Is the egg float or sink test accurate?

Completely accurate. An older agg, as part of aging (or going bad) will break down and form a gas. By the time the egg floats the gas is forming, and therefore the egg is on its way out. Within a few more days the breakdown will be active, and you will have bad egg gas. We did a full blown experiment with eggs over a 2 week period in science at school, and you could pick with 100% accuracy bad and good eggs based on the float/sink principle. Interestingly.. goose eggs behave differntly.. but you seem to be talking chicken eggs.

Don't waste good food. The expiration dates are no way near accurate. The best way to tell if eggs and dairy are OK to eat is to look and smell. If they look OK, and smell OK, they are. There are many foods that are good way after their expiration date.

I think this is a safe test. They float because they have started to form gas from going bad. What ever you do make sure you cook them all the way. And if you get any type of bad smell throw them out.

wow. i never heard about this. now i hav to try it myself. thanks

i think i agree the some the responds that said the air bubble increases as the egg get older and hence it floats.Thinking about it rotten egg will produce more air also and the embro will shrink making the egg float. Expired egg few months are tasteless and have rotten smell even when deep fried, it is dry and less watery, i tried before.Yuck.

I think even if the egg is still ok or not, it will still sunk..

I've heard about doing that test too. I think that it works. In all the times I have boiled eggs to make deviled eggs or just hard boiled eggs for a sandwhich they have always sank. Only one time did I have one float so I threw it out. I say give it a try, maybe just with one. If it sinks, cook it up and see how it tastes. Then you'll know if you can use it or not. Or try one that floats and see if it tastes bad lol.