Folks often ask us how long eggs can last, or how they should care for eggs. The simple answer is that refrigerated eggs will stay food safe for a long time. The long answer turns out to be a bit of a rabbit hole.
It makes sense that egg longevity varies with handling. Temperature is the most important variable, but another is washing. Did you know that eggs are naturally covered in a water-soluble protective coating? This is called the cuticle, or bloom, depending on who you ask. The egg shell seems hard and solid, but it’s actually more like a mesh at the microscopic level. This mesh allows moisture and gasses to pass through the shell, along with things like microbes and contaminants that may be around. The natural bloom coating helps seal that mesh and limit contaminant passage through the shell.
When industrial eggs are collected, they are washed. That washing process removes the natural protective layer. Some industrial producers apply a replacement layer, and some don’t do anything. Isn’t it just like our high-intervention food supply chain to remove a natural barrier only to add a synthetic barrier back? We don’t think this is natural, so we don’t wash our eggs.
But what if they have dirt, or mud, or poop on them? Well, we don’t sell those to the general public. Often we eat them ourselves, or share them with folks who understand why they are dirty. But doesn’t that impact profits? Yes, which is why industrial producers do wash their eggs. We strive to provide management practices that help minimize egg contamination, such as giving the hens a path to the nest boxes that will help clean off their feet. We keep absorbent materials in the laying boxes.
In our own kitchen, sometimes we wash the eggs right before we use them, so that exterior dirt doesn’t fall into the bowl that we are cracking the eggs into. We almost always crack our eggs into a separate bowl before adding them to a recipe, just to be sure that the eggs are good.
If you’d like more reading about how egg handling impacts longevity, see this article:
http://www.motherearthnews.com/real-food/how-to-store-fresh-eggs-zmaz77ndzgoe.aspx