Psst... We're working on the next generation of Chowhound! View >
HOME > Chowhound > General Topics >
Aug 15, 2014 09:30 AM

Mayonnaise safety: A question about salmonella on the shell of the egg (from a skeptic)

I was recently looking at a recipe for "Japanese" mayo (which, incidentally, seems pretty much like "European" mayo to me), and came across a curious warning in a footnote that I should wash the eggs with water before cracking the eggs because they could be covered with salmonella. Would water be effective? Wouldn't something stronger be needed?

Now, I have read on these boards that the outside of eggs from commercial providers are treated with something (soap? alcohol?) to kill off or wash off any bacteria or viruses. Is this true or not?

I have also read that the "dangerous" salmonella which accompanies an egg is on the INSIDE of the egg and arrived there through the chicken's internal egg-making organs, as the egg was being created, and is not found on the outside of the egg. Is this true or not?

I have also read that the FDA, or other authoritative sources, estimates that the number of salmonella infected eggs is one in 10,000/20,000/30,000/40,000, depending on where you get your information.

So, are these correct statistics? Can everybody stop worrying about eggs "crawling with unclean death"? This skeptic would like to know.

  1. Click to Upload a photo (10 MB limit)
  1. I don't know about the accuracy of the numbers, but in the US, eggs are washed and sanitized. There should not be any risk of bacteria on the surace of eggs as long as they are kept dry. But salmonella can be present inside the egg. That is why it is best to refrigerate eggs in the US.

    It is possible to get salmonella poisoning from an American egg, but I don't worry about it, even though I eat a lot of eggs with runny yolks. Salmonella outbreaks are rare. When they occur the source will be identified and the eggs will be recalled. Chances are it will be somebody else who gets sick.

    1 Reply
    1. re: GH1618

      If you've ever noticed though, recalls on perishable items (eggs, chicken, meat) often occur long after the expiration/best by date of the item in which case, most people who had purchased it probably have already consumed it.

      Last year they recalled millions of pounds of chicken breasts in late summer and they all had a use-by date of March something. I understand still releasing the information in case people had frozen the breasts, but I'd venture to guess most of the people who'd bought it had already cooked and consumed it (and possibly gotten sick).

    2. You can pasteurize your eggs at home prior to making mayo if you're worried about it. One of my neighbors had to take such measures when she was going through cancer treatment, which decimates your immune system. You can Google for info.

      5 Replies
      1. re: weezieduzzit

        Can't you just buy pasteurized eggs, or is it only the ones in cartons that come that way?

        I have also read those 1/30,000 statistics. Who knows if they're true.

        1. re: nothingswrong

          I just bought a carton of 'pasteurised' eggs at Publix to make mayo with... I know regular eggs are probably perfectly safe but I don't like taking chances.

          1. re: Kajikit

            Okay, I thought I'd seen them before.

            I think if anyone has any doubts, why not just get the pasteurized to be safe? I can't imagine they cost that much more, if at all, and then it's just one less thing to worry about.

        2. re: weezieduzzit

          Actually, I am not worried about it. I was being a bit sarcastic about the salmonella. The "crawling with unclean death" quotation is from a poem in science fiction writer Robert Heinlein's novel, "The Green Hills of Earth":

          "We rot in the moulds of Venus,
          We retch at her tainted breath.
          Foul are her flooded jungles,
          Crawling with unclean death."

          I meant to suggest that our concern about salmonella in eggs is a bit overwrought, in my opinion. Still, the questions I asked are questions to which I would like to get the answers.

          1. re: gfr1111

            Salmonella poisoning is nothing to joke about. I don't mean that people should be hysterical, but it is reasonable to be concerned and to take proper precautions.


        3. Some of your concerns may be addressed by the American Egg Board at:

          Our family owns a restaurant with an extensive breakfast menu; we sell 15-20 cases of eggs each week. We are not concerned about the outside of the shells. Salmonella occurs in undercooked eggs and is destroyed by thorough cooking. You are far more likely to contract salmonella by mishandling raw chicken.

          1. I have chickens, don't wash the egg shells (unless dirty) and make mayo weekly, prefer runny yolks, etc.

            The "other side" of the salmonella issue is that not everyone exposed to salmonella (or other hostile bacteria) gets sick. Most people are exposed quite a bit to small amounts of bad bugs (including stains of salmonella) with no ill effects. Larger amounts can get the better of anyone. Children, people with unhealthy guts, chronic disease, immune system problems, and people that take antacids have a much bigger chance of getting sick from exposure to all kinds of unfriendly bacteria.

            I keep my microbiome in good shape and have less to worry about (in general) so I don't worry about a 1 in 20,000 risk of being exposed to salmonella from an egg. So long as I don't take an antacid, eat a medium rare burger while swallowing it with a raw egg in my milkshake and playing with my pet turtle.... I should be fine :)

            8 Replies
            1. re: sedimental

              Ugh, turtles. I know a few people who have gotten (bad) salmonella poisoning from a pet turtle. One told me right after he got it, his dad took over turtle babysitting duties and then HE got it too. Dirty little buggers!

              Just wanted to agree with the rest of what you said though. IIRC we are okay eating xx/100 "particles" of salmonella in our food; typically our bodies will fight it off just fine and we wouldn't even know we were exposed. Then again, there's really no way of knowing how much salmonella we're consuming, and where our "tolerance" lies.

              That threshold would be much lower for the more sensitive groups you mentioned--weakened immune systems, and also the elderly, pregnant women, and children. I personally would be much more careful when serving "dangerous" foods to these groups.

              1. re: nothingswrong

                There is fascinating research coming out about gut health (good bugs and gut Ph).

                I am doing the American gut-human food project and learning a lot. I love it. Well worth the hundred bucks to start.

                1. re: sedimental

                  That sounds interesting. Never heard of it.

                  I agree about the research. With my own (serious) digestive issues, I've done some investigating myself and--while I don't want to get shut down for getting too off-topic here--I find your comments about prescription antacids to be spot on. Despite having really bad GERD since I was a wee lass, I outright refuse to take them now. I can see (and feel) that they have done real damage. Not to mention the addictive factor... the more you use them, the more you "need" them. It's insane.

                  I find the longer I've been off antacids, the easier it is to control my reflux without medication. The first few weeks off were really rough though.

                  1. re: nothingswrong

                    I think anyone interested in topics like this (food risks, good bacteria vs bad bacteria, gut health, prevention, nutrition) should check out the American gut:


                    If not to join and learn about all this, but to learn about their own personal bugs and how to encourage them! Fascinating stuff for a science/food geek :)

                    1. re: sedimental

                      I've been avidly following the NPR coverage of the human gut biome, and this really seems to be a new frontier of wellness that we've never considered before.

                      I don't think it's a magic cure-all for everything that ails us as a species, but I think it's of major importance and one we should all be paying attention to.

                      Thanks for the link!

                      1. re: sedimental

                        So have you sent in your sample(s)? I'm curious how to translate that data into your lifestyle--how do you figure out what kind of diet or supplements (probiotics for instance) you need? Do they provide you with recommendations for diet, or do you have to research that yourself?

                        1. re: nothingswrong

                          I don't want to get way off topic here but yes about the samples.

                          Yes you have to research it yourself ( but it is not hard as it is such a hot topic). Search the net for key words specifically related to gut health: resistant starch, feeding your microbiome, prebiotics, soil based probiotics, lacto fermented foods. Scholarly articles, theories, N1 experiments and blog/forums, research reports.... as well as weirdo's abound.

                          Once you get your report on your "own bugs", it is easy to see who took up residence in you..who you most likely want out...and who you want to encourage to stay and live with you to fight the good fight :)

                          1. re: sedimental

                            Great, thanks for the info. I admit I'm intrigued! Next time I have $100 burning a hole in my pocket, I will send off for the test kit.

              2. it's also helpful to look at the history of the issue - because a lot information continues to float around, but the conditions have changed making the 'old tales' more or less accurate.

                keep in mind, all this only applies to eggs sold with the USDA grade seal - and all the 'safety' bits in the regulations only apply to organization that observe 'the law' - there are companies/organization that intentionally do not observe 'the law' because it impacts the owner's profit....

                there's little question that coop dirt - or what passes for a coop dirt in factory farming - can contain salmonella and yes it gets on the outside of the eggs.

                enter the FDA / USDA with 'approved' washing/sanitizing/re-sealing procedures. despite that, there was an on-going fear that any salmonella on the exterior to penetrate a damaged / cracked egg. eggs are a really most excellent growth medium for bacteria, etc. - 'intentionally contaminated' eggs are used to grow bad stuff for vaccines..... but that's another story.

                so came the 'never use a cracked egg' thing, along with the refrigerate eggs thing. refrigeration slows down the bacterial growth. as someone noted, we eat a lot of 'germs' on a daily basis. but when you eat too many they overwhelm the immune system and you get sick. add the usual young/elderly/compromised statements.

                then it became discovered that a hen can lay an internally salmonella contaminated egg. and, just to add to the fun, that same hen can lay a contaminated egg today, and a non-contaminated egg tomorrow. bottom line: "culling" the herd isn't an option.
                so after that one has to cook any and all egg products to dry-as-dust (salmonella is killed at 131'F) "just to be sure"

                then entered the pasteurized in the shell thing. which I've read is really an iffy thing to succeed at with home kitchen resources - so do check a reliable source if you opt to go that route. 'reliable' does not include anything with 'health' or 'diet' or 'magic pixie dust' or 'mercola' or such in the url. there is a lot of bad information available.

                so what else has changed?

                well, technology has advanced a bit. especially in 'inspection' capabilities. computer vision systems don't miss many cracked egg anymore. which is wonderful, but eggs can be damaged after leaving the packing line.....

                the washing/sanitizing/re-sealing procedures are better / more effective / more consistent.

                enter the latest FDA/USDA regs requiring shell eggs be refrigerated with 24 hours of being laid, and kept under refrigeration until they go into your frying pan.

                the latest regs were fought tooth and nail by the industry because refrigeration ain't cheap.

                but WAIT! there's MORE!
                as you may know, not many European countries / kitchens refrigerated eggs. so why is they not all dead from salmonella?
                ahhhh, there is a proven salmonella vaccine for chickens. been around for decades. in the last century when I initially looked, it cost $0.05 per hen. I understand the current cost is about $0.15 per hen. the industry refuses to go that route, and the FDA/USDA does not require it because.....costs money.

                an egg farm with half a million hens - 500,000*$0.15 = $75,000. not an insignificant number. a 'Beamer or so...

                I forget which, but lately one of the low countries (Belgium/Netherlands?) registered like four cases of salmonella poisoning in an entire year - and everyone of those was traced to a tourist on vacation somewhere not observing domestic practices....

                so let's do some math.
                a hen lays on average one egg a day - you get six eggs a week.
                the economical life cycle is two years production before the egg count declines to 'below cost'
                52 weeks per year, 6 eggs per week, two years = 624 eggs per hen per productive life.
                $0.15 vaccination cost divided by 624 eggs = $0.00024 per egg, or $0.002885 per dozen.
                wonder how much the refrigerated warehouses and trucks cost......
                one of those cases of 'be careful what you wish for' - the industry defeated required vaccinations; and got hit major big time with refrigeration costs.

                4 Replies
                1. re: PSRaT

                  Thanks! That was a very interesting read.

                  1. re: PSRaT

                    I ditto what VTB said. Thanks! It is always fascinating to listen to someone who knows what they are talking about. You obviously do.

                    1. re: gfr1111

                      thanks for the kind words.

                      egg stuff - all kinds - is such a recurring topic.

                      and there is a lot of misinformation floating about. not that the regulators make things easy.... check this:

                      We are adopting as a final rule, without change, an interim final rule that amended the voluntary shell egg grading program regulations by adding a definition of the term “ambient temperature,”

                      ....adopting a final rule of an interim final rule.... yeah, okay. got it!