Boiled egg yolk timing
A yolk thickens around 65°C (150°F) and turns firm past 70°C (158°F), so a minute or two changes it a lot. In simmering water, 6 minutes gives a jammy center, 8 a creamy set yolk, 10 to 12 a firm, pale one.
Stop the cooking with cold water
Eggs keep cooking from their own heat after they leave the pot. An ice bath stops that, so the yolk stays as you timed it, and it helps prevent the green ring. Hard-boiled eggs keep about 7 days in the fridge. Eat soft or jammy ones within a couple of days.
Test yourself
Questions from the interactive lesson, with the answer and the why.
You want a jammy yolk for ramen. About how long do the eggs go in simmering water?
About 6 minutes. The yolk thickens while the center stays soft.
True or false: Overcooked boiled eggs can get a green-gray ring around the yolk, which is harmless.
True. Iron in the yolk reacts with sulfur from the white when the egg is overcooked, and the ring is safe to eat.
What went wrong? You boil eggs for 6 minutes for a soft yolk, then leave them in the hot pot. The yolks come out hard.
The eggs kept cooking in the hot water after the timer. Moving them to an ice bath right away stops the cooking.
Fill the blank: The harmless green-gray ring on an overcooked yolk comes from ___ reacting with sulfur.
The harmless green-gray ring on an overcooked yolk comes from iron reacting with sulfur. Iron from the yolk and sulfur from the white form iron sulfide.
Judging by its yolk, which egg has been cooked the longest?
A firm, pale yellow yolk with no wet center. It reached the highest internal temperature.
