eggs for consistent results
- Start from boiling water — not cold
- Ice bath immediately to stop cooking and ease peeling
Why Yolks Turn Green
Overcooked yolks get a green ring — iron from yolk meets sulfur from white. Harmless but avoidable by keeping it under 12 minutes.
Pro tip: Week-old eggs peel much easier than fresh ones!