To refrigerate or not? If you spend a great deal of time in the kitchen, you've probably asked this about several common kitchen items, leftovers, and even eggs. When it comes to egg storage, it all depends on your geographic location. Different countries handle food storage differently — so who should refrigerate their eggs and who should keep them at room temperature?

In SciShow's video, “Should You Store Eggs in the Fridge?” host Hank Green explains where your location and how you get your eggs will determine the best egg safety practices for you.

If you live in the United States, chances are you get your eggs from a grocery store, and you keep them in the fridge. In America, washing and refrigerating eggs helps prevent the spread of Salmonella, which can be transmitted either from an infected hen or manure. Hens are not required to be vaccinated against Salmonella, yet there are approximately 79,000 cases of foodborne illness, and 30 deaths each year are caused by eating eggs contaminated with Salmonella, according to the U.S. Food and Drug Administration (FDA).

However, there are downsides to washing eggs. Typically, when an egg comes out of a chicken, the shell is coated with a protective layer of proteins and other molecules called the cuticle. This layer is designed to keep bacteria like salmonella from getting through the porous eggshell, and setting up inside. Washing eggs gets rid of any dirt, but it also removes the protective cuticle.

In Europe, egg washing is banned. Instead, they rely on cuticles to keep out the bacteria. The Salmonella National Control Programme (NCP) in the U.K. prevents egg operators and producers from marketing eggs infected with the bacteria or that have an “unknown health status” (in other words, not tested, according to the NCP standards), including in other European countries. This means they vaccinate their hens against salmonella.

This is why most countries in Europe leave their eggs at room temperature. Taking an egg out of the fridge will allow condensation to build up on the shell, encouraging bacterial growth, which can find a way through the cuticle and the porous shell.

Meanwhile, in the U.S., it's most likely hens will be contaminated with salmonella, which is why you have to constantly refrigerate eggs, from farms to your home, to slow bacterial growth.

Rule of thumb: if your eggs are pre-washed, keep them in the fridge, unless you want to get Salmonella.