We’ve kept chickens for nearly eight years. We love them. Their poo on the doorstep occasionally tests the relationship, but we still love them. When one dies, we hold a little funeral.

Spend enough time around chickens and you get to know the characters behind your breakfast. You also discover things that rarely feature on an egg box. The excitement when ours find a dead frog, for example. They will fight over it.

That surprises people. We have become so accustomed to the image of a hen pecking grain that we can forget she is an omnivore, with an appetite for insects and other small creatures as well as seeds and greenery.

Watching them makes the supermarket egg aisle feel rather strange. All those boxes promising something slightly different, with very little room to explain the life behind the shell.

What does free-range actually mean? Are organic eggs also free-range? Does a dark orange yolk tell us anything useful? And how much space does a hen really get?

Eggs are wonderfully nutrient-dense food. Once you know the characters who lay them, you want the box to tell you something about their lives: what they eat, where they roam, and how they are cared for through the seasons.

Organic versus free-range eggs: the quick answer

In England, free-range describes a production system with outdoor access under specified conditions. Organic adds requirements covering feed and husbandry, including lower indoor stocking density. Organic laying hens also have outdoor access, although compulsory disease-control restrictions can affect this. Neither label means every bird spends her day roaming lush pasture.

Pasture-raised is not a separate numbered egg-production category in England. Ask the producer what it means on their farm. British Lion and RSPCA Assured are assurance schemes with different purposes; the production method still matters.

To understand an egg, we need to look at the hen, her surroundings and her feed together.

The humble egg is a remarkable piece of biology

Crack an egg into a bowl and pause before whisking it.

The shell has thousands of tiny pores and a protective outer coating called the cuticle. Inside are shell membranes, layers of egg white and the yolk, held in position by twisted strands called chalazae. The familiar breakfast egg is usually unfertilised. A hen does not need a cockerel to lay one.

It takes roughly a day to assemble this package, much of it spent forming the shell. Its apparent simplicity hides a considerable biological effort.

Eggs supply high-quality protein, vitamin B12, riboflavin, selenium and iodine, alongside other nutrients. The yolk contains fat, phospholipids and much of the egg’s micronutrient richness. [1]

One particularly interesting nutrient is choline. We use it to make phospholipids that help form cell membranes, and acetylcholine, a chemical messenger involved in muscle control, memory and other nervous-system functions. [2]

Our cell membranes contain a phospholipid bilayer: a dynamic boundary that allows cells to maintain their internal environment and communicate. The nutrients in ordinary foods contribute to the materials that make these systems possible. There is something rather beautiful about that connection between breakfast and biology.

Why do chickens lay fewer eggs in winter?

Keeping chickens brings the seasons into your kitchen. You notice it in how many eggs you collect.

As the days shorten, ours lay less. Daylight helps regulate a hen’s reproductive cycle, so the changing light outside becomes part of what appears on our plates. Autumn can also bring the moult, when hens replace their feathers and laying often slows or pauses. In colder weather, keeping warm uses more energy. Age, breed, nourishment and health all influence the eggs a flock produces. [3, 4]

An egg takes on a different meaning when you see that effort. The hen making it is also maintaining her own body, growing feathers, keeping warm and going about her day. Her needs change with the season, just as ours do.

Commercial producers can use timed lighting to encourage laying through the shorter days. That helps maintain the supply we have become used to, while making the hen’s seasonal rhythm less visible from the supermarket aisle. Proper darkness and rest still belong in her daily care. [4, 5]

There is something lovely about knowing an animal well enough to notice these changes. You begin to see the care behind the food, and to appreciate the eggs that arrive.

What do chickens naturally eat?

Watch chickens searching for food and you see how much interest they take in the ground beneath their feet. They scratch through leaves, peck at greenery and pursue small things that move. Seeds, plants and invertebrates are all part of their feeding world. [6]

The excitement over that frog makes rather more sense once you remember they are omnivores. Finding food occupies their attention as well as filling their crops.

This is one of the pleasures of keeping them: seeing ordinary ground become somewhere full of possibilities. A sheltered patch with vegetation and material to scratch through offers a hen something to explore.

Modern laying hens have substantial nutritional needs, shaped by breeding for egg production. Protein, energy, calcium and other nutrients support both the bird and the eggs she makes. A suitable complete ration can provide that dependable nourishment alongside opportunities to forage. [4, 7]

I want us to look at both parts of that picture: the quality of what goes into the feeder, and the life she can lead around it.

Why are commercial hens fed soya, cereals and oils?

The feed behind a supermarket egg may have travelled much further than the hen herself.

At commercial scale, ingredients need to arrive in large quantities, store well and deliver predictable nutrition at an affordable price. Wheat is prominent in British laying-hen diets. Soya meal, produced when oil is extracted from soya beans, supplies concentrated protein. Added oils provide energy and can influence the fats in the yolk. [7, 8]

Those ingredients help a producer maintain a consistent ration. As someone buying the eggs, I also want to understand their origins. Where were the crops grown? How were they processed? What else does the hen eat?

Soya brings questions about land as well as feed. Some supply chains are associated with deforestation and the conversion of other natural habitats. Knowing the source matters, and a farmer’s choice of feed can connect our breakfast with land thousands of miles away. [9]

Processing and storage deserve attention too. Raw soya contains compounds that interfere with digestion; appropriate heat treatment reduces these. Research comparing fresh and oxidised feed fats has also found poorer laying performance with oxidised fats, including animal and vegetable sources. The ingredient, its quality and how it has been handled all matter. [7, 10]

For someone seeking a more locally grown ration, or wishing to avoid soya altogether, a conversation with the producer can be revealing. Ask what they use instead, where it comes from and how they meet the flock’s nutritional needs.

Does soya in chicken feed affect the eggs?

Some compounds in feed can reach the egg. Soya contains isoflavones, which have hormonal activity, and researchers have demonstrated transfer into yolks using isoflavone-enriched feed. That experiment tells us transfer is possible; its concentrated ration cannot establish hormonal harm from eating ordinary eggs. [11]

Crop treatments raise another question. In a controlled feeding experiment, glyphosate and its breakdown product AMPA reached eggs, with concentrations reflecting the hens’ exposure. The study found no clear adverse effects on the measured mineral status, welfare indicators or overall performance, and did not assess health effects in people eating the eggs. [12]

These findings make feed sourcing and testing worth asking about. A non-GM crop can still have been treated with pesticides, so the growing practices deserve a question of their own.

GM feed, organic eggs and soya-free eggs

In the UK, eggs from hens fed GM feed do not have to carry a GM label. The feed has its own labelling requirements, but that information does not automatically follow the egg to the shop. [13]

That leaves something important out of the shopper’s view. Free-range describes the production system and does not, by itself, rule out GM feed. Organic standards prohibit GM feed, although organic hens can still receive organically grown soya. [14]

Organic and soya-free answer different questions. If you want eggs from hens fed without soya, ask specifically about the ration. That preference can sit alongside wanting traceable ingredients, thoughtful land use and room for the hens to forage.

The whole feeding story matters. A well-nourished bird with a varied environment is the picture I want to bring back into view.

Does a hen’s diet change egg nutrition?

The egg carries something of the hen’s diet within it. Controlled research has shown that changing feed oils changes yolk fatty-acid composition. Linseed oil, for example, can increase omega-3 content. [8]

Sunlight has a part in the story too. Researchers have found higher yolk vitamin D in hens exposed to sunlight under experimental conditions. Feed, season and the exposure birds actually receive help shape the result. [15]

This is a beautiful connection to consider: the bird, her food and her surroundings contributing to the egg we bring into the kitchen. It also helps explain why a label alone gives us an incomplete picture. If a producer promises a particular nutrient level, testing the finished eggs gives that claim substance.

Are orange egg yolks healthier?

A rich orange yolk is appealing. Crack one into a bowl and it is easy to imagine the hen outdoors, finding interesting things to eat.

Yolk colour comes from pigments in the diet, and producers can influence it through feed. Maize, marigold-derived pigments and red-pepper ingredients can deepen the colour. Authorised pigment additives are also used. Turmeric has been studied as a feed supplement, with changes in yolk colour reported in some trials. [16, 17]

So the colour we associate with a garden hen can also appear in an egg from a bird kept indoors. An orange yolk tells us about pigment reaching the egg; the hen’s housing, freedom to forage and the egg’s wider nutrient composition need their own story.

What do the numbers stamped on eggs mean?

For commercially graded eggs, the first digit identifies the farming method. The letters identify the country and the remaining numbers identify the production site. [18]

Words such as “farm fresh” do not replace this information. Nor does an illustration of a farmhouse tell you how many hens share a building.

How much space do laying hens actually get?

The language becomes more revealing when we put numbers beside it.

These are selected requirements, rather than a full compliance checklist. Usable area has a technical definition and may include accessible levels in a multi-tier house. Certification can set additional conditions. Outdoor access is subject to permitted restrictions. [5, 14, 19, 20]

An A4 sheet measures about 624 cm². The 600 cm² usable allowance in an enriched cage is slightly smaller than a sheet of A4 paper per hen. The total allowance is somewhat larger. This is shared cage space, rather than a private compartment the size of a sheet of paper, but the comparison makes the density easier to picture.

For barn and free-range housing, imagine a square measuring one metre by one metre. Nine hens per square metre is the permitted density across usable area. It does not mean nine birds are permanently confined inside each marked square; it tells us how crowded the house may be overall.

The conventional barren battery cage was banned in 2012. Enriched cages added features such as nests, perches and a scratching area, but confinement remains. “Battery cages were banned” can therefore give shoppers an incomplete impression of what disappeared. [5, 21]

Does free-range mean hens spend all day outside?

Free-range offers an important opportunity: access to an outdoor environment. But a door and a field are only part of what makes that opportunity usable.

Trees, shrubs and shelters can make exposed ground more inviting. Exit design, flock size, weather and the condition of the land influence what birds actually do. A muddy strip outside a busy doorway and a varied, sheltered range offer different experiences.

British Lion free-range rules allow flocks of up to 16,000 hens, with division into colonies of up to 4,000 where flock size exceeds 6,000. That is a long way from the small garden flock many people picture when they read the label. [19]

Can free-range eggs come from hens kept indoors?

Yes. In England, a 2025 rule change removed the previous 16-week limit on retaining the free-range label during compulsory disease-control housing. Eggs can retain that designation throughout imposed mandatory housing measures. [22]

This exemption concerns disease-control restrictions. It is not general permission to keep hens indoors indefinitely by choice.

For shoppers, however, there is a meaningful distinction: the label can describe the farm’s production system while its hens currently have no outdoor access. Producers can help by explaining their current situation openly.

Organic eggs and pasture-raised eggs: what is the difference?

Organic is a regulated certification framework. It affects feeding and husbandry as well as access to land. Organic hens are kept at a lower indoor density, and their feed cannot contain GM ingredients. Some certifiers require more than the baseline. [14, 20]

It still does not tell you that every hen spends every day grazing an expanse of fresh grass. Hens forage rather than graze like cattle, vegetation varies, and restrictions can interrupt outdoor access.

“Pasture-raised” can describe a thoughtful system involving mobile housing, rotational land use and varied outdoor feeding opportunities. In England, though, it does not provide a separate numbered production category with one uniform set of egg-marketing requirements.

Ask about the substance behind it: how often housing moves, how vegetation recovers, how many hens share the land and what feed they receive. An American pasture-raised certification should not be assumed to apply to a British carton.

British Lion, RSPCA Assured and Red Tractor explained

An egg box can carry several logos at once. Each tells you about a different part of production, and understanding them helps you see what you are paying for.

British Lion includes salmonella vaccination, hygiene controls, testing and traceability. It operates across production systems, including cages. It cannot, by itself, tell you that a hen lived outdoors. [23]

RSPCA Assured certifies against RSPCA welfare standards and does not permit cages. It covers barn as well as free-range and organic systems. The logo therefore does not automatically mean pasture access. [24]

Organic certification imposes requirements on feed and husbandry. The certifier matters because standards can exceed the legal baseline.

Red Tractor is a separate assurance scheme covering agricultural sectors. Its chicken standards should not be confused with the British Lion table-egg scheme, or treated as a synonym for free-range. Check the particular product and claim. [25]

Certification gives us standards against which farms can be assessed. A logo cannot show us every bird’s condition every day. Meaningful scrutiny includes inspection findings, responses to breaches and actual outcomes such as injuries, feather damage and mortality.

We can value a requirement while still questioning whether it goes far enough.

The hen’s life before and after the egg box

The laying house is only one chapter.

Young female birds, called pullets, are reared before entering the laying flock. Early opportunities to exercise, perch and navigate matter when they later move into more complex housing. Breeding priorities shape egg output, size, laying persistence and physical resilience. [6, 21]

Producing eggs places substantial demands on a hen. Calcium supply matters, but a sound shell cannot serve as a full assessment of her skeleton. Keel-bone fractures, injurious pecking and feather damage are important welfare concerns. Cage-free systems allow more movement and behavioural choice, while house design and management still need to prevent collisions, falls and other injuries. [6]

Think, too, about the hours we rarely see: where a hen settles at night, the air she breathes in the house, and whether her litter is dry. Parasite control, shelter from uncomfortable temperatures and proper rest are part of caring for her. The English welfare code recommends sufficient uninterrupted darkness, approximately a third of the day. Her daily rhythm matters throughout the year. [5]

Commercial flocks are commonly replaced when production or egg quality no longer meets the business’s requirements. Many birds are slaughtered at around 18 months to two years, although flock cycles vary and some systems keep hens longer. Rehoming gives some birds another life; it does not account for every end-of-lay hen. [21]

Male chicks from laying breeds raise another question. They do not produce eggs and are not bred for the same growth as meat chickens. Their culling has been part of conventional egg production; alternatives include determining sex before hatch and dual-purpose breeding.

Why are supermarkets selling more white eggs?

Shell colour is largely inherited. Different breeds produce white, brown, blue, green and other shades.

Some retailers are moving towards white-egg breeds because of production characteristics. Sainsbury’s, for example, attributes the lower carbon footprint it reports for its white eggs principally to feed efficiency and a longer productive lifespan. That is the retailer’s account of its supply, rather than proof of every white hen’s welfare. [26]

The useful questions concern the breed and farming system: how long hens live, how robust they are, how they are housed and what their health records show. Shell colour alone cannot answer those questions.

Are large eggs bad for hens?

Egg size varies with age, genetics, feeding and health. Younger hens generally begin with smaller eggs; older birds tend to lay larger ones. Double yolks can also produce unusually large eggs.

Our own well-cared-for chickens can produce enormous eggs. Size alone cannot tell you how well a bird lives.

The specific welfare concern is encouraging inappropriate egg size, especially in young hens, which can increase problems such as prolapse. Mixed-weight boxes provide an option for shoppers who want to accommodate natural variation. [16]

UK grading is by weight: small is under 53 g; medium is 53 g to under 63 g; large is 63 g to under 73 g; very large is 73 g or more.

Why do Americans refrigerate eggs when British shops often do not?

American and British egg handling follow different systems.

USDA-graded shell eggs are washed and sanitised, and American rules require consumer shell eggs to be kept refrigerated. In England, washing or cleaning eggs for sale as Class A is prohibited, protecting the shell’s natural barriers. [27, 28]

British supermarket display at room temperature does not mean eggs should be left somewhere warm indefinitely. UK retail instructions say to refrigerate after purchase. Keep them in their carton, follow the date and avoid repeated temperature changes. [29]

Bringing the hen back into the picture

Keeping chickens has made it difficult for me to think of an egg as an anonymous ingredient.

I know the searching, scratching creature behind it. I know the excitement over a discovery in the garden, the mess on the doorstep and the small absence when one is no longer there.

Many households once had a closer relationship with at least some of their food. We cannot all keep hens, and buying eggs should not require a poultry-science qualification. But we can recover enough understanding to recognise what a label tells us and ask about what it leaves out.

Next time you pick up a box, imagine the hen’s day. The ground beneath her feet, the food she searches for, the air she breathes and the space she can move through. Think of the changing daylight, and somewhere comfortable to settle when it grows dark.

There is an extraordinary food inside that shell. There is a whole life behind it too.

Sources and further reading

These sources bring together farming standards, poultry husbandry and research into feed and egg composition. Assurance schemes describe their own requirements; the research notes identify the particular experiments behind the claims.

1. British Egg Industry Council: egg nutrition.

2. NIH: choline and its physiological roles.

3. University of Minnesota Extension: seasonal laying, moulting and winter feed needs.

4. University of Kentucky poultry extension: laying cycles, nutrition and light management.

5. English welfare code for laying hens and pullets.

6. EFSA: welfare of laying hens.

7. British Egg Industry Council: feed and other egg questions; University of Georgia: soya quality control.

8. Oliveira et al., 2010: dietary lipid sources and yolk fatty acids.

9. WWF: The Soy Story Revisited, 2025. Supply-chain assessment of soya sourcing, deforestation and habitat conversion.

10. Fresh and oxidised feed fats study, 2021.

11. Saitoh et al., 2001: isoflavone transfer into yolk.

12. Carlsvig et al., 2022: glyphosate feeding experiment.

13. Food Standards Agency: GM food labelling.

14. Soil Association: organic eggs.

15. Sunlight exposure and egg vitamin D study.

16. RSPCA Assured: shell colour, yolk colour and egg size.

17. Turmeric supplementation experiment; FSA: canthaxanthin feed authorisation.

18. APHA: egg marketing standards. Some passages on this page lag subsequent legislation; current housing provisions are sourced separately below.

19. British Egg Industry Council: free-range requirements.

20. Soil Association: current Great Britain organic standards.

21. RSPCA: laying hens and egg farming.

22. 2025 English free-range marketing amendment: explanatory memorandum.

23. British Lion Code of Practice.

24. RSPCA: egg labels and eggs used as ingredients.

25. Red Tractor: chicken standards.

26. Sainsbury’s: sourcing eggs and white-egg breeds.

27. USDA: commercial egg washing; US refrigeration rules.

28. APHA: egg quality standards, including washing.

29. Trading Standards guidance: retail labelling and storage.

30. Australian backyard chicken and soil-lead research.