Sainsbury's has announced it will stop selling brown eggs in favour of white ones, citing a 12.7% lower carbon footprint. The decision has led many Brits to question whether any nutritional difference exists between the two varieties, and whether the move is enough reason to take their shopping elsewhere.
Why Sainsbury's Is Switching to White Eggs
The supermarket chain has justified the switch by claiming white eggs carry a 12.7% lower carbon footprint than brown ones. This is because hens producing white eggs consume less feed while laying the same number of eggs, reducing the resources needed throughout the supply chain. Feed production is responsible for between 50-60% of the environmental impact associated with egg farming.
Britain consumes around 14.5 billion eggs every year, generating an estimated 4.35 million tonnes of carbon dioxide emissions. If the entire industry were to achieve the same 12.7% reduction Sainsbury's claims, annual emissions could decrease by more than 550,000 tonnes of CO2, according to The Independent — almost the same as taking nearly 300,000 cars off Britain's roads, reports the Express.
Does Eggshell Colour Affect Quality?
For much of the 20th century, white eggs were standard in the UK. During the 1970s, however, brown eggs became established as a middle-class staple and went on to dominate the market. Today, the vast majority of eggs sold are brown, and many believe the darker the shell and the deeper the orange of the yolk, the superior the quality. In reality, there is very little to distinguish between the two differently coloured eggs.
Influencer Sunna Van Kampen, known on TikTok as @tonichealth, has argued that the striking bright orange yolks are not an indicator of quality, but rather a consequence of the hens' diet. Sunna, who has amassed 8.5 million likes on the platform, said: "The reason why your yolks are so dark and orange... is because they feed [the hens] marigold and paprika." This was confirmed by a 2024 study published by the National Library of Medicine. "We found that paprika improved the color of the egg yolks and affected the hens' blood cholesterol levels in different ways," the study claims.
What Determines Eggshell and Yolk Colour?
The shade of a yolk is largely dictated by pigments known as carotenoids, which are found naturally in ingredients such as maize, marigold, peppers and carrots. The colour of an eggshell is determined by the breed of hen that laid it. As a general rule, white hens produce white eggs while brown hens produce brown eggs.
According to British Lion Eggs, there is no nutritional distinction between white and brown shelled eggs. The code stamped on the shell is a lot more significant. Organic eggs are marked with a 0, free-range eggs a 1, barn eggs a 2 and eggs from caged hens a 3 — although all major supermarkets have since stopped stocking caged hen eggs.
Environmental and Cost Benefits
Neither the shell nor the yolk colour provides any indication of the hen's health or whether the egg will produce a better omelette. What it does reveal is that stocking white eggs proves considerably more cost-effective for supermarket chains such as Sainsbury's — and potentially better for the environment as well.
