How can I tell if an egg froze?

[Andi]

We have temps in the upper teens right now and when I went out to change the girls water to some that's not frozen I looked for eggs and did find one. It was pretty cold. My girls just started laying a couple weeks ago and never sit on them at all. I'm not sure they do that anyway, seeing I'm new to this chicken thing. For now they haven't started laying them in the boxes yet either. (Yes, I have a golf balls in there for dummies.) I'm using the deep litter method and on the floor is where they are getting laid, but its an unheated coop.

I did a search for seeing if there was a thread on how to know if an egg has froze or not, but all I found was threads on whether or not they are still okay to use. (Which I learned they are but are better used for cooking because they are rubbery once they have frozen.)

Money is tight this Christmas and I was planning on sending my brother, who lives half way across the country, eggs for his present. I sure would hate to send him some duds when I'm showing off. He's never eaten fresh eggs before and I'd like it to be a pleasant experience.

At this point I don't see any cracks or fractures in the shell. Does that mean I'm safe to assume it won't be a rubbery egg?

While I'm on the subject, how long can eggs be out in temps like these and not freeze?

 

[Katy]

Unless they have frozen enough to crack I don't know of a way to tell.

 

[Andi]

Do you think it will be rubbery?

 

[Wildsky]

Yeah if the shells crack for sure. I think if you crack an egg to check right away - the whites will be kinda milky (?) looking and thicker than normal.
I'm not sure if once they're warmed back to a decent temp if there would be any way to tell.