Australians are no strangers to enjoying a good egg or two, whether it’s for breakfast, in a salad, or as part of a delicious pavlova. But have you ever cracked open an egg and been taken aback by the colour of the yolk? It’s a common experience that can leave many of us wondering if there’s something wrong with our eggs or if the colour signifies something important about their quality.

The truth is, the colour of an egg yolk can vary widely, and it does indeed have a story to tell. Let’s delve into the fascinating world of egg yolk colours and discover what they mean for the quality, taste, and nutritional value of your eggs.

Egg yolks can display a palette of colours, ranging from a light, almost white hue to a deep, blood-red orange. While it’s rare to encounter the extremes in a typical grocery store, you’ll likely find yolks that are bright yellow or pale orange. 

The colour of an egg yolk is primarily influenced by the hen’s diet. Poultry experts use a tool called the DSM Yolk Colour Fan, which is a 16-scale colour index, to measure and categorise yolk colour. On this scale, a pale yellow yolk is rated as a 1, while a deep orange yolk is a 16.

The factors influencing yolk colour

Several dietary components can affect the shade of an egg yolk. According to experts like Poultry Management Assistant Professor Sunoh Che, DVM, PhD, these include:

1. Carotenoids: These plant pigments, such as lutein from alfalfa meal and zeaxanthin from marigold flower extract, significantly impact yolk colour. They are responsible for the yellow-orange pigmentation.

2. Corn: The amount of corn in a hen’s feed can also influence how yellow the yolk is. Hens fed a corn-based diet typically produce the yellow yolks commonly seen in grocery stores.

3. Xanthophyll: This yellow compound is found in leaves and grains and varies in concentration among different plants. The specific types of xanthophyll-containing plants a chicken consumes can affect yolk colour.

4. Environment: Hens that forage on fresh grass and pasture reportedly have a more varied diet, including proteins from bugs and additional carotenoids and xanthophyll from plants, leading to more vibrant yolk colours.

Yolk colours and their meanings

According to Jen Houchins, PhD, RD, director of nutrition research at an egg nutrition centre, the shade of an egg yolk can suggest several things:

1. Pale yellow yolks often come from hens fed a diet rich in wheat, barley, or white cornmeal.

2. Bright yellow or yellow-orange yolks usually indicate a diet with plenty of corn and/or alfalfa meal.

3. Orange yolks can result from adding marigold petals or red pepper to the feed, or from a diet that includes foraging on diverse plants and insects. Seasonal changes and the hen’s age may also influence yolk colour.

Nutrition, flavour, and yolk colour

While many people assume that a darker yolk means a more nutritious egg, Dr Che says this isn’t necessarily the case. The nutritional content of an egg, including vitamins A, D, E, and K, ‘depends more on the hen’s overall diet, health, breed, age, and environment.’

However, darker yolks may indicate a higher concentration of carotenoids, which are beneficial for eye health and may reduce the risk of certain diseases.

Meanwhile, when it comes to flavour, eggs from hens with access to a varied diet, including bugs and plants, tend to have richer and more flavourful yolks, says senior food editor Breana Killeen.

While feeds can produce orange yolks, the taste doesn’t compare to yolks from ‘happy hens’ that forage naturally.

For the best-tasting eggs, look for those labelled as pasture-raised. Purchasing directly from a farmers market or a farmer could ensure you’re getting eggs from hens that have enjoyed a natural, diverse diet.

In conclusion, the colour of your egg yolk can tell you a lot about the hen’s lifestyle and diet. While it doesn’t necessarily reflect the egg’s nutritional value, it can give you insights into the quality and taste of the eggs you’re about to enjoy. 

We’d love to hear from you, our YourLifeChoices readers. Have you noticed differences in egg yolk colours in your kitchen? Do you have a preference for a certain yolk colour when it comes to taste or cooking? Share your experiences and thoughts in the comments below.

Also read: The sunny side of nutrition: Eggs could boost heart health and longevity