To wash or not to wash…

Why American Eggs Would Be Illegal In A British Supermarket, And Vice Versa (material published by

Believe it or not, United States Department of Agriculture (USDA) graded eggs would be illegal if sold in the UK, or indeed anywhere in the European Union (EU). It’s all to do with the fact that commercial American eggs are federally required to be washed and sanitized before they reach the consumer. EU egg marketing laws, on the other hand, state that Class A eggs – those found on supermarkets shelves, must not be washed, or cleaned in any way.

“In Europe, the understanding is that this mandate actually encourages good husbandry on farms. It’s in the farmers’ best interests then to produce to cleanest eggs possible, as no one is going to buy their eggs if they’re dirty, ” explained Mark Williams, Chief Executive, British Egg Industry Council in a phone interview.

According to the USDA, despite how conscientious and thorough modern day farm-management practices might be, there will still be a small percentage of “dirty eggs” produced. Dirt almost always equates to chicken manure and, if the eggs are produced in a free-range system, other raw agricultural commodities that hens might pick up from roaming freely.

Any feces on the exterior of an egg shell poses a food safety threat from potential cross-contamination if, say, a consumer cracks open an egg then proceeds to prepare a salad with those same bacteria-riddled hands. Since egg shells are porous, there’s also the possibility of micro-organisms migrating inside the egg under certain conditions.

A Thorough Clean

The USDA requires producers to wash eggs with warm water at least 20°F warmer than the internal temperature of the eggs and at a minimum of 90°F. A detergent that won’t impart any foreign odours to the eggs must also be used. After washing, the eggs must be rinsed with a warm water spray containing a chemical sanitizer to remove any remaining bacteria.  They are then dried to remove excess moisture.

This last step is crucial because bacteria cannot penetrate a thoroughly dry egg shell. Add a thin layer of moisture, however, and not only is there a medium that promotes bacterial growth, but the water also provides an excellent vehicle for pathogens such as salmonella and other critters to pass through via the tens of thousands of pores on the surface of the egg shell.

It’s in part because of the above risk that the EU has ruled out egg washing, asserting that careless washing procedures can lead to more damage than good. A critical scenario would be if a facility wasn’t prudent in regularly changing the washing water and eggs were left to sit in a dirty bath – ideal conditions for bacteria to infiltrate through to the inside of the eggs. Worst still, would be if cold water was used.  A washing solution colder than the egg could cause the contents of the egg to contract, so drawing polluted water in through the shell (hence the USDA’s thorough guidelines for water temperature).

Natural Protection

Then there’s the matter of the cuticle. Just as a hen is about to lay an egg, she applies a liquid coating around it that naturally protects against contamination. It also helps prevent moisture and carbon dioxide loss that in turn leads to an overall degradation in the quality of the egg. This layer, called the cuticle or bloom, is still wet when the egg emerges, but quickly dries after a few minutes.

According to the text of the EU egg marketing regulations this cuticle provides “an effective barrier to bacterial ingress with an array of antimicrobial properties.” It goes on to add that washing is prohibited because it could damage the cuticle making eggs even more vulnerable to contamination from pathogens and other micro organisms rather than providing an additional safety net.

Even the USDA’s official Egg-Grading Manual concedes that research has shown that washing removes most of the cuticle. To compensate for this, egg producers in the US commonly used to spray eggs with a thin layer of odorless, colorless mineral oil. Today, this practice is only used on about 10 percent of commercial eggs in the US. It was much more prevalent ten to twenty years ago because eggs were held in cold storage for much longer then before distribution – often up to a year after lay, explained Howard Magwire, Vice President of Government Relations, United Egg Producers, in a phone interview.  Consequently eggs needed to be well preserved and effectively guarded against contamination.

Such long storage periods were necessary because egg production was not consistent with seasonal variations. In the height of winter, cold temperatures slowed the rate of lay as hens sought to preserve their energy. In summer, they grew lethargic in the heat and again produced fewer eggs. Today, with sophisticated controls in place, production is consistent year round, and most Grade A eggs find themselves in consumers’ homes within weeks, if not days, of lay.

To Fridge of Not to Fridge?

Another important distinction between European eggs and American eggs is how they are stored, and this ultimately leads back to the question of egg-washing.

Go to buy eggs in Britain, France or Italy and you’ll find them sitting on an unrefrigerated shelf, often near the baking supplies in an aisle in the middle of the store. Head to an American supermarket however, and eggs are always held in refrigerated units, like milk and cheese and other dairy products.

EU law actually stipulates that eggs “ should in general not be refrigerated before sale to the final consumer.” The regulations explain how “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.”  Hence if a consumer picked up a carton of chilled eggs then transported them home in the car, the change in temperature would cause the eggs to sweat.

With precisely this scenario in mind, EU regulators considered it more judicious to maintain eggs in an ambient environment that resembles a “cool” room temperature from lay to shelf. In the UK, guidance set out by the Chartered Institution of Building Services Engineers recommends supermarkets maintain a temperature of between 66.2°F to 69.8°F in the winter and between 69.8°F and 73.4°F in the summer. Room temperature is generally considered to be between 68°F to 77°F.

The USDA is just as concerned about keeping processed eggs that move from a packing facility to a store shelf to the domestic fridge at a consistent temperature. However, on this side of the waters, that consistent temperature across the board should be 45°F or lower. As a point of contrast, in Britain, the Lion Quality Code of Practice  – an egg quality assurance scheme established in 1998, recommends that consumers keep their eggs below 68°F.

source:Forbes –