Additional note to this page ... I think I have shown that eggs may or may not change tone (to a clicky, china sound) if they are taped, as in a circuit of electrical tape around the middle to prevent excessive moisture loss.
I've had the smallest half of my 6 eggs losing weight too fast and I taped them to help balance the whole clutch out better. Two out of the three sounded different afterwards.
So either my two eggs are rotten and both showed after taping, or you should be aware that taped eggs may start sounding 'bad' immediately afterwards, and it probably doesn't mean anything if they do.
This around day 20-27.
I've had the smallest half of my 6 eggs losing weight too fast and I taped them to help balance the whole clutch out better. Two out of the three sounded different afterwards.
So either my two eggs are rotten and both showed after taping, or you should be aware that taped eggs may start sounding 'bad' immediately afterwards, and it probably doesn't mean anything if they do.
This around day 20-27.