Onsen Tamago: The Egg Cooked Inside-Out at 68°C — Epoche B1
Onsen Tamago: The Hot-Spring Egg, Made in a Saucepan In hot-spring towns across Japan, eggs are lowered into the spring in nets and sold warm at the source. At a ryokan breakfast in Gero, in Gifu, the egg arrives in a little cup with cold dashi sauce, and it is backwards: the yolk is nearly firm, the white barely set, slipping around it like thick cream. There is no trick, only temperature. A yolk starts to set at about 65°C; the white does not fully set until about 80°C. Hold a whole egg near 68°C long enough and the inside cooks before the outside — the reverse of a boiled egg, which meets the 100°C water white-first. A spring at the right heat does this by itself; a kitchen needs a thermometer. Serves 4. About 35 minutes, almost all of it waiting. Ingredients 4 eggs, taken out of the fridge 30 minutes ahead — a cold egg drags the water temperature down About 2 litres of water — the bigger the pot, the steadier the temperature Sauce: 100 ml dashi, 1 tablespoon soy sauce, 1 tablespoon mirin, warmed together and cooled Method Heat the water to 68°C and turn the heat off. Lower the eggs in gently and put the lid on. Wait 25 minutes. Check twice; if the water falls below 65°C, warm it briefly. Lift the eggs into cold water for two minutes to stop the cooking. Crack each egg into a small cup and pour the sauce around it. The window is narrow: under 60°C nothing sets, and at 75°C a soft-boiled egg appears instead. Get it right and the spoon finds the yolk waiting, dressed in its loose white. References Japan National Tourism Organization (JNTO). (n.d.). Local Cuisine. Retrieved from https://www.japan.travel/en/things-to-do/eat/local-cuisine/ Shizuo, T. (1980). Japanese Cooking: A Simple Art. Kodansha International.