I’m a helicopter parent to most of my produce. Are my leafy greens still perky? Does my basil plant need more sun? But when it comes to onions, I’m cool as can be. I don’t hover, poke, or prod—I just assume they’ll be ready and waiting when I need them.
So it wasn’t until recently, when one of my red onions sitting in a sunny spot in my kitchen started sprouting, that I grew curious. What did this mean, and could I have prevented it? Maybe onions aren’t as invincible as I had previously believed. So I reached out to several onion farmers, a food scientist, and a produce field inspector at Whole Foods to learn some expert tips and tricks for storing onions at home.
Where’s the best place to store onions?
Conventional “storage” onions—which include the white, yellow, and red onions you buy at the grocery store or farmstand—should be kept in a cool, dry space away from direct sunlight, moisture, and heat, says Natalie Alibrandi, a London-based food scientist and CEO of Nali Consulting. This could mean in or under a cabinet away from the stove, or, if you’re buying in bulk, in the mud room or garage. As for what to store them in, good ventilation is key.
“They keep best in mesh bags, paper bags, milk crates, baskets, things of that sort,” says Linda Ly, founder of the gardening and urban homesteading blog Garden Betty.
Organic onions, however, fare better in cooler temperatures, says Justin Rich, co-owner of Burnt Rock Farm, a certified organic produce farm in northwestern Vermont. He recommends storing them in the crisper drawer of the refrigerator.
“Especially later in winter, organic onions will tend to sprout if left for weeks at room temperature, while non-organic onions can hold dormancy much longer,” he says.
Because organic onions aren’t sprayed with a chemical sprout inhibitor, they will often sprout sooner, says Rich. He emphasized the need to keep them refrigerated, especially as they get older, but not to be deterred by a harmless sprout or two.
“The sprout is just a little green onion shoot, so don’t be afraid of it,” he says.
How long will onions last?
Storage onions are cured, which means they’re laid out in a warm, dry place post-harvest until the tops have fully dried and the bulbs have formed a papery skin. The curing process greatly increases storage life; in fact, storage onions kept in the aforementioned conditions will last for about three months, says Stacey Cooper, director of agriculture at Cedar Circle Farm and Education Center, a nonprofit educational organic farm in East Thetford, Vermont.
Once they’ve been cut into, that shelf life greatly decreases—and the onion should be kept in the fridge.
“A halved onion will last in the fridge for about five days,” Cooper says. “Finely chopped or sliced onions tend to dry out and lose their flavor more quickly, and may only last a day or two.”
Is there anything onions shouldn’t be stored near?
You may have been told not to store onions near potatoes, and there’s some science behind that advice, says Randy Davidson, a produce field inspector for Whole Foods.
