Last year, I purchased a bulk amount of the clear, hexagonal six-pack egg cartons when they were on sale. I decided to sell about ¾ of them so that my egg cartons would be free to me, so I brought them with me when I’d go to poultry sales. To show folks how nice they could be for gifts, I would bring a sample with colored eggs from my mixed flock all wrapped up with a little bow and tag.
Rather than switch out my sample eggs, I just kept the sample six pack in the fridge and brought it with the same eggs each time. Well, with sales over for the year, I decided to finally do something with those eggs.
These eggs have been in my fridge since March, so they are a full eight months old. I thought I’d crack them open and see how they kept.
All of the eggs still showed spring’s bright golden yolks. The whites and yolks were very thick, and the inner membrane easily pulled away from the shell and towards the gluey insides.
However, these eggs smelled perfectly normal. Basically, they were perfectly edible eggs that had thickened because water had evaporated through the shell for many months. I cooked them up and fed them back to my flock which also had no complaints about the old eggs.
Mother Earth News conducted an experiment in 1977 comparing methods of egg storage and different types of eggs: fertile and unfertile, washed and unwashed, homestead or commercial, etc. Two of their conclusions apply to my eggs and their storage conditions:
 Unwashed, fertile homestead eggs seem to store much better than washed, unfertile agribiz eggs. Why? Probably for the simple reason that they’re unwashed … and not because they’re fertile. Hen fruit, as it comes from the chicken, is coated with a light layer of a natural sealing agent called “bloom”. And, while a good wash may make a batch of eggs look more attractive, it also removes this natural protective coating … leaving the eggs more subject to aging and attack by the air and bacteria in the air.
 The very best way we’ve found to stash eggs away for long-term storage is in a sealed container at a temperature of 35° to 40°F. Their whites may become somewhat runny looking over a period of time, but even after seven months—the cackleberries stored in this manner smell good, taste good, have a good texture, and—in short—seem “almost fresh”.
Mine were fertile, unwashed eggs from very well-fed hens which were kept in a closed, plastic container in the refrigerator. It seems that, as long as I have a fridge at my disposal, this is the best way to store extra eggs long-term. If refrigeration isn’t possible, it seems that keeping eggs in sodium silicate, waterglass, or “submerged in a solution of 16 parts water/2 parts lime/1 part salt, packed in lard, and coated with lard” are a close second at about five months of storage, as long as you check each egg by cracking it into a cup before usage.
In all cases, unwashed eggs fared the best, so don’t wash or even rinse until you are ready to use an egg. Brush debris off of lightly soiled eggs and feed heavily soiled eggs back to the flock hardboiled. Store them pointy-end down just as if you were collecting eggs for hatching.
Interestingly, Mother Earth News’ egg whites became runny after long-term storage while mine became gluey. I wonder why mine became drier and theirs seemingly wetter. My six-pack container allowed some air flow; maybe a completely sealed container would allow less evaporation? Possibly the difference is related to the hens’ diet before laying the eggs. Has anyone else stored eggs long term? How did you store them, and in what ways did the egg whites and yolks change over time?