The aesthetics of eggs 🥚
This edition: Does egg yolk color really matter? What about shell color? And what does a “heritage” egg mean, anyway?
PHEW, this week’s email was a doozy. I did a bunch of research into all. things. eggs.
I realize I rather like this semi-obsessive knowledge gathering. But do let me know your thoughts—if you’d like more or less information, or if you just want to drop an idea or two for future topics. Would love to hear from you.
Have a great week, folks! Be well.
—Connie
P.S. I drew a diagram of an egg that I ended up not really needing for this post, but here it is anyway:
The aesthetics of eggs
Aesthetics: adj.—of or relating to perception by the senses (obsolete usage); n.—a conception of what is artistically valid or beautiful
Before we dive into what makes (chicken) eggs so darn good, I wanted to start with the importance of aesthetics and why it matters.
Why are aesthetics important?
How we interact with the physical world is part of what it means to be human. How we see, taste, smell, hear, feel the things around us can affect our mental state—good and bad.
Enjoying the aesthetics of something doesn’t mean you’re shallow. It just means you have an appreciation for the physical realm.
When something pleases our senses, it can make us happy. Calm.
Why does it matter if eggs are aesthetically pleasing?
#1 - Eggs are magical
For one, let’s reframe the way we think about eggs! For such a mundane food, I think it’s easy to forget that we rely on another living being (or, really, a lot of other living beings) for this nutritious source of protein.
This is an homage to our feathery ladies and the hard work they put into egg laying.
#2 - The better the aesthetics, the more nutrient-dense they are
Secondly, the look, feel, and taste of eggs should please the senses (exceptions made for those who don’t like eggs or are allergic, of course)! And the better they look and taste, the more nutrients we’re getting out of them.
I’ll explain in more detail why that’s the case.
But to start, let’s look at the exterior: the eggshell.
Does the color of the eggshell matter?
Short answer? No.
Long answer? No.
The only thing that determines eggshell color is the breed of hen. Some breeds can lay multiple colors—and a single hen may be capable of laying eggs in a range of colors, depending on factors like weather and diet.
And even with all these different colors of shells, there’s no noticeable difference in nutritional value.
So brown-shelled eggs are not necessarily better than white, especially if all other factors are the same.
So why do we mostly see white and brown shelled eggs in the store?
With the exception of the rare pack of heritage eggs that show up on the refrigerated shelves, most white eggs in the US that you’ll find in stores are laid by the Leghorn variety.
Why Leghorn? Because they’re one of the most productive, with a single hen laying anywhere between 280-300 eggs per year. Given that it takes a hen 24-26 hours to produce an egg and only resting for about 30 minutes between laying and production, they’re basically working nonstop.
Apparently brown eggs were more costly to produce because those hens were larger, required more feed, and produced less than those that laid white eggs; but these days, the costs and production rates are pretty much the same.
An average Lohmann brown-laying hen, for example, is just as productive as a Leghorn white-laying hen, laying 270-300 eggs per year.
How many chicken breeds exist?
60+ breeds are officially recognized by the American Poultry Association, and many, many more exist globally (such as the all-black Ogye).
But the thing is, with industrialization, our food systems turned into monocultures, where we focus only on one or a small handful of ultra-productive species. As a result, at least in the US, we’ve relied a lot on only a few breeds of hen, meaning other, usually less productive, breeds are cast aside.
It’s a shame, because if we let these breeds die off, we lose out on some beautifully colored eggs too!
What color eggshells are there?
We’ll start with a fun fact: similarly with all bell peppers starting off green, all eggs, as they form in the hen’s oviduct, start off white-shelled.
Of course, we know about white and brown eggs, but there are also:
Pinks/creams
Greens
Blues
How do eggs get their color?
It’s all during the egg production, when it’s in a hen’s oviduct. Depending on the breed, the pigment is added during different parts of the laying process.
Brown eggs
Pigment: Protoporphyrin, a heme compound (related to blood)
When it’s added: Late in the process
Result: The brown color shows up on the outside but doesn’t have a chance to penetrate the eggshell. That’s why the inside of a brown egg is still white and not brown.
Blue eggs
Pigment: Oocyanin, a compound related to bile production
When it’s added: Early in the process
Result: Because of how early the blue color is added, it has a chance to penetrate through to the inside of the eggshell.
Green eggs
Pigment: Oocyanin & protoporphyrin
When they’re added: Early and late in the process, respectively
Result: The outside and inside of the egg is blue early on, since the blue pigment had the chance to penetrate through the eggshell. Then later on, the outside of the egg turns green once the brown pigment is layered over the blue.
Pink eggs
Pigment: Protoporphyrin
When it’s added: Late in the process
Result: Though very similar to how brown eggs are colored, the outside of pink eggs are only lightly colored with protoporphyrin while the inside is white. Because the porphyrin is heme-based, it’s no surprise that a white egg with a warm brown (with red undertones) would result in a pink shell.
If the color of the egg doesn’t affect nutrition, what does?
Just two things:
The hen’s diet
The hen’s lifestyle
But these two things can greatly affect the egg’s composition, from its shell thickness to the viscosity of the whites to the color of the yolk. And with these different factors, they’re clues to how nutrient-dense an egg is.
About the yolks—is the color impacted by what a hen eats?
Yes! We can learn a lot about what a hen ate by the color of the yolk it produces.
Deep orange: most common among pasture-raised hens
Diet: varied among grasses, seeds, insects, worms
May also come from: orange peels, algae, marigold flowers, paprika, safflower, red pepper
Mid-orange to gold: may also be pasture-raised, or those with supplemental feed
Diet: alfalfa, greens, yellow corn, and other plants with xanthophylls pigment (one of two carotenoids, like those found in orange vegetables like bell peppers, squash)
Pale yellow: caged hens with no foraging
Diet: corn, soy, wheat, barley, white cornmeal
Okay, so which eggs are better for me?
Generally speaking, what you want to look for are cartons that say they’re (in order of importance, but ideally all of these):
Pasture-raised
Humane- or welfare-certified (done by a 3rd party)
Certified organic
If you live in an area where access to these eggs are difficult or cost-prohibitive, then look for ones that claim (in order of importance):
Free-range, especially if coupled with a humane or welfare certification
Omega-3 enriched: The omega-3s will help offset omega-6, which we get too much of nowadays. These may be more expensive than conventional eggs, though your store’s pricing may vary.
Are there any labels that I should know about or avoid?
Yes, only because there are a ton of marketing labels out there that are dubious at best and misleading at worst. Even labels like “organic” that are regulated by the USDA (U.S. Department of Agriculture) can be downright inaccurate, if only because there may not be any third-party group to audit farms’ claims.
All-natural or 100% natural
Verdict: Useless
Why: At least in the US, this label only means that there were no additives, like flavors, brines, or coloring. It’s kind of like saying sugar is a low-sodium food—not helpful.
Organic
Verdict: In US, somewhat useless; in UK, somewhat useful
Why: Despite regulation in the US, the “organic” label sets criteria for general living conditions and organic diet, but there’s no requirement for humane treatment or access to outdoor space. There’s also no guarantee the organic diet covers all the hens’ nutritional needs.
On the other hand, in the UK, the “organic” label means hens are also free-range, which means they have daytime access to grassed or vegetative outdoor space.
Cage-free
Verdict: Useless
Why: Hens are not confined to cages but may still be shoved into buildings or rooms with too many other hens for a comfortable living situation. They also typically lack access to outdoor space and are not likely treated humanely.
Free-range
Verdict: In US, not very useful; in UK, somewhat useful
Why: Though US regulations say hens must have continuous access to outdoor space, they may only have access to a dirt lot, which defeats the purpose of true “free-range”—allowing hens to nibble on grasses and forage for bugs.
In the UK, free-range is a bit better, specifying access to grassed or vegetative outdoor space. Plus, there are max capacities set for their indoor living situation.
No antibiotics
Verdict: Somewhat useful
Why: This one’s a bit tricky. Antibiotics are not all bad, and they’re used to treat sick hens. But! Antibiotics can be used to encourage growth and weight gain in hens—surely considered an abuse.
While we should discourage antibiotics used for growth, it may be worth allowing farmers to keep their hens healthy instead of delaying or refusing treatment.
No added hormones
Verdict: Misleading
Why: In the US, hormones are prohibited (i.e., illegal) to give to chickens. If this claim is made, the packaging must include a disclaimer to say that regulations prohibit use of hormones anyway.
Vitamin enhanced / omega-3 enriched
Verdict: Useful
Why: Hens may be given different foods in their diet to supplement and pass along certain vitamins into their eggs.
Certified humane / Animal Welfare Approved
Verdict: Very useful when used in conjunction with certification from HFAC (Humane Farm Animal Care, a nonprofit) or AGW (A Greener World, a nonprofit)
Why: Typically means that the hens have been raised and given a lifestyle that’s comfortable.
Pasture-raised
Verdict: Very useful when used in conjunction with HFAC certification in US
Why: Hens are raised outdoors, weather permitting. They’re moved from one area of grasses and vegetation to another on a regular schedule so that the depleted area can regenerate for the next round.
Access to pasture / outdoor access
Verdict: Misleading
Why: This phrasing is typically used when a farm hasn’t received HFAC certification but wants to benefit from the prestige of “pasture-raised” labeling without actually using it.
Vegetarian-fed
Verdict: Harmful
Why: Hens aren’t vegetarians; they’re omnivores, eating grasses and bugs when given the chance to forage. So to say that they’re given vegetarian diets likely means they’re getting soy or corn meal. The yolk from these hens tend to be pale yellow, being deprived of the foods they actually eat.
Lion mark (UK only)
Verdict: Mostly useful
Why: In the UK, the presence of a lion stamped on the egg carton means that the hens that laid the eggs were vaccinated against salmonella. While there are conflicting studies on whether vaccination helps prevent infection or not, it’s a costly (and optional) program that seems to have a positive impact on protecting farmers’ flocks.
Wait, what about heritage eggs?
Heritage eggs come from heritage chicken breeds.
In the US, the American Poultry Association (AMA) recorded all the chicken breeds starting in the late 1800s. With industrialization favoring only a few breeds, diversity was (and still is) in danger.
For eggs to be marketed as heritage, as per the Heritage Poultry Conservancy (there doesn’t seem to be federal regulation in using “heritage” as a label), the chickens:
Must be one of the AMA-recognized breeds
Mate naturally
Stay healthy, productive, pasture-raised
Hens to lay eggs for 5-7 years
Roosters to sire for 3-5 years
Grow at an appropriately slow rate
I’ve only found heritage eggs in the store once, from Happy Egg Co. And they were the loveliest tasting—extra creamy, deep orange yolks; plus, the speckled dark brown and blue eggshells were a visual treat!
If you ever see them, don’t hesitate to grab a carton and try for yourself. You won’t be disappointed.
I didn’t know eggs could get so complicated.
Me neither! It’s been fun researching all there is to know about eggs. There’s still a lot about them that I didn’t cover here, but I think this is about as deep as any normal-ish person might want to go.
What did you think about this first deep-dive?
Do you have any questions about eggs that I didn’t cover here? Any corrections or clarification points needed?
Let me know!
Next up
What’s next? I’d love your help picking the next topic!
For some more context on each of the poll options:
Ecology of coffee: Are we doomed to a shortage? Are there environmentally friendly alternatives that we should consider?
The ethics of fast fashion economics: Does cheap labor in textiles create financial opportunities or destroy development of labor markets? What are the alternatives for labor in these areas and are they better or worse?
Other (reply or leave a comment!): Let me know if you have any particular topics you’d like me to cover that aren’t the two above. I’d love to hear from you!
Go back to the old newsletter style: Did you prefer how I wrote the newsletter before? Check out a previous edition 👇
