How hens lay dark brown eggs

A dark brown egg starts out white, like every other chicken egg. In the last stage of shell formation, the hen's shell gland adds a coat of brown pigment. Breeds known for dark eggs simply add a lot more of it. The deepest layers produce eggs that look like milk chocolate or even close to dark chocolate. Crack one open and the inside of the shell is still pale, because the color is only on the outside.

Breeds known for dark eggs

• Marans are the best known. Some lines lay very dark chocolate eggs, while hatchery stock is often lighter.
• Welsummers lay a rich terracotta brown, often with darker speckles.
• Barnevelders lay a deep brown egg, sometimes with a matte finish.
• Penedesencas, a Spanish breed, are known for very dark reddish brown eggs.

Egg darkness varies a lot by line, so if color is your goal, buy from a breeder who selects for it and ask to see eggs from the parent flock.

Why dark eggs get lighter

This is the biggest surprise for new Marans keepers. Dark layers often lay their richest eggs at the start of a laying cycle, then fade as the season goes on. The hen has a limited supply of pigment, and laying often spreads it thinner. Color usually comes back after the molt or a winter break. Age matters too. Many hens lay darker eggs in their first year or two than later on. Stress, heat and illness can also lighten eggs for a while.

The coating can rub off

On very dark eggs, part of the color sits in the outer layer and bloom. A fresh egg can smudge if handled while still damp, and washing can lift a little color. That is normal and does not mean anything is wrong with the egg.

Dark egg myths

• Darker eggs are more nutritious. The shell color has nothing to do with the yolk or white.
• Feeding certain foods darkens shells. Diet affects yolk color, not shell color. Genetics sets the shell shade.
• All Marans lay dark eggs. Many hatchery Marans lay medium brown. Line and selection matter.

Hatching dark eggs

Very dark shells make candling harder. Use a bright light in a dark room, and give it a few extra days before deciding an egg is not developing. The hatch date calculator helps you track timing.

Common questions about dark brown eggs

Which chicken lays the darkest eggs?

Well-bred Marans, especially from lines selected for egg color, are usually the darkest. Penedesencas can be very dark too.

Why did my Marans start laying lighter eggs?

Fading through the laying season is normal. Color often comes back after the molt.

Do dark eggs have thicker shells?

Not because of the color. Shell thickness comes from the hen's health, age and calcium intake.