The Fascinating Reason Grocery Stores Cover Potatoes At Night (And You Should Too)

You never forget the first time you walk through a grocery store near their closing time and spot a pile of potatoes tucked under a blanket. It's certainly a strange sight, but no, they're not being tucked in and read a goodnight story for coziness alone. The potatoes are being covered with a blanket to prevent them from getting too much light, because light causes spuds to turn green and start to taste bitter. Research examining potato displays in retail stores found that because many stores leave their produce under lights for long periods, giving spuds an overnight tuck-in under a blanket or cover is a clever way to reduce that exposure over time, per an article published in the PLOS One journal.

Potatoes are very responsive to light — it's what triggers the production of chlorophyll (yes, the same green pigment found in plant leaves), which turns them that slight tinge of green you'll have seen on potatoes at one time or another. And it could signal an increase in compounds called glycoalkaloids, which can cause illness in humans at high concentrations.

The grocery store blanket trick also works once you've brought your potatoes home. No, you don't have to take your blankets out of their storage boxes, but you should always keep potatoes in a dark, cool, and well-ventilated place rather than on a sunny kitchen counter. It's common to store potatoes in paper bags, cardboard boxes, or breathable storage containers (like mesh bags), as these can all help block out some light, too. They don't need to be fully wrapped up like you're about to bake them; it's just about keeping as much direct light away as you can.  

And this whole premise ties into why the fridge is one of the worst places in your kitchen to store potatoes. It's cold and moist in there, which may not be ideal for potatoes, and it also has a light that turns on every time you open the door to peek your head inside. If you want your potatoes to last as long as possible, they shouldn't be in the fridge, on the counter, or cluttering a windowsill. And if your potatoes are already sprouted or have developed large green areas, then you're better off just discarding them and adapting better storage habits from here on out.