Poached eggs dissolve while cooking? I typically use a little white vinegar to hold my poached eggs together better while cooking (plus, I like vinegar).

Recently, I ran out of white vinegar and swapped in red wine vinegar instead. The egg white nearly dissolved while cooking, leaving behind only the yolk.

Is this due to the change in vinegar? Or might there be other issues at play (heat, pot, egg quality, etc.)?
The likely contributing factors are (and probably more than one, and perhaps all apply):


Older, weaker red wine vinegar, which didn't sufficiently acidulate the water to denature the egg white proteins quickly, thus removing their ability to dissolve
Older eggs, with weaker, looser whites that spread more easily in the poaching liquid, and thus dissolve more easily due to greater surface area
Lower heat of the poaching liquid which would also slow the cooking of the white, allowing it more time to potentially dissolve before the proteins are denatured from heat, and thus can no longer do so