What does it mean if one of my hard-boiled eggs floats in the water after cooking? @Food52Hotline
There are some answers online, and this looked like the right one -- http://answers.yahoo.com/question/index?qid=20090912190039AA6I4hO
Another possibility -- if a hard-boiled egg is in very salty water, it may float, but then I would think they all would, not just one -- and it would have to be very salty.
I'd definitely say it's an older egg with a bigger air pocket inside. Might not be rotten, but why take the chance?
Older eggs will float but that doesn't mean they're bad. If I know I have to make deviled eggs for a party I'll set aside the amount I need 3 or 4 weeks ahead of time b/c they're easier to peel. Also I like to tap the eggs on a table to slightly crack them (this lets water in the eggs making them easy to peel.) Set all the eggs in a pot of salted cold water and bring to a boil. As soon as it boils turn off the heat and cover w/a lid. Let them set 15 minutes then drain and run cold water over them till they're cool enough to peel. Perfect eggs every time. Do the same for egg salad.
Old eggs float in fresh cold water because of a large air cell that forms as the egg cools after being laid. As the egg ages, air enters the egg and the air cell becomes larger and this acts as a buoyancy aid. Generally, fresh eggs will lie on the bottom of the bowl of water.
Boil eggs 12 minutes. Remove from water with tongues, place in glass bowl. Refrigerate 2 hours!
Sounds like a party game. Tougher than bobbing for apples.