Having wondered for some years whether it was in fact an old wives tale, the other day I proved to my own satisfaction that it wasn't!
I'm talking about eggs. I was told years ago, I cannot remember by whom, that if you put eggs in water, they should sink and, that if they float, they are either bad or extremely stale. The other day I grabbed a carton of six eggs with five eggs left in it and put the five eggs in a saucepan of water to hard boil them. All five of the eggs floated and I was slightly surprised at this as I was sure that the carton of eggs with one missing was fresh as I'd only bought it the day before; For that reason, I dismissed it as a problem. Then one of the eggs actually burst and the smell that came out was not pleasant, so I fished the carton they came in out of the wastepaper bin and checked the use-by date on it. Sure enough, the use by date had been and gone several months previously, somehow the carton of eggs had got hidden under other things and overlooked when I threw out all the eggs that were past their use-by date. As you might guess, I took them out of the saucepan and threw them straight on the compost heap where no doubt the local Pine Martens will deal with a few lightly boiled stale eggs without further ado.
I thought the business of eggs floating or not was an old wives tale but it seems that that is not the case at all!
@Paulos_the_fog We never cook an egg without first dropping it in a jug of water, if it sinks it's good, if it floats it contains gas and it's bad, never fails 👍