What Is Egg Bloom?
Just before laying an egg, the hen adds a protective layer called “bloom” or cuticle to the outside of the egg. This coating seals the shell pores, prevents bacteria from getting inside the shell, and reduces moisture loss from the egg. These are all things designed to make the egg last longer.
Are All Eggs Protected By Bloom?
All chickens add the protective bloom to an egg just before they lay it. However, because of the conditions at some large egg operations in the United States, commercial (grocery store) eggs are required to be washed right after collection. This is done to make them appear clean and presentable.
Of course, this destroys the protective egg bloom. Then, to try replacing the natural bloom, most commercial packers spray shells with a thin film of mineral oil. That’s why grocery store eggs sometimes appear shiny.
The Backyard Chicken Advantage
An advantage of having backyard chickens is that we can assure sanitary conditions; so the natural protective bloom can be preserved. If the nest boxes are kept clean, most eggs come out spotless, so washing after collection is unnecessary (read more on washing eggs or not HERE).
Eggs that have their protective bloom will last for months, but washing them right before cooking is a good idea.
Occasionally, an egg will come out a little dirty, or feathers and nest box shavings will stick to the fresh (still wet) bloom. If shavings or feathers have gotten stuck, we simply brush them off.
Any eggs that are truly dirty we wash and reserve for immediate use. The bloom should NEVER be washed off any eggs that are planned to be used for incubation and hatching; these eggs need all of their natural protection (see Collecting and Storing Eggs for Hatching).
The fact that Mother Nature has provided for natural egg preservation, and our commercial food production methods immediately remove it, makes no sense. I wonder if there are any large producers smart enough not to remove the “bloom”?
For a more in-depth look at the anatomy of an egg, check out this article from Chickens Magazine (The Anatomy of An Egg).
Marie Greenway says
Is it possible to replace the egg bloom again ????
I preserving eggs and they must have the cuticle or protective covering.
Please help me!!!
Lesa says
Hi Marie, It’s not possible to put the same egg bloom that a chicken produces back on the egg after it’s been washed off. The best you can do is put a replacement protective covering like mineral oil on the eggs as mentioned above. To do this, just coat the eggs with a thin layer of mineral oil.
Roxanne says
If the egg has been washed, the natural bloom is lost. Some people will rub mineral oil on these type of eggs for preservation.
Jennifer Bachner says
Is there a way to tell if an egg has been washed? I was given a couple cartons of fresh eggs, but I was unable to find out if they’ve been washed or not. I am wondering if there is a way visually to tell. Thank you!
Lesa says
Hi Jennifer,
There’s really not a great way to tell if they’ve been washed or not – so, just make sure to wash them prior to using them 🙂
Katie says
Dear Lesa
I understand that, contrary to the USA, in the EU, it is illegal to wash eggs intended for sale! So those sensible countries preserve the bloom.
Lesa says
HI Katie, that’s what I understand too! We seem to be a little backwards here 🙂
Katie Costello says
Thanks for your reply. I live in the UK, and I’m afraid that once Brexit takes effect on 31/12/20, , we might stop following the EU rule about washing eggs! Oh no!
Desiree Wren says
Is there a way to clean eggs without destroying the bloom?
Lesa says
Hi Desiree, we brush them off, but I don’t know how to clean them with water without destroying the bloom.
Debi619 says
One egg broke and I rinsed the yolk off of the remaining eggs with gently running water. Did this also remove the bloom?
Lesa says
Hi Debi, it’s hard to say for sure, but it likely removed at least some of the bloom when you rinsed the eggs with water.
Gary Makus says
I was told the only hard boiled egg that peels are old eggs. any way around this?
Lesa says
Hi Gary, I steam eggs to hard boil them and am able to peel even very fresh eggs that way. Here’s the post on how to steam eggs: http://www.betterhensandgardens.com/easy-peel-hardboiled-fresh-eggs/