You know those human being who are telling you not to pack a tuna sandwich for the hike? Well, they're the ones who can take a hike, because mayo may actually be keeping us safe.

You are watching: How long can you leave mayonnaise out


*

*

Of every the anxieties surrounding taking work-related to lunch—and there space plenty, native what to lug said having lunch in, to making sure claimed lunch isn't stolen—perhaps no one is together nagging together the anxiety around mayonnaise.


*

In short, world seem persuaded that, if left at room temperature for also a short duration of time, the mayonnaise on their sandwich will certainly sprout all sorts of bacterial growths—growths the will cause illness, gaue won ruin, and also all kinds of other tragedies.


A seminal examine from 2000 took a look in ~ the fragility that mayonnaise and collection the record straight: "Salmonella, E. Coli O157:H7, E. Coli, L. Monocytogenes, Staphylococcus aureus, and also Yersinia enterocolitica die as soon as inoculated into mayonnaise and also dressings."


To put it simply as plainly, yet in layman's terms, store-bought mayonnaise has enough mountain (from vinegar or lemon juice) come not only kill food-borne pathogens, but additionally to protect against them indigenous forming.

What this way is the the angst around an egg salad sandwich—that is, the fear of letting the sandwich sit the end for an hour or two at room temperature since the mayo might spoil—is in reality backwards. If anything, the mayonnaise is preventing microbial growth. The egg (and turkey, and also sliced ham) would certainly be an ext dangerous without it.

Karen, the government's cartoon food safety skilled (yes, you review that correctly), concurs through the results of the study. Civilization often finger mayonnaise together the culprit for food-borne illness, yet according to Karen, "usually it's the meat, poultry, fish or egg in a sandwich kept out that the frozen fridge for much more than two hours that is the tool for bacteria to grow." (For a cartoon, Karen is really quite informed about these things.)

Some essential notes: This is just true v commercially-made, store-bought mayonnaise. Homemade mayonnaise, which supplies raw eggs, is a various matter altogether, and should be preserved cold. And because other materials of a sandwich room susceptible to spoilage, her lunch should most likely not sit the end at room temp—and certainly not in the sun (on, say, the beach)—for hours and hours on end.

See more: What Grade Is A 77 Percent, Is A 77 Percent Passing In College

But as soon as it comes to your commute, or leave a sandwich top top your workdesk for one hour or two, you have the right to relax. Emphasis on other lunch anxieties instead, like who stole your dessert from the fridge.