Long-term Fertilized Egg Storage for Chickens and Quail
Start With Clean, Unbroken Eggs
Starting with clean eggs does not include washing. Egg shells have a cuticle on the outside, which protects the inside from bacteria. Running the eggs under water will wash away the cuticle and make the egg more susceptible to rotting.
For chickens, the eggs should be fairly clean as soon as they have been laid. If the nesting boxes have an adequate amount of filler (straw, grass, shavings) that is cleaned as needed, there shouldn't be poop or mud on the eggs. Any dried dirt or poop on the shell can usually be wiped off with a dry paper towel before storing. A dampened cloth may also work, along with a very fine grit sand paper.
Our coturnix quail eggs regularly have poop attached, but it wipes off pretty easily when dried.
Each egg needs to be inspected for cracking or breaking. If a crack or chip in the shell is present, the egg should be rinsed and used for cooking - even if you scramble the egg, crush the shell and use it as feed to grown chickens. A cracked shell leads to rotting, which could lead to a mini blowout of disgusting proportions. If a rotten egg explodes, it essentially infects the surrounding eggs and stinks. The last time we had an egg "blow up" the smell reminded me of the stink of a skunk mixed with the stench of burning tires. We'd found it in the yard and were thinking of adding it to a broody hen's bucket. The egg was placed in the laundry room and forgotten. Oops.
Store in Cartons or Containers
Egg cartons are great for storing fertilized eggs. We have also stored in wide, shallow containers. They do not have to be shallow, but a deeper container will not hold more eggs since we do not layer them.
When placing the eggs in the container, put the small end down. I always think of the larger end being the bottom, so "Bottoms up!" comes to mind when placing eggs in cartons.
Quail eggs stored in chicken egg containers must be handled with care. While they do not bump into each other when the carton is laying flat, a slight misstep and the small eggs will seemingly 'jump' to a different section. We have learned to insert a cardboard cutout inside the egg carton to keep the quail eggs in place.
We store the containers in a room without a lot of temperature variations. Essentially, away from drafts and direct sunlight. An ideal situation is a temperature of 50 to 60 degrees Fahrenheit with humidity at around 75 percent.
If you will be storing eggs for longer than a week, place the carton in a plastic bag to help reduce the amount of evaporation and err on the side of cooler (50 degrees Fahrenheit) as opposed to warmer. Do not seal the plastic bag.
Turn Your Fertilized Eggs
Stored eggs need to be turned, ideally at least once a day. Eggs should be stored 'bottoms up', so tilting the containers is preferred over just "flipping" the container over. Tilting also decreases the chance of jarring movements or eggs moving out of place, such as quail eggs.
Quail eggs won't want to sit 'bottoms up' in a carton without a bit of support. Placing dried grass in each compartment is an efficient way to keep them placed how you would like.
To tilt the containers, place a block of some sort under one end of the container, such as a brick, phone book, small box or even a pair of folded thick socks. When it is time to 'turn' the eggs again, just switch sides for the block/prop. Twice a day is recommended, making it easy to set the schedule of once in the morning and once at night.
Storage Times Vary
Regular turning, a mild environment, and clean eggs can sit and be turned twice a day for weeks. We have had successful hatches from eggs that sat for two months. Your mileage will vary, but the strict regimen of only using eggs under ten days old is a suggestion and not a rule.
Our eggs are stored in a room of the house that does not have drafts, but is regularly visited. We don't forget to turn the eggs because it is built into the schedule. We have also found that storing eggs in egg racks makes storage and turning much easier. When the rack is full, we put it in the already-set incubator and wait the 16-23 days (depending on the type of egg) for babies to start hatching.