Hello again After my recent video about how to store eggs for eating during the winter lots of people asked me whether I washed the eggs before putting them in the fridge. No, I didn’t and that’s not because I’m lazy It’s because the best way to make sure an egg is clean and stays clean and fresh is not to wash it. And if that sounds odd, let me explain. Eggs come naturally with a protective layer called a cuticle on the outside of the shell. A couple of years ago some high-powered research by scientists at the universities of Edinburgh and Glasgow finally answered some of the questions about this cuticle, like when and where it comes from – the answer is the cuticle is made in the shell gland. And whether the cuticle has any relationship to the shell pigment – No, it doesn’t. Eggshell has lots of tiny pores in it, which allow oxygen to pass through the shell. This is essential if the egg is to be nourishment for a developing chick inside. But those pores can let in not only oxygen but also bacteria and inside the protein-rich egg, bacteria would grow and multiply quickly, rotting the egg and killing any baby chick inside. Not what the mother bird or hen had in mind at all. So the outside of the egg has a tiny invisible shield of protection called the cuticle. The cuticle allows oxygen to pass through the pores of the shell but keeps bacteria out. Water birds like ducks tend to make their nests in damp mucky places, and they coat their eggs with a really thick strong cuticle to provide the egg with maximum protection. Budgies who come from hot dry climates where bacteria don’t grow very well anyway don’t bother with a cuticle on their egg at all. And hens are somewhere in between. The cuticle on hens eggs is a light invisible protective coating. The cuticle is still liquid when the egg is first laid but within a few minutes it dries to an invisible protective layer. So if your hen naturally lays her egg with an invisible protective shield why would you want to wash it off and expose the egg to any bacteria in the environment? Well, did you know that most of the commercially sold eggs in the United States are washed and that natural protective layer is replaced by an artificial coating? It’s a long story as to why that is. Let me explain. It’s all about a nasty bacteria called Salmonella. Chickens can be infected with salmonella and if eggs come into contact with their bacteria-laden poop, the bacteria eventually bypass the cuticle and get into the egg. In the big commercial egg factories with thousands of chickens, it’s not uncommon for this to happen. So the United States Department of Agriculture made a rule that all eggs sold commercially must be washed. Now, this is no simple swish around in the soapy water. The water must be 90 degrees Fahrenheit – that’s 32 degrees Celsius. And the water must be at least 20 degrees Fahrenheit warmer than the internal temperature of the egg being washed. If this temperature differential is not maintained bacteria from outside the egg could be sucked straight inside the egg instead of being washed off. The wash liquid contains some detergent And it’s essential that the egg is quickly removed from the wash liquid, then rinsed in the warm water spray containing a chemical sanitizer such as chlorine. Then dried within a very few minutes so that dirty wash liquid itself doesn’t contaminate the egg. And then the egg may be coated with some kind of artificial coating such as mineral oil because without its cuticle the egg loses its freshness faster. And from then on the eggs must be kept perfectly refrigerated right up until you eat them. As I said all of this is about protecting the American egg consumer from the risks of salmonella food poisoning but in spite of all that there are still about a hundred and forty thousand cases of salmonella food poisoning in the United States each year. In contrast to the United States rule, in Europe. It’s actually illegal to wash eggs that will be sold to the public. That means the cuticle of the egg stays intact and it also encourages farmers to make sure that their hen houses and therefore the eggs are kept nice and clean because nobody wants to buy a dirty looking egg. That’s good for the chickens, and it’s good for us. And does it work? Does leaving the cuticle on the egg actually protect the consumer from the risks of food poisoning? Well, it seems like it does. Even though eggs in European supermarkets are not refrigerated there are very few cases of salmonella food poisoning related to eggs in Europe. And in the last 20 years eggs have been considered very safe indeed – even safe enough to eat raw. Have a look at my video about the risks or not of eating raw eggs. It’s not really a fair comparison between European and American rates of egg related salmonella food poisoning because in Europe it’s a requirement that chicken farmers vaccinate their hens against Salmonella and that’s not the case in America. However in America more and more chicken farmers are deciding voluntarily to vaccinate their chickens, and so the risk of getting Salmonella from American commercially-laid eggs are getting lower all the time. So do I wash the eggs from my chickens? No, I don’t. If I got the occasional egg that was particularly dirty I might wipe it clean and I would certainly use that egg promptly before any bacteria had a chance to multiply, but I would never wash away that protective cuticle layer, not only because it’s tricky to do safely and effectively, but also because it seems to be more effective to simply leave that cuticle layer intact, with its natural invisible layer of protection. And I think you should too. Thanks for watching.