The Spots And Bumps On Your Eggshells Explained

Eggs and breakfast: It's an almost perfect combination. Certainly, Americans think so, since according to Mental Floss, each American ate an average of nearly 300 of them in 2019. But, of course, there are a few things everyone should know about egg safety and preparation in order to avoid bacteria like salmonella. Luckily, bumps and spots on your eggshells aren't something to worry about. In fact, both are rather common anomalies, and in both cases the eggs are still safe to eat.

What's interesting is what causes these anomalies in the first place. Brown spots occur on brown eggs (eggshell color depends on the breed of hen) when the egg spins too slowly as it passes through the oviduct of the hen. It's so common that these eggs even have their own nickname: "speckled" eggs (via Reader's Digest). Small bumps on eggs, meanwhile, are a textural anomaly that occurs in eggs of both colors, typically happening when the shell is being formed in the oviduct, as HowStuffWorks explains.

Since we've mentioned the oviduct twice, we might as well give you the short course on the hen reproductive system. First of all, per The Spruce Eats, most eggs sold in grocery stores are unfertilized, meaning no rooster was present. Egg yolks are produced in the ovary, then pass through the oviduct, a tube-like organ, and it is here the shell forms around the yolk through a process called calcification (eggshells are almost entirely made of calcium carbonate), and as said, when the spots and bumps on an egg can manifest.

So, you now know how eggs are laid, and also that the bumps and spots found on some eggs are nothing to worry about ... but how do you know it's safe to eat them? Well, according to the Centers for Disease Control and Prevention, only about 1 egg in 20,000 is found to be contaminated with salmonella, a bacteria that can cause illness.

But salmonella poisoning overall (including in poultry and other foods) causes 26,500 hospitalizations in the U.S. each year, and over 400 deaths. So always exercise caution when it comes to eggs. Buy refrigerated eggs and, as the Egg Safety Center advises, keep them refrigerated, as this not only helps to stave off bacteria growth but also preserves egg quality.

Southern Living, meanwhile, recommends using your eyes and sense of smell to test eggs, even those that haven't passed their expiration date — and most of us already practice doing so (e.g., why we wondered about those spots and tiny bumps to begin with). The magazine's most ingenious recommendation, however, is seeing if the egg floats in water. It is only older eggs that float, and although this in itself doesn't necessarily mean the eggs are bad, if you crack them and there is an off smell, they should definitely be thrown out.

Other safety to-dos in regards to eggs are common sense, per the CDC, including avoiding cracked and/or dirty eggs, making sure you wash your hands and utensils thoroughly, and that you are cooking your eggs properly.