An egg spoils by bacteria getting inside and reproducing. If bacteria does not get inside, it will not spoil. It does not matter if it is in the refrigerator or on the counter.
If bacteria gets inside, the warmer an egg is stored the faster the bacteria will reproduce. An egg in the refrigerator will last a lot longer than an egg in a warmer counter.
When a hen hides a nest she lays an egg a day for two weeks, sometimes more, then incubates the eggs for three weeks before they hatch. They do not spoil in this five week time period. Why would they spoil on your counter?
When an egg is laid, the hen puts a coating on it called bloom. This coating helps stop bacteria from getting inside. It’s not a perfect coating but it does work really well. When you wash the egg, you take that coating off. An egg that is washed should be stored in the refrigerator because you have removed the bloom. As long as it is not “dirty” an egg should last months in the refrigerator. A clean unwashed egg will last several weeks or even a few months on the counter.
A fertilized egg will develop a little in the mid 80’s or so. It won’t develop enough to hatch but it can get far enough along after several days for it to be noticeable. I don’t know the exact temperature when it starts so I try to keep them below 80. Better safe than sorry.
This article has some good information on how to store eggs for incubation. Remember that these are guidelines, not absolute laws of nature. The guidelines are there to help improve your odds of getting a good hatch. There is no guarantee of perfect success if you follow them exactly nor is there a guarantee of total failure if you violate them some. Just follow them as well as you reasonably can and you will probably do pretty well. Hopefully this link will work this time. I had trouble a few days ago.
Texas A&M Incubation site
http://posc.tamu.edu/files/2012/08/b60921.pdf
The guidelines say to store the eggs between 55 and 65 degrees. This is the ”ideal”. A lot of us don’t have a place to store them that meets this criteria. I sure don’t. I store them at room temperature in a place where the temperature is pretty stable, a cooler part of the house, where sunlight can’t hit them and where the air vents do not blow directly on them. It’s the best I can reasonably do and I usually get pretty good hatch rates. Some people that live in hot climates store the hatching eggs in the refrigerator. It’s the best they can reasonably do and they often get pretty good hatches. The longer they are stored in poor conditions the more likely the hatch rate will drop, but that does not guarantee absolute failure.
Folks, don’t stress out about it. Just do the best you reasonably can and you’ll probably do OK.
