By Mike Jones, Farmer/Owner of Tierra Verde Farms
There are a lot of differences between eggs, but the differences that typically matter the least are those that you can see. Both size and color of eggs are based on the breed of chicken and the age of the hen.
Egg Color
In general, there are three shades of eggs: white, brown/tan and blue/green. So there are white layers, like the Leghorn from Foghorn leghorn cartoon fame. There are brown egg layers, like the Rhode Island Red or the Golden Buff that we currently raise, and there are blue/green layers like the Ameraucana.
There are hundreds of breeds of chickens but each breed only lays one shade of eggs. When we first started farming I had some Ameraucanas, Leghorns and Rhode Island Reds. It made for a very pretty egg basket (or dozen of eggs with all the different colors and shades). But we kept having customers come up and ask for “brown eggs,” so I would have to run into the back room and start switching eggs in the package so that dozen had only brown eggs. That caused other customers to end up with just white or blue eggs. I would try to explain that the color of the egg shell didn’t have anything to do with flavor or whether they were “farm” eggs, but they just wanted the brown ones.
White vs. Brown Eggs
So how did a brown egg become synonymous with a healthy egg and a white egg with industrial production? It has to do with production.
A hen eats whether she lays an egg or not. Hens that lay more eggs per year are more profitable than hens that lay fewer eggs per year. One of the most prolific chicken breeds is the Leghorn which lays a white egg. The big egg houses all bought and bred Leghorns because they produced the most eggs, therefore were more profitable.
That old backyard farm hen was typically what we call a dual purpose breed. “Dual purpose” meaning they could be raised for eggs or meat (they were a little larger, heartier breed). Most dual purpose breeds lay brown eggs. This barnyard chicken was free to range all over the farm eating grass, bugs, kitchen scraps, and leftover animal feed, giving it all the nutrients to lay a much nicer eating egg than that of the industrial hen kept in a cage.
The whole time the difference wasn’t the color, it was how they were raised. But the association between color and quality was made and still runs to this day even though it is not true. As soon as the big egg houses found out that you would pay more for a brown egg than a white egg, they started raising and breeding brown egg layers in the same confinement houses that the white egg layers. This way they could control their costs and supply you with brown eggs everywhere.
The Process of Egg Coloring
Color is typically introduced into the shell of the egg at the end of the egg formation process. It takes a hen about 24 hours to make an egg. After the contents of the egg are formed she starts to put the shell around it. At the very end of the process in non-white eggs, she will inject the shell with a dye to color the egg as a camouflage against predators that would eat the egg.
You can tell this happens at the end of the egg formation process because most brown eggs have a white inside shell and a brown outside shell. Meaning the dye was injected right before it was laid. As a hen ages, she will begin to run out of dye. So eggs she lays when she’s older will be lighter than eggs she laid when she was younger. Sometimes you will see eggs with speckles on them. This is because excess dye did not get a chance to be completely dispersed around the egg before it was laid.
Size
Size, like color, is dependent on breed and age of a hen. There are breeds of hens that lay large and extra-large eggs, and breeds that lay medium and small eggs. Most hens kept for eggs will lay a large egg when they reach maturity. Most chickens will start to lay when they reach 4-6 months old.
A female chicken that has not started laying yet is called a pullet. When a pullet first starts to lay, it lays a very small egg that will grow in size as she ages. Most hens/pullets that are available for us farmers to buy will take about a month to grow from a pullet (laying small eggs) to a hen (laying large or extra large eggs).
When we start to replace our hens you will see one of two things. We might have pullet eggs for sale, which will just be a dozen of smaller eggs. Or, we might sell a dozen eggs that have a combination of jumbo and medium sized eggs, which will be some eggs from our old hens and some from our new hens.
One of the reasons that we replace hens is because the younger hens lay more frequently. A hen will lay 20% more eggs in her first year than in her second. This will continue to decline as she ages, so it is very difficult to keep hens profitable for much more than two or three years.
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About Mike Jones
Mike Jones and his wife are the owners of Tierra Verde Farms located in Deerfield, Ohio. They have been in operation since 2010. On their farm, they raise grass-fed beef and lamb, pastured pork, chicken, turkey, and eggs. They also make honey and maple syrup. Their farm philosophy is simply to farm holistically – marry the priorities of the land, the livestock, the farmers and our nutrition. Mike is a weekly attending vendor at our farmers’ markets and Tierra Verde Farms is also a mentor farm for our New Farmer Academy.