When it comes to your local supermarket, the eggs are going to be kept in one of two places. If you are in the United States, Canada, Japan, or Australia, you are going to find them in the refrigerated section, typically where the milk and cheese are found. However, if you live anywhere else in the world such as Europe or Asia, you are going to find them out on a regular shelf. This cultural difference may seem weird at first, after all, eating the eggs both ways does not cause any ill effects. So, why do Americans refrigerate their eggs? It comes down to how salmonella, a bacteria, contaminates and infiltrates eggs.
What Is Salmonella and How Does It Contaminate Eggs?
Salmonella is a bacteria that causes a food-borne infection commonly known as Salmonellosis. It is accompanied by fevers, stomach cramping, nausea, diarrhea, and vomiting. The bacteria is spread by eating contaminated food that has had infected with the bacteria from the feces of a person or animal. It can also be ingested through infected water and spread from one person to another. The bacteria is commonly found on wild and domestic animals including poultry, cattle, rodents, wild birds, and domestic pets like cats and dogs. With eggs specifically, salmonella can enter into the egg one of two ways. First, the bacteria can internally infect the egg prior to the hen laying in, or second through the porous egg shell.
How The United States Deals With Salmonella Risk
Due to there being numerous outbreaks of salmonella poisoning in the United States from contaminated eggs, the United States Department of Agriculture mandated that eggs were to go through a rigorous washing and refrigeration process. All eggs must be washed in water with a minimum temperature of ninety degrees Fahrenheit, then be chemically sanitized with a solution like chlorine and then rinsed thoroughly and dried. Once the eggs have dried, they are sprayed with a mineral oil to help keep their outer shells protected from potential contamination. This process effectively deals with any external sources of salmonella that may have been on the external pores of the egg. For the internal risk, the United States mandated that eggs were to remain refrigerated, however, once you begin the refrigeration process that process cannot be interrupted as the egg will sweat, causing the facilitation of bacteria growth that could compromise the egg.
How The European Union and Asian Countries Deal With Salmonella Risk
The European Union actually prohibits the washing of eggs and instead advocates for the use of the egg’s natural protective coating. This coating is called the cuticle, which is placed onto the egg as a liquid when the egg is laid. When the egg is exposed to the air, it dries out immediately. The only downside to this process is that the chances of cross-contamination are higher if the eggs are bought and shipped with fecal matter on them. However, one can avoid any contamination by washing them prior to use. The upside is that this promotes good farm husbandry, saves a lot of money, and does not require farmers to put a huge amount of effort into the egg harvesting process. As for the internal protection against salmonella, the European Union requires all farmers to vaccinate their chickens against salmonella.
Overall, while both methods have their pros and cons, the one thing to keep in mind is that if you choose to not refrigerate your eggs, their shelf life will decrease considerably to about three weeks. If you choose to refrigerate, you can keep your eggs good for up to two months.
