Observations and results
Was the egg that was brought to a boil along with the water overcooked, being more similar to a hard-boiled egg than a soft-boiled one? Were the other eggs much closer to being soft-boiled?
When the egg and water were brought up to a boil together, the egg was probably fairly hard-boiled, with a completely firm, thick white and a hard yolk (although it may have had a slightly less cooked, more orange area in the very center). The egg that was steeped in the just-boiled water should have been much more watery, with a much less firm white that was mostly white (but maybe clear in places) and a slimy yolk. Depending on the exact conditions used, however, this egg may have been slightly more cooked and appeared soft-boiled. The recipe that probably resulted in the most soft-boiled-like egg was just cooking the egg in the already boiling water, which cooked the egg more than did steeping it in the just-boiled water, but less than bringing the egg and water up to a boil together. Another common approach to soft-boiling eggs is using simmering, instead of boiling water. What other commonly made foods can you use science to help perfect the recipe?
Always wash your hands with soap and warm water after handling uncooked eggs because they can carry salmonella. Be sure to also wash objects, such as plates, that came into contact with the uncooked eggs. For this same reason, it is not recommended that you eat any uncooked or partially cooked eggs you prepared in this activity.
More to explore
Anatomy of an Egg , from the Exploratorium
Science of Eggs , from the Exploratorium
How to Get Perfect Soft-Boiled Eggs Every Time , from Brigid Ashwood at Wired
Egg-cellently Cooked Eggs: The Process of Soft-Boiling an Egg , from Science Buddies