When I was a kid we used to associate brown eggs with free-ranging birds on the farm and white eggs with those bought at a store and sourced from commercial operations. Some folks still believe that egg shell colour is indicative of where the birds were raised. It turns out, that egg shell colour, is dependent on genetics and has nothing to do with small scale vs factory farms.
Forty years ago, I went to Belize as a teenager. I remember ordering eggs for breakfast and both the albumen and yolk were almost the same colour: an off-putting off-white. And why wasn’t the yolk a sunny yellow or deep orange? Because those hens were free-ranging, eating whatever scraps they could find which had an impact on the colour of their yolks.
Egg shell colour is influenced by genetics, but the interior of the egg is a reflection of what a hen has eaten.
Around the world different cultures value different qualities in chickens. In China and parts of Asia, the black meat of Silkie and Ayam Cemani chickens is valued, while most North Americans might be put off by the sight of it.
The colour of egg yolks is also influenced by cultural preferences. Asians like an orange to red yolk, Europeans prefer golden yellow. If you, or your customers, have an ideal yolk colour you can try to achieve it by tweaking their feed.
A USDA study concluded that yolk colour has no impact on nutritional value. All yolks contain less water, more fat and less than half of the protein of an egg white. On the other hand, most of an egg’s vitamins and minerals are found in the yolk: iron, vitamins A and D, phosphorus, calcium, thiamine and riboflavin.
Yolk colour is created by two components: a yellow base color and red to deepen it. Lutein and zeaxanthin are the carotenoids that provide yellow, canthaxanthin provides red.
Pale Yellow: a result of lower amounts of xanthophylls, such as wheat, white cornmeal or barley.
Golden Yellow to Mid-Orange: predominantly green plants, yellow corn, alfalfa and other plants with xanthophyll. This is the typical yolk colour see in grocery store eggs.
Deep Orange: If you want to deepen the colour of your eggs then feed carotenoid-rich feed: apricots, beets, broccoli, canteloupe, carrots, corn, dark leafy greens (collards, kale, mustard, turnip), marigold flowers, nectarines, peaches, peas, pumpkin, romaine lettuce, squash, sweet potatoes, tangerines, tomatoes and watermelon.
Green: I’m not referring to Dr Seuss’ Green Eggs & Ham, but the greenish colour around the outside of hard boiled yolks. It might not look that appetizing, it’s just a result of sulfur from the albumen reacting with iron on the surface of the yolk. To avoid the greenish tint, don’t over boil your eggs and rapidly cool them after cooking by placing in an ice bath or under cold running water.
Tips On Achieving The Perfect Yolk
- Grains lighten yolk colour, grasses darken them
- If your yolks aren’t dark enough add more carotenoids.
- Start feeding your pullets pigment influencing food several weeks before they start to lay.
Credit: Poultry World Featured Image: Matthew French