Do You Put Eggshells Back in the Carton? Maybe You Shouldn’t
Do you do this, too? I don't know if anyone taught me about putting shells back in the carton but always have ever since I can remember. It wasn't even something my parents did, just sometime I did. Not sure. I've been doing this for years but, as I've come to find out, I need to stop.
According to EggSafety.org, you should never do this for several reasons. Namely, bacteria reasons. With the chance of bacteria spreading from the broken shell to the uncracked shell, the chance is too high to risk.
I know, it's so much easier to get the whole carton, crack eggs as needed and just put the shells back in the carton to place back in the fridge until they're all used so you can toss or compost everything, but best to put those shells straight in the trash or compost for safety's sake.
That goes for the carton, too. They advice you don't reuse cartons as that type of paper-material can't be washed and could be a breeding ground for bacteria.
You can read more at eggsafety.org.