Not long ago, I made a marble pound cake. Marble pound cake requires making a vanilla batter, adding chocolate to half of it, and then swirling the batters together in a pan. This meant that once my loaf pan was in the oven, I had two bowls and two spoons coated in sweet, egg-y batter. I licked them all clean. Please don’t be alarmed by my lack of manners: I was by myself at the time.
But, to be honest, I probably would have licked the bowl even if other people had been around. I always lick the bowl. When I was visiting family for Christmas a couple of months ago, I consumed cookie dough, fruitcake batter, and homemade eggnog. Every time I have made a type of cake or cookie for the recipe column I write for Slate, I’ve unfailingly consumed some of the uncooked mixture. Heck, every time I’ve made a type of cake or cookie just for fun, I’ve unfailingly consumed some of the uncooked mixture. And I have never in my 27 years gotten salmonella poisoning.
A quick back-of-the-envelope calculation: I estimate that I’ve baked cookies, cake, or brownies once a month, on average, since I started baking by myself around the age of 12 and that I have tasted the dough or batter every time. Let’s say that each of those batches of cookies, cake, or brownies has contained two eggs—a conservative estimate. This means that I have ingested the innards of—at the very least—360 uncooked eggs in my life. And this isn’t even counting the many times I licked brownie batter from my fingers as a small child, in direct defiance of my elders’ continual warnings: Don’t eat that, you’ll get salmonella.
Why have those prophecies turned out to be false? Is salmonella not as common as my parents, aunts, and teachers thought when they drilled caution into my head when I was in elementary school in the 1990s? Have I just been lucky not to encounter any salmonella-infected eggs in my career as a spoon-licker? Or have I been blessed with an exceptionally robust microbiome, rich with “good” bacteria that will overpower malicious invaders immediately, enabling me to eat all the raw eggs in the world without getting sick?
It’s probably mostly the first: Salmonella in eggs has always been rare, and it’s gotten even rarer since I was a kid.
Salmonella Enteritidis is the subtype of salmonella that’s most commonly responsible for salmonellosis, otherwise known as salmonella poisoning. Unfortunately, SE doesn’t produce any visible symptoms in egg-laying hens, which means that it can pass through henhouses undetected until consumers start complaining of diarrhea and vomiting, which are sometimes so severe that they lead to hospitalization. This is what happened in the mid- to late 1980s, when egg-associated salmonella outbreaks in the northeastern United States killed dozens of people and sickened hundreds of others. Following these outbreaks, egg producers started following protocols to prevent salmonella transmission among their hens. Pennsylvania, in particular, was at the vanguard of the salmonella prevention movement: The Pennsylvania Egg Quality Assurance Program has required participating farms to test incoming pullets (immature hens) for salmonella, prevent hens from coming into contact with other animals (like rats) that might carry SE, and keep eggs refrigerated at all times to prevent any bacteria from reproducing, among other measures.