How cold can an egg get and still be viable for hatching purposes?
If it is frozen it has gone too far. See what CVM said about the yolk. Other than that, there is no clear answer, like almost everything else involving chickens.
There are so many different things involved with whether an egg will hatch or not that you can't really set black and white absolute parameters. Anything from the nutrition value of the parent's feed, how long you store them, turning, humidity, position you store them, and many other factors. The generally accepted optimum temperature for storage is somewhere around 55 degrees Fahrenheit. I don't store them at that temperature while gathering enough for incubation. Mine stay at room temperature, which is quite a bit higher. When it is really hot, some people store them in the warmest part of their refrigerator, or keep a special refrigerator set fairly high to store them in. We may not always get 100% hatches, but we usually do OK. We just do the best we can with what we have.
The further from optimum you get and the longer they are at those temperatures, the less likely they are to hatch. That does not mean they won't hatch, just that they are less likely to hatch.
The spirit of liberty is the spirit which is not too sure that it is right.....Judge Learned Hand (The more sure your are that your way is the only right way, the more likely you are wrong.)
The spirit of liberty is the spirit which is not too sure that it is right.....Judge Learned Hand (The more sure your are that your way is the only right way, the more likely you are wrong.)
