Eggshell White
Just thought I’d head this question off at the pass: what about eggshell color? What determines that? The answer: the breed of the hen. Different types of chickens lay eggs of different colors. I know there are a lot of folks out the under the impression that a brown shell is somehow indicative of a “less processed” egg, but that isn’t so. Brown eggs can come from a commercial egg farm just as easily as white ones (and many do).
Contrary to popular myth, chicken eggshells are never, ever bleached. The reason for this is quite simple: eggshells are porous. The most an egg processor will do to an eggshell is apply a thin layer of oil or wax to replace the natural mucous layer that comes off when the egg is washed. The layer helps keep out contaminants and extend the egg’s life.
One last thing about eggshell color: it’s possible to predict the color of the egg a hen will lay based on the color of folds of skin on the hen’s face — the so-called “earlobe.” Chickens with white earlobes tend to produce eggs with white shells while chickens with red, brown or blue earlobes tend to produce eggs with brown shells.
Having grown up around Rhode Island Reds and Leghorns, I was familiar with the different colored eggshells, but until I read your post I never thought to ask the next logical question – how does skin color relate to egg color? It must have something to do with the chicken innards making some extra melatonin (or the hen equivalent) to pass along to the eggs. I guess it makes evolutionary sense that if the color of hen helps it hide, eggs of the same color should also blend in well. Now if we could only explain robin eggs…
I’m over my head there, Ron. But I’ll ask around! Thanks for the note!
My grandmother used to raise Dominique (also called Dominicker) chickens. They laid brown eggs. I’ve since discovered that the Dominicker is a rather rare breed of chicken. They have them at the Homestead over at Land Between the Lakes
I’ve noticed that most of the chefs on the Food Network use brown eggs. I wonder why.
I think they’re just hipper. The give off the look of authenticity. That’s my theory, anyway!
Apparently the colour of egg shells comes from pigments called porphyrins that come from the breakdown of haemoglobin. Typically these colours are brown and green-blue and this tends to be genetic and dependent on the breed of chicken rather than environmental (so free-range hens don’t necessarily lay brown eggs). In a somewhat irrelevant aside, Joseph Needham of the vast “Science and Civilisation in China” started out life as a biochemist and worked on pigments in eggshells.
Interesting stuff, Craig! Thanks!