We always test our eggs by floating them. They sink, they're good. The last few days we've found this isn't always true. The eggs are older, have not been washed. We tested them in water and they sank, but when we cracked them to cook, the entire inside was black and smelled terrible. There was also one that sank, but when cracked open smelled like rotten milk. Weird. We've always been told that when an egg sinks to the bottom, that means they are good to eat. Anybody have any ideas on what could have caused this? Not all the eggs were bad, just a few.