This time of year, you may bring a bag of potatoes home from the grocery store only to find them sprouting a day or two later. What gives?
Just like humans, those potatoes are ready to get into spring mode after a long winter indoors. Most potatoes that you’ll buy in stores now were harvested last fall and stored at about 40 degrees, according to Mike Wenkel, executive director of the Michigan Potato Industry Commission. Once they’re exposed to light and warmer temperatures in a grocery store, the potatoes go into spring growing mode. The ideal temperature to sprout potatoes is about 70 degrees—pretty close to room temperature in most grocery stores and homes.
“This time of year, it’s going to be really hard to stop that,” he says. “Depending on how severely they’ve sprouted, the potato is converted sugars to starches and trying to build that plant, so it’s pulling energy out of the tuber to do that. But there’s nothing wrong with it from a standpoint of eating it.”
He and other experts including Potatoes USA recommend cutting away the sprouted eyes, and preparing the potato as normal.
“Yes, they’re still safe to eat as long as you pull off the sprouts or the eyes. As long as the potato is still nice and firm, then it’s still pretty good. When it starts to shrivel, the texture gets a little funky, at that point it depends on whether you want to use it or not,” says Kendra Keenan, assistant marketing manager for Potatoes USA.
Depending on the dish you’re preparing, you may need to reach for a crisper potato. Also, resist the urge to refrigerate potatoes: That cold of temperature can cause the tuber to convert its starches to sugars, resulting in a strangely sweet potato.
Another spring phenomenon you might notice is a slight greening of the potato’s skin. That’s caused by the production of chlorophyll, similar to the process that happens in any plant when it’s exposed to the sun.
“Basically it’s the plant photosynthesizing,” Wenkel says. “You could cut that green skin away as well. If you eat it, it’s going to be very bitter.”
Greening potatoes produce not just chlorophyll but also solanine, which is a known toxin. You’d have to eat quite a bit of green potato to get sick—about a fully green baked potato, according to The New York Times Science Desk—but if that potato isn’t going to taste great anyway, why risk it?
Bottom line: Sprouted potatoes are fine as long as you’ve cut the sprouts off and made sure they’re not too mushy. For green potatoes, cut off any small discolored areas. If they’re fully green, you may as well go buy a fresh bushel.