The FDA estimates that salmonella-contaminated eggs cause 142,000 illnesses each year. The 2010 salmonella outbreak traced to two farms in Iowa that resulted in the recall of over 500 million eggs may have changed where you source your eggs from, but did you know that even organic, pastured eggs can be infected with salmonella? Here's a quick primer on salmonella and safe egg handling.
Salmonella, a type of bacteria, is transmitted to eggs through infected chickens, whose environment is easily contaminated by carriers like rodents, birds and flies. Once infected, a chicken shows no outward signs of illness, but some of her eggs may have a small amount of salmonella deposited in them. Though this amount is harmless, it can rapidly increase to dangerous levels if the eggs aren't cooled quickly and kept cool throughout their storage and shipment.
Eggs can also become infected from the outside in, picking up the bacteria from a contaminated environment or tainted equipment used in the cleaning and packing process.
Although there isn't much you can do about how eggs are handled before they arrive at the store, there are a few steps you can take to minimize your risk of salmonella infection.
• Be a careful buyer.
Buy eggs that are clean and free of cracks. The FDA recommends only buying eggs from refrigerated cases, but most eggs sold at markets by local farmers are kept at room temperature, and I would say part of being a careful buyer is knowing the conditions under which your eggs are farmed. The eggs I buy from a local farmer not only come from a small farm I know to be clean and well-maintained, they are also much fresher, which makes them preferable to buying refrigerated eggs at the supermarket which have traveled great distances from an unknown farm and processor. It's not a risk recommended by the government, but it's the choice I've made for myself. Regardless of where you buy your eggs, refrigerate them as soon as you get home, keeping them in their original carton in the coldest part of the fridge.
• Don't cross contaminate.
Before working with raw eggs, clean your work surface, utensils and hands thoroughly with soap and water. Do the same with any surfaces that come in contact with raw eggs during the cooking process.
• Cook eggs thoroughly or use pasteurized eggs.
To avoid salmonella infection, eggs should be cooked until both the whites and yolks are firm. Egg-containing dishes like casseroles should be cooked to at least 160°F. What to do if you like runny eggs or need a raw egg for a dish like Caesar salad? You can use pasteurized eggs, which have been heated to a temperature that kills the bacteria, a choice recommended by the FDA especially when cooking for the elderly, the very young, or anyone with a compromised immune system. If you cook non-pasteurized eggs just until the yolks are runny, they will not reach a high enough temperature to kill the bacteria, so you run the risk of infection. Whether or not this is an acceptable risk is your choice.
More About Eggs & Salmonella:
• Tips to Reduce Your Risk of Salmonella from Eggs at the Centers for Disease Control
• Eggs & Egg Safety at FoodSafety.gov
• Playing It Safe With Eggs at the U.S. Food and Drug Administration
• How Does Salmonella Get Into Eggs? at Discovery News
Related: How To Prevent, Cure, and Cope with a Foodborne Illness While Traveling
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Living in Europe, all the eggs I buy are kept at room temperature. I believe our eggs aren't washed the same way that eggs are in the US, and so are able to be kept safely out of the fridge.
"... but did you know that even organic, pastured eggs can be infected with salmonella?"
I don't quite get this line. This implies organic things are usually less prone to infection. Is that true?
I thought I read something on this very blog, maybe years ago, saying that only certain food products were better organic, or even saying that organic food has a higher chance of having other "things" living in and on them because they're organic.
This is perhaps a stupid question but is there a good way to pasteurize eggs at home? I suspect the oven would get too hot even at its lowest setting (about 200F)
I'd like to try out some homemade mayo sometime soon but I confess that I'm a little worried (though this is the same guy who last night licked his fingers while mixing homemade ice cream before it was heated to 175 ...
regarding the comment that even organic eggs can have salmonella is to dispel a false sense of security that people have about their food. they think if it's from a small farm ran by just a farmer and his family that all the food that is produced there is free of the negatives that commercially raised food has.
i'm assuming..
@GaryLikesToCook: Many people are under the mistaken belief that salmonella doesn't infect hens that are free range or pastured or otherwise differentiated from the average battery-cage hen, but that isn't true. In this case, I think some take "organic" on the label to mean a better environment for the chicken, which they may think is safer from salmonella. Unfortunately, neither is necessarily true. (Here's The Humane Society's guide to egg carton labels for anyone who is interested.)
@Battra92: Unfortunately, I have not heard of a method to safely pasteurize eggs at home.
A bit of googling suggests some methods for pasteurizing eggs. It seems like a water bath held at 140 degrees long enough for the yolk to heat through should do it. I'm not qualified to say whether that will be effective. Maintaing a water bath like that would be a lot easier with a sous vide/"water oven" rig of some kind... worth it if you're afraid of salmonella and really like runny yolks?
Yeah, I'm in the same boat as Battra92 on wanting to try homemade mayo but being a bit squeamish--I had salmonella poisoning as a teenager from undercooked scrambled eggs at camp, and it was NOT FUN. Although to this day I still enthusiastically eat raw cookie dough and cake batter with no qualms...but some things just are not worth giving up. : )
Regarding the "even organic, pastured..." comment, I was always under the impression (not sure why/from where) that the *crowding* of factory farm conditions were more conducive to salmonella contamination, while the openness of pasture-raised was lower risk. But never thought it had anything to do with organic, per se.
It's not that organic eggs don't have salmonella. It's that the chance is a little smaller, because the hens are not all close together lying in their own filth. If one of them is contaminated, it's harder to pass it on to another one. But the chance exists. And there's also another theory that says that people less concerned with the radical levels of higiene that western society imposes have stronger immune systems. They have been infected one time or another with salmonella, but it's just a stomach ache, and not fatal. However, people to neurotic with higiene suffer the whole effects of salmonella.
I've been consuming raw eggs for my entire life and never got salmonella. And I live in Brazil. And my toddler son eats homemade mayo. No problem. :)
I read somewhere that 1 in 10,000 eggs is infected with salmonella. I have eaten things with raw egg (dough, batter) throughout my life without getting sick, though I wouldn't risk it if I were chronically ill.
I saw somewhere where someone made Caesar dressing without egg (I think it was on Secrets of a Restaurant Chef) and she said it made little difference, interestingly, which is nice if you don't want to worry about raw egg or don't have any pasteurized eggs.
I, too, eat plenty of raw egg without fear of contracting salmonella (homemade mayo, caesar dressing, gin fizz, batters/doughs). It's such a small risk that I don't worry about it, but then again, I typically buy the most expensive eggs the grocery store offers. I don't buy into all the organic, free-range nonsense, but I'm also not about to buy a dozen eggs for only $0.99.
Edit to the above: *Gin Flip
I've also eaten raw eggs my entire life (tiramisu, chocolate mousse, mayo). I eat a raw egg yolk everyday as well w/o any ill effects. Granted, I buy fresh pastured eggs at the Farmers' Market straight from the farmer. If you have a compromised immune system for any reason I wouldn't recommend eating raw eggs, but if you're healthy and trust the source and freshness of your eggs, I wouldn't stress about it too much. Having said that, if I was having a dinner party and had made mayo or a dessert with raw eggs, I would be sure to let everyone know.
Salmonella can also come from chicken poop. When eggs are washed and then left to sit, any residual salmonella can enter the egg through the shell, which because it was washed has lost its protective barrier against contamination (just think - otherwise baby chicks would be subjected to a LOT of pathogens). So if you get farm-fresh eggs with some chicken poop still on them, just brush it off. Refrigerate the eggs and only wash them just before use. Also wash your hands between cracking eggs, especially if you are not going to cook them thoroughly. Avoiding contact of the whites to the outside of the eggs while cracking can also help.
I never use raw eggs, but I am a big fan of fried eggs over easy - gotta just love that runny yolk! So I just try to be careful, especially since most of my eggs are pre-washed from the grocery store.