- In general, the color of an egg has nothing to do with its taste or nutritional levels.
- The eggshell color comes from a pigment that is part of the overall genetic make-up of the hen that lays the egg. While you can't necessarily predict the color of the eggshell by the color of the feathers, there is an connection in the color of the earlobes. Hens with white earlobes lay white eggs. Hens red earlobes lay brown eggs. Who knew hens had earlobes?
The smaller white patch above the big round white patch is the earlobe.
(Photo from My Pet Chicken)
- In general, consumers in the Northeast of the US prefer brown eggs, so most hens there are Rhode Island Reds, which produce brown eggs. Consumers in other parts of the country prefer white eggs, so most hens used elsewhere are White Leghorns, which produce white eggs.
- Brown eggs generally are more expensive because the Rhode Island Reds are bigger birds and eat more, which means it is more expensive to maintain them.
- Chicken eggs are not just white or brown. They can also be blue or green or speckled, depending on the breed of hen.
- Organic eggs do not impart greater nutritional benefits, but they are produced by hens who are fed grains that have not been treated with commercial pesticides or fertilizers. The idea is that hens given organically grown feed aren't ingesting lots of man-made chemicals, which then could be passed on to you.
- Free-range eggs are produced by hens that are not kept in cages but live on an open floor, and not necessarily outside. These eggs are produced on a seasonal basis. Again, free-range eggs do not have any immediate nutritional benefits.
- The overall size and weight of an egg is an indicator of the health, breed, and maturity of the hen that laid it. Healthier, larger, and older hens produce larger eggs. Poor nutrition, stress, heat, and overcrowding can make hens produce smaller eggs.
- Similarly, the thickness of the egg's shell is determined by the age of the hen and the hen's nutrition. The healthier the hen, the thicker the shell. At the same time, older hens produce larger eggs. Larger eggs have a thinner shell, just because there's more area to cover. If a larger egg has a thinner shell, that may have more to do with the age of the hen rather than its health.
- So if the eggshell is thicker, it's not because it's a brown egg. It's most likely because the hen is healthier, or older, or living under better conditions.
Some egg tips:
- The shell of an egg allows air to permeate it, so the chick inside can grow. The same is true of the eggs in your refrigerator. The longer you've kept the eggs, the more air will be inside them. You can check the amount of air in the egg by holding it up to the light (it won't work for brown-shelled eggs because they're too dark). A grade A egg is sold with an air pocket 3/16 of an inch deep. If an egg is very old, it will float in water while still uncracked because it has so much air in it.
- There's a natural coating called a "bloom" over the egg, which keeps bacteria from getting in through the tiny holes in the shell. When eggs are washed -- which they all are at the packing house -- that bloom gets washed off. The packers then apply a thin coating of oil to replace the bloom. If you wash your eggs before you use them, you get rid of the oil coating and leave the egg again vulnerable to bacteria. So don't wash your eggs.
- Generally, eggs are still good up to four weeks after they've been packed. Most egg cartons will display the packing date, as a number from 1 to 365. Most cartons also display an accurate expiration date.
- You may find, in a rare occurrence, a blood spot on a yolk. Blood spots do not indicate fertilization. They do not happen often, but they are caused by the rupture of a blood vessel on the surface of the yolk when the egg is formed. Most eggs with blood spots are removed during inspection, but some do slip through. A blood spot will not affect the flavor or quality of the egg. In fact, it is an indicator of freshness, since the blood spot is diluted as an egg ages. You can remove the blood spot with the tip of a knife.
Ask Yahoo, "What's the difference between white eggs and brown eggs?" May 23, 2000
Ohio State University Extension, Smart Stuff with Twig Walkingstick: Brown Egg, White Egg, January 11, 2004
PoultrySolutions.com, Knowledge: eggs
Raley's and Bel-Air Health Notes: Eggs
Hormel Foods: Egg shopping guide
Incredible Edible Egg: Basic Egg Facts