Sainsbury's Ditches Brown Eggs in Net Zero Push as 'Research' Challenges Long-Held Shopper Beliefs

Sainsbury's is phasing out brown eggs from its own-brand ranges and replacing them with white-shelled alternatives as part of its efforts to reduce carbon emissions across its supply chain.

The supermarket said the move is based on research showing that white eggs have a 12.7 per cent lower carbon footprint than brown eggs. According to Sainsbury's, the hens that lay white eggs are generally smaller and require less feed, reducing emissions linked to egg production.

The decision also challenges a long-held belief among some shoppers that brown eggs are healthier, more natural or of higher quality than white eggs. However, shell colour does not determine an egg's nutritional value, taste or freshness.

Why Sainsbury's Is Switching to White Eggs

Sainsbury's said the transition forms part of its wider environmental targets, which include reaching net zero across its own operations by 2035 and throughout its supply chain by 2050.

The retailer said white-egg-laying hens consume less feed, which reduces demand for the resources used in feed production. It also argued that some white-laying breeds are less prone to feather pecking, which could support animal welfare improvements within its supply chain.

A spokesperson for Sainsbury's said white eggs provide the same nutritional benefits and taste as brown eggs while generating lower emissions.

The supermarket has previously introduced other environmental measures, including vacuum-packed minced beef, as part of efforts to reduce waste and lower its environmental impact.

Why Brown Eggs Became More Popular

White eggs were once common on British supermarket shelves, but consumer preferences shifted during the 1970s as brown eggs became increasingly associated with traditional farming methods and perceived health benefits.

Many shoppers came to believe that brown eggs were more nutritious or came from higher-welfare farms. However, experts say shell colour is determined by the breed of hen and does not indicate nutritional value, freshness or quality. Professor Ian Dunn, an avian biologist at the Roslin Institute at the University of Edinburgh, has previously said that shell colour is linked to genetics rather than what is inside the egg.

Factors such as feed, age and welfare conditions have a greater influence on the characteristics of an egg than the colour of its shell.

While white eggs dominate markets such as the United States, brown eggs remain the preferred choice for many British consumers.

Some Farmers Question the Environmental Benefits

Not everyone in the poultry industry agrees with Sainsbury's assessment of the environmental advantages.

Some breeders argue that white-egg-laying hens have shorter productive lifespans than many brown-egg breeds, potentially offsetting some of the carbon savings associated with lower feed consumption. Others have questioned whether focusing on shell colour oversimplifies the environmental impact of egg production, which can also be influenced by housing systems, transport, energy use and feed sourcing.

The transition may also take time to implement. According to the British Free Range Egg Producers Association (BFREPA), white-egg-laying hens currently account for around 15 per cent of the UK's national flock after decades of consumer demand for brown eggs encouraged farmers to favour brown-laying breeds.

Despite the criticism, Sainsbury's said it will continue working with suppliers to transition its own-brand ranges to white eggs, arguing that the move offers environmental benefits without affecting quality, taste or nutrition for shoppers.