There's a global divide on the age-old question as to whether eggs should be stored in the fridge or kept at room temperature: Americans generally tend to store their eggs in the refrigerator to increase shelf life and to prevent bacterial contamination. On the other hand, overseas, the British are the least likely people in Europe to store their eggs in the fridge, the Daily Mail reports. The disparity between the way in which Americans and the British store their eggs may be attributed to several factors, such as different marketing regulations from each country. To crack the egg age-old debate, the Daily Mail commissioned a scientific study to reveal which side is correct — “chill eggers” or “warm eggers.”

Why Americans Refrigerate Their Eggs

For Americans, storing eggs in the fridge isn't simply a matter of taste — it's done to prevent the spread of Salmonella. According to the U.S. Food and Drug Administration (FDA), there are approximately 142,000 illnesses every year that are caused by consuming eggs contaminated with Salmonella. In the U.S., hens are not required to be vaccinated against Salmonella, with only one-third of farmers choosing to immunize their flocks.  

Because of these immunization policies and practicies, it is imperative to keep eggs refrigerated.To minimize the risk of contamination and to extend shelf life, eggs should be stored in the case or carton in a refirgerator. If done so, they should last up to four to five weeks without a significant loss of quality, according to the American Egg Board.

Across the pond, on the other hand, British laws require that all egg hens be vaccinated for Salmonella. Since the UK eggs scare in 1988, the Department of Health has taken precautionary measures to prevent a Salmonella outbreak. The Salmonella National Control Programme (NCP) prevents egg operators and producers from marketing eggs infected with the bacteria or that have an “unknown health status” (in other words, not tested, according to the NCP standards). The same standards are in place in many European contries.

Nevertheless, Britons remain divided on whether to keep their eggs on the counter or store them in the fridge

Chill Eggers on the British Isle

 Chill eggers strongly believe storing eggs at cooler temperatures will prevent Salmonella from multiplying. Chill eggers are also supported by Dr. Rosamund Baird and Dr. Janet Corry, two experts at Bristol University’s School of Veterinary Science who say that storing a contaminated egg at room temperature will only allow the bacteria to multiply.

Baird and Corry are aware that there are very few U.K.-produced eggs that contain Salmonella but their concern is rooted in the belief that “imported eggs are much more often positive for Salmonella.”

British Warm Eggers

Warm eggers in the UK are dumbfounded by the practice of storing eggs in the fridge. These advocates suggest that refrigerating eggs is useless in terms of safety and ruins their flavor, causing baking disasters, says the Daily Mail.

“A fresh, free-range egg should last beautifully at room temperature for at least a week,” said Tim Hayward, presenter of the Food Programme on BBC Radio 4 and restaurant columnist for the Financial Times. “The racks in the fridge door are the worst place to store eggs. The constant shaking thins the whites and the flavours of other foods can penetrate the shell."

Warm eggers stand their ground on the basis that supermarkets in continental Europe store their eggs at room temperature and not the fridge. In Europe, eggs are often sitting on an unrefrigerated shelf near the baking supplies. Eggs “should in general not be refrigerated before sale to the final consumer,” according to European Union (EU) law, Forbes reports. “Cold eggs left out at room temperature may become covered in condensation facilitating the growth of bacteria on the shell and probably their ingression into the egg,” reads the EU regulations.

The Resolution: Are Warm Eggs Safe?

To resolve the egg storage debate, the Daily Mail went to the West Yorkshire-based FoodTest Laboratories to compare Lion-branded British eggs bought from Tesco that were stored in the fridge to those that were kept at room temperature. FoodTest Laboratories provides government-approved laboratory analysis for the U.K. food and drink industry to observe the safety, quality, and legality of products.

One egg batch was kept at room temperature, generally between 68°F and 77°F, and the other was kept at typical fridge temperature at approximately 43°F. These samples were continuously tested for bacteria such as E. coli, Salmonella, and Listeria.

The results of the study showed that both batches of eggs were equally bacteria-free from the initial start of the study all the way to the end of the study — a span of two weeks. “There is no advantage in keeping the eggs refrigerated as opposed to storing them at ambient room temperature,” said Jay Tolley, the operations and quality manager at FoodTest.

The bottom line: because of the differences in hen vaccination policies,  Americans are advised to store their eggs in the fridge, but Britons can rest assured that whichever storage method they choose is completely safe.