Fall and winter often sees hens slowing down with their laying and since we have been reducing our flocks here on the farm, we don’t have a lot of new birds coming into lay, so we’ve been buying eggs from other producers. Oh the shame! LOL. But I’m okay with it and happy to support other local farms in the process. In addition, with the spring hatching season right around the corner, I thought I’d address something I see every year and do a little write up on egg storage position. It helps to know a bit about egg anatomy to know the how’s and whys of proper storage so we will start with a borrowed image.
Have you ever wondered why an egg has a pointy and a blunt end? When the egg develops, it travels through the hen’s oviduct and spins as calcium forms around the yolk/albumen and membrane. This movement creates a streamlined pointed end in the front, and a blunt end with an air cell at the back (sort of like a bullet going through the barrel of a gun). Once the egg is fully coated in it’s calcium shell and reaches the end of it’s journey, it is flipped over so that the blunt end comes out first. But why?
In architecture, the dome is considered one of the strongest designs. It supports the weight of the roof evenly so that no single point on the dome supports the whole load and gives way under stress.
What has this got to do with laying and storing an egg? The ends of an egg are just like a dome – it’s shell is the strongest on the ends where the greatest arches are! The pointy end is stronger by design, but the blunt end is wider and better able distribute pressure more evenly all over the shell and it has a cushioning air cell beneath the surface. This makes for a better landing, more surface area for cushioning and less likelihood of the egg being broken as it exits the hen’s body.
Great! So should you store your eggs on the blunt end with it’s greater width and weight distribution? No! And here’s why … remember that air cell I mentioned?
The air cell is located at the blunt end of the egg. Air, of course, is lighter than the other contents of an egg. Therefore, if you store an egg with the blunt-side down, the air sac will be at the bottom, where it will push up against the egg whites and the yolk as it tries to rise to the top. As an egg gets older, the strands of proteins that tether the yolk to the egg whites begin to break down, making it easier for air to push the yolk around. Over time, the air cell ruptures transferring bacteria to the yolk where conditions for growth are optimum and your egg will spoil.
Eggs should always be stored with the pointed end down.
If you keep eggs pointy-end down, however, you limit the effects of gravity, because the air sac is already on top. The white or albumen is alkaline and not as conducive to bacterial growth and it keeps the yolk centered nicely within itself even when the air cell size increases. You reduce the risk of the egg spoiling, the strong pointy end protects the egg from breakage at the bottom, and your egg stays fresh for longer!
Why does it really matter? If you sell table eggs and don’t have to store them for any length of time it may not be as necessary to concern yourself with it; however, no one wants their eggs to be the source of someone getting sick and since you don’t know how or for how long they will be stored on the buyer’s end, it is usually best to ensure they are blunt side up when you sell them so the buyer doesn’t have to worry about it. If you wash your eggs this also takes on a more important role, since washing removes the protective bloom on the outside of the egg that helps to limit bacteria from penetrating the shell, there is a greater chance that bacteria will have entered the air cell. Washed eggs should always be stored in the refrigerator to slow bacterial growth.
If you are selling hatching eggs, this takes on a different issue – saddling and bacteria will considerably reduce viability of that egg to produce a chick that makes it through incubation to hatch. Eggs for hatching should be stored in a cool location, blunt end up, and some say to tilt them slightly from side to side several times daily. Eggs for hatching should be incubated as fresh as possible, with storage time less than 2 weeks for optimal viability.