Marisa Bunning, a food science and human nutrition professor, spoke to Real Simple about how and when to clean this kitchen staple.
If eggs are store-bought or from a farmers market, she explains washing is not necessary -- and in fact, washing eggs from the store could lead to issues.
"Those eggs are washed in a definitive procedure," she told Real Simple. "It's not a good idea, because washing these eggs could actually lead to problems, especially if someone washed their eggs in really hot or really cold water. The shell is porous. It's just extra work and wastes water."
Eggs do need to be washed when they are backyard eggs. "Consumers aren't used to eggs from their backyard. They're treating them like they're the same, but they're not the same," she says. "If eggs obviously have straw, debris, or manure on them, then you're going to need to clean them."
To properly wash backyard eggs (or eggs you have got from some who raised them in a backyard setting), the food expert says to use warm water, an emery cloth, or a brush. Do not place the eggs on the soil or leave them in standing water. If you need to use a dishwashing liquid, she says to opt for an unscented version and make sure to properly wash off all the detergent.
She also notes eggs bought in America need to be refrigerated and explains in the U.S., people tend to buy more of a product and store it for longer, so keeping them refrigerated is vital. "To me, there's no reason not to refrigerate them. And we say treat them like you do with dairy products. You don't leave your milk or yogurt out for a while. Eggs are the same," she adds.