Is yolk color is no longer a great indicator of the egg's nutrition?

It used to be true that, if your egg yolks were darker in color, then the better the egg's nutrition. Conscious consumers of the past would look for that deep orange yolk and stray away from lighter yellow yolks. It's sad, but this simply isn't the case anymore.

First, let's examine the past. 

Yolk color used to matter, because when birds were pasture raised, they ate a variety of foraged foods like grasses, seeds, and bugs. These foods naturally contained carotenoids (fat-soluble pigments) that made the yolks darker. 

These truly pastured eggs offered more nutrition (more vitamins, omega-3s, antioxidants, etc) because the birds were naturally healthier. They had access to fresh air and exercise. They didn't need drugs to survive. They ate a natural diet. They were allowed to be... well... chickens. The health of the bird has a direct impact on the nutrition of the egg. 

On the flip side, birds that lived indoors on mega factory-like "farms" ate a diet of mainly wheat, corn, soy. These foods are low in carotenoids, and therefore indoor chickens produced lighter colored yolks. Since they weren't as naturally healthy, the eggs were less nutritious.

But things have changes. Let's take a look at the present.

It's sad but true. Big ag has caught onto consumer demand for "organic" and "natural" foods. They are altering food and putting a "green sheen" on the visual appearance and the labels to capitalize on these trends.

When it comes to eggs, did you know that many mega egg producers now add colorants to their feed to make the yolks superficially orange? 

Here are some things that might be added:

This is why yolk color used to be a great indicator of egg quality and nutrition, but not anymore. You cannot trust cheap store-bought eggs with orange yolks. 

The only way to truly know the quality of your eggs is to know your farmer.

Not our farmers! No greenwashing here! Our egg farmers who produce OUR CORN & SOY FREE EGGS never put colorants in their feed. 

And that means that the yolk color will vary with the seasons, the weather, the age of the flock, etc. Varying eggs are a sign that you're getting real deal, pasture raised, naturally healthy eggs! Personally, if my food doesn't have slight variation from time to time, then I question how natural it really is.

But wait, is there a health difference between pastured yellow and orange yolk eggs?

I was curious about the same thing. So, I sent two cartons of our eggs, one with orange yolks and one with yellow yolks (along with some other samples that weren't ours for comparison), to a lab for nutritional testing.

And the egg test results say... there's basically no nutritional difference based on yolk color alone. 

For 95% of the 100+ tests done, the results were exactly the same. They look like this:

The difference happened with vitamins, and the results say that the yellow yolk eggs were more nutritious than orange yolk eggs. Such a surprise!

Dr. Van Vliet, the scientist who did the testing, noted that Vitamin B2 (riboflavin) was a lot higher in the yellow yolk eggs. Riboflavin is a yellow colored compound, and this is what's likely making the yellow yolks yellow. So cool!

Different plants have different pigments, and that's what affects the yolk color.

The pastures our laying hens are in are diverse. There's a wide variety of plants. And, different sections of each pasture might have higher or lower concentrations of different things. 

Plus, the hens are choosing what to forage for (we can't force it). They might pick different plants based on what they're in the mood for, the growth stage of the plants, the time of the year, etc. 

And then there's winter, when there's nothing to forage for and our hens spend most of their time indoors. 

What the hens eat has a direct affect on the yolk color. Here are just a few examples:

Dandelion and plantain are both high in Vitamin B2, so we're thinking that the hens with the yellow yolks were eating lots of those plants.

We love having the yolk color indicator of what the hens are eating. It helps us constantly get better at farming and producing the best food for you!

What matters most when it comes to the most nutritious eggs? The farming practices and the feed ingredients.

Birds foraging on well maintained pasture AND eating a quality feed with thoughtful ingredients, ratios, and preparation make the most nutritious eggs.

Our hens are fed GMO-free, corn-free, and soy-free feed. The feed contains a specially formulated blend of of oats, rolled wheat, peas, alfalfa hay leaves, barley, fishmeal, sesame meal, raw liquid goat whey, vitamins, minerals, and probiotics. 

The way the feed is mixed ferments it (and adds probiotics, too). It's like it's pre-digested, making all the nutrition bioavailable for our hens. And that's why our eggs had such great nutritional results. That includes a 4:1 omega 6/3 ratio and low PUFAs!

And the feed suppliers aren't done yet. Just like our farmers, they're constantly improving.

What matters most to you when purchasing eggs? Were you duped by the yolk color?

I'd love to hear from you. Comment below or contact us.

*Originally posted on 9/22/23. Updated on 1/14/25.