Many folks question what causes chickens to sometimes produce double yolks in their eggs, so here’s an attempt at the explanation.
To Understand What Causes Double Yolk Eggs You Need To Learn About Hens Reproductive System
A hen’s reproductive system (for more in-depth discussion click HERE) consists of an ovary and an oviduct. The ovary contains undeveloped egg yolks. The number of yolks (or ovum) that are contained here are the total number of eggs that the chicken can lay in her life.
These ova are released into the oviduct as each yolk develops. This usually occurs about an hour after the previous egg was laid. However, in young pullets and some heavy breed hens, two yolks are sometimes released within a couple of hours. These become double-yolked eggs.
Heredity can cause some hens or breeds to have a higher propensity for double yolks, but it most often occurs in pullets that are just beginning to lay (learn how we integrate them into the laying flock HERE). It takes a bit for their systems to “get-in-the-groove” of egg-laying. Typically, as hens mature, their systems settle down and they’ll produce one single-yolk egg approximately every 25 hours.
Are These Eggs Safe To Eat?
Yes, double-yolked eggs are safe to eat and are usually longer and larger than a single-yolked egg. The smaller, darker brown egg in the photo above is actually a jumbo-sized (2 ½ oz.) egg, whereas the light brown eggs are 3 1/8 oz. and 3 ¼ oz. respectively; and were both double-yolks.
Each time we’ve raised young pullets, we’ve seen a few double-yolked eggs. But as each group got older, they quit producing the double-yolked eggs.
Double-yolk eggs are not really that rare (about 1 in every 1000) but aren’t often seen in grocery store eggs today because commercial operations candle the eggs, separate out the double-yolks, and sell them to make egg-containing products.
If you are planning to incubate eggs for hatching, it’s generally recommended that double-yolk eggs NOT be included in the incubating eggs. Double-yolk eggs rarely hatch successfully.
I can remember when a double-yolked egg would occasionally turn up in store-bought eggs, but today they’re typically only found in backyard or farmstead raised eggs.
It’s too bad that we see them so rarely; I remember being told they brought good luck. At the very least, they’re a great curiosity for kids.
This is so strange, all of my younger chickens are laying double eggs consistently, like almost every egg I get from these are double yolks. They are fairly young and just started laying maybe a little over a month ago though, so maybe that has something to do with it.
Coral Sinclair says
Hi , one of my chickens who have only been laying for the past couple of months I got from hatch-ling, every couple of days she lays a Double yolker egg, some days only a normal but most times there doubles. It is a lot larger than the others. I just wondered if it is a strain on them doing so. I love having bright yellow eggs, they are fed lots of good vegetables as well as chook feed, can they have grapes/cabbage and corn in a daily feed? My grandchildren enjoy the interaction with them.
Hi Coral, Congratulations on the double yolk eggs! I think it is more difficult for them to lay double yolk eggs because they are typically much larger, but they usually only do it while they are young. Grapes, cabbage, and corn are all ok for them to have in limited amounts – like a treat.
Judith Abel says
Great info thanks. We had hens for years when we lived in UK and had an occasional double yolk egg. We moved to France a couple of years ago and we purchased three chickens a couple of months ago. They were point of lay when we bought them. We are regularly getting double and triple yolk eggs. We have had at least 10 triple yolk eggs. From the information you’ve provided here, it looks like the hen responsible for these won’t be laying eggs for very long! It doesn’t matter though as we always allow them to stay with us for life as they are pets ❤️
I have a hen, about seven months old, who is laying exclusively double-yolked eggs. This started about three weeks ago(she lays one nearly daily). Before this they were normal, single-yolked eggs. I can’t imagine why this is happening so consistently, or that it’s healthy for her. I can’t find information about how this phenomenon effects the health of the hens. I wonder if I should be concerned for her!
Any advice would be sincerely appreciated, thank you so much for your time!
I’ve never heard anyone explain this before. As a kid I was always intrigued by double-yolkers (as we called them). Now I know the ‘why’ behind it!
I bought XL eggs at Trader Joe’s in Chula Vista California and got 11 double yolked eggs out of a dozen. I have picture but can’t figure out how to leave it here. Thanks for the information!
same thing happend to me
Bobby Butler says
I’ve been buying 2 1/2 dozen flats of eggs from a fruit stand for about a year and all of them are double yolk.
In all my 62 years I have cracked open maybe 4 double yolked eggs. However, for the past 5 days in a row so far I have cracked open 9 double yolked eggs. These are out of a 24 pack Kirklands Gage Free from Cosco. There are 2 more eggs in that pack that are taller than the rest and may have double yolks. I have been buying these 24 packs of eggs from Cosco for 1 1/2 years with no double yolks until this week. What do you make of that?
Perhaps it’s time to buy a lottery ticket? Double yolks are said to be lucky 🙂
I cracked open another double yolked egg this morning. This was the sixth day in a row. I think there’s at least one more in this bunch that is double yolked. The ones with double yolks have a slightly odd shape. Lottery ticket, here I come!
Mike Cynar says
Well we had a dozen organic and they are ALL double yoke. MarketZize Organic. What are the freaking odd?
Wilhelmina Reimer says
It was good to know that double egg yokes are good to eat. I just had two separate double eggs in a one dozen carton. Hope it is good luck as you said in your report.
I recently bought a dozen eggs and 6 out of the 12 were double yokes.
I bought my usual “organic” eggs from another store and each one of the ten eggs was a double yoke! Are organically fed hens more likely to produce double yokes?
Hi Philip, I don’t believe organically fed hens tend to produce more double yolks. Most of the traditional commercial eggs are candled to remove any double yolks so they never make it to the store. Your “organic” supplier is obviously letting the double yolk eggs go through. Double yolks are more likely to happen when pullets just start laying, which is right about now for spring hatched chickens in our area. Our pullets that we started in spring are also producing lots of double yolks right now.
Santa Cruz Noe says
Our local market sells double yolks by the dozen. Every one in the carton is guaranteed to have a double yolk.
For breakfast this morning I opened up my regular carton, cracked two eggs, and both had double-yolks; bring on the good luck :’) I’d never seen them before, interesting post – thanks for the information 🙂
Cliff Letts says
In a good way. People misunderstand food value in terms of media scares and such like. Eggs are good ‘end of’ if you have double yolked egg then enjoy and count yourself lucky.
My mother In law buys the double yolk eggs by the dozen from a flea market very often. Is there a certain breed that produce more than others or can the animal be genetically modified to produce double yolk every time.
Pullets that are just beginning to lay, as well as some of the heavy breed birds tend to produce double yolks. The eggs can be candled to tell if there’s a double yolk so that they can be sold as double yolks only eggs. I’m not aware of any way to genetically alter a bird so that they produce only double yolks (and hope it never happens too).
Karen Roothaan says
I have been getting several double yolks each week from my ten hens. I bring them to the local school and they are very popular with the cooking class. The kids get really excited by the double yolks and of course the deep orange color. My eggs won the taste test as well.
Karen, that’s a really good idea for using the double yolk eggs. The kids always love them so much 🙂
Janie Warren says
i love all your great information.
Eric Myers says
I’m not sure I agree with the last paragraph above that states Double Yolked eggs are rare in Store-Bought eggs. My wife and i are consumers, and purchase “Jumbo” brown (locally grown) eggs from the grocery store (Stop and Shop/Price Chopper/etc..) I consistently find double yolked eggs in these purchases. In fact, the current carton we have has had 3 out of the first 5 as double yolked.
Hi Eric, I think you should consider yourself lucky if you can still regularly find double yolks in store-bought eggs, a lot of brands remove any double yolks when they candle the eggs.
We have ameracaunus, jersey giants, buckeye, Plymouth rock and Columbia rock cross. They started laying around the 1st of july and so far we have had 3 triple yolks, and we still get 2 to 3 double yolks daily!! My 5 yr old loves guessing if the egg will be a single or double!
That’s pretty spectacular Leslie, I’ve never seen a triple yolk!
Cliff Letts says
Thank you for a very good article and since reading your article along with conversations with local egg producers, I wrote this: http://lyriclines-lettsy.blogspot.co.uk/2014/07/pullets-prize.html
Have Ameracaunas(easter eggers) that I got as day old chicks in March. They started laying for me back in July. So we decided to have breakfast for dinner the other night and to me and my 7yr old sons amazement the first three were all double yolkers!! Go chickens! Love my girls.
Yup, go girls!
Heather B says
I cooked eggs this morning and both of the eggs had double yolks! It was pretty cool and the only time I’d seen that phenomenon happen!
My hens just started laying about 3 weeks ago. I keep getting one egg every day that is a massive double yolker! I thought I had a special girl. Thats what I call them. “The girls” Anyway they are still special and the article was very informative, thanks. One more note, every morning is like Christmas I can’t wait to get out to the coupe and see what they have for me!!
Congratulations Kelly, and they are all special “girls”!
We just got 3 double yolk eggs in 3 days from the same Welsummer hen. She is the smallest hen and I worry about her laying such huge eggs, 3 days in a row.
I purchased a dozen of jumbo eggs today and of the nine eggs we cooked, five had double yolks. They were purchased at Target and they were delicious The eggs were jumbo and looked very big but they were the best tasting eggs I couldn’t stop talking about how good they were
Glad to know that the double yolk egg is safe to eat & not0 because of a mad Scientists involvement.
Sandra Casey says
IWe buy our eggs from a farm on the central coast of n.s.w Australia .Today I cracked open an egg that contained 3 yolks has anyone else had this happen to them we are still in shock.
Mary Carter says
We had this happen about 2 years ago and I posted it on FB. It was really cool!
Hi. I just received a carton of Simply Balanced cage-free large white fresh eggs from my in-laws a few days ago. Not sure where they bought them but, so far I have cracked 4 out of the dozen and they were all double-yolkers. After reading this I am pretty confident that the others are also. This is totally a first for the family and myself. Still good eating.
So interesting, I just Googled this because I received a dozen eggs from my grandmother’s new hens. One of the hens lays larger eggs than the others; we just cracked open two for lunch today and they were both double yolks!
Hi Liam, that’s great those new hens do tend to produce double yolks!
will a double yolk egg develope and produce twins?
Hi Jerry, I’ve always been advised not to keep double-yolk eggs for hatching because they very rarely hatch.
The yolk is the food source for the growing chick, so no, there would be no twins. The yolk isn’t the baby.
Two yolks would start developing into two chicks, but generally one out-competes the other. One or both always die. Live twins has never happened, or at least it’s never been proven.
I have the luck to eat double yolk twice in my lifetime so far. Am always thrilled!
Jane Putman Sterling says
One of my hens gave us a double yolked egg the other day and I felt blessed! Like she did it especially for me! It was so heavy and quite a bit bigger than the regular eggs she usually lays. I looked around the coop and said out loud, “One of you girls is quite sore today!”
i just bought another tray of double yolked eggs at don victorio’s on 7504 dixie highway in west palm beach. i don’t understand where they get so many from, i hope they don’t treat the hens with hormones. it’s a great fruit and veg market with a lot of organic produce and all their products taste fresh like i remember them to be when i was young. the eggs are delicious!!
Hi Sue, I’m not sure where you are, but it’s most likely you’ll get double yolks if you buy from a local chicken keeper that has pullets that are just starting to lay. The eggs coming from grocery stores/large suppliers have generally been screened to remove any double yolks, so that’s why you would want to go to a local chicken keeper, and pullets (young hens just starting to lay) are the ones that most frequently produce double yolks.
Sue Simmons says
Where can I buy double yolk brown eggs? We used to go to the Hatchery where we used to live and it was fun and great to see all the chickens!!! My family were from England/Scotland and they were the only eggs we ate. I sure miss them! Thank You Sue Simmons
Betty, that’s great – a commercial double yolk (that never happens) and NO cancer.
Betty Price says
I found a double yolk last week in store bought eggs. Never happened before. I buy 100s of eggs each year as a culinary arts teacher. So this demo was unique when this egg popped up!And as far as luck goes, my doctor told me today that my recent cancer scare is just that , a scare!:)
We have 6 New Hampshire red hens who have just started to lay in the past 30 days. We have had several JUMBO eggs with double yolks and also many fragile shelled eggs and some that do not even have a shell. What is the cause of the no shell on the egg? What can be done to prevent this. They already receive calcium pellets with their food.
thanks in advance for any advice.
marilee, when chickens first start laying, it sometimes takes a bit for their systems to get in the egg-laying groove; and double yolk or missing shells are the result. If they’re getting enough calcium, a good balanced feed for laying hens, and plenty of water; then I’d just wait for a bit and see if they don’t settle in.
Thanks for reply lesa! I kinda figured that was the case. I will be patient! The double yolk eggs are HUGE! 😉 Enjoy this website! I know I will learn alot from everyone!
I have 9 pullets & 1 rooster.One of my pullet laid double yolk egg & made my children happy…
One of them had laid egg with 3 yolks too…it amazes us,my pullets are 7 months old.
Susan White says
Hi there… great website, very informative!
We get our eggs from our local butcher (small country town) and you can almost guarantee they will all be double yolkers every time! I don’t know who his supplier is, a local farmer I guess, but they’re awesome!
I don’t recall having any mind blowing good luck though, sorry folks, lol!
Hi, and thanks on the website. I wonder how he gets all double yolks???
Susan White says
Beats me, must ask him who his supplier is, they must always have a supply of young chooks, lol. We’ve bought a whole tray this time, so it will be interesting to see what’s in that one, will let you know!
kasey welch says
my grandparents used to by eggs from this one store in placerville every egg there was a double yolker.
pauline copeman says
I was interested to see your comments on double yolk eggs.
I have been buying eggs at our local boot sale (yes boot sale) we have a farmer who comes and sells his eggs there,
I am caring for a young chicken,(who was hatched by my four year old granddaughter) the chicken in question eight weeks ago was found with a broken leg, So I rushed it to the vet and I now have a chicken with a splint and a bandaged on its leg. Doing nicely I would like to add,
To get it into bed at night I boil it an egg as a treat, and it really loves them,So it seemed a good idea to buy a tray of 20 off this man for boiling
And almost every one so far has had a double yolk. I have never seen so many, They are big eggs though, I will ask next time what breed of chicken he keeps.
So if that is true being good luck, I maybe will be in with a chance of winning the lottery,
Interesting read thank you
Glad your splinted chicken is doing well – I’ve heard of splinting chicken legs but never seen it done. It would be interesting to know what kind of chicken is giving all the double yolks, if they keep doing it, the farmer better go buy a lottery ticket!
I work for one of the Largest egg producers in Australia, we see around 30,00 double yolkers a day, every day. I’ve seen tripple yolkers and and egg with a shell inside another egg.. Never baught a lottery tickets though..might have to.
I was highly astonished the day I saw twin yolk in an egg. I was the one that prepared the boiled Egg for my Daughter. This egg was bought from an open market in my home town but I actually complained why it was so costly.