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- Why Do Onions Sprout?
- Are Sprouted Onions Safe To Eat?
- How Do You Prevent Onions From Sprouting?
You know that fragrant, savory aroma that fills the room when you start cooking dinner? More often than not, we have onions to thank. Onions, or any type of allium for that matter, are the simplest way to build the flavor foundation in a recipe.
They’re also incredibly versatile: you can slowly caramelize their natural sugars, you can pickle them in a punchy brine, and you can fry them into a crispy topping (a green bean casserole truly wouldn’t be the same without them).
Onions are also an extremely hardy vegetable. Civilizations have relied on onions as a food source for millennia, and part of its appeal is its resiliency. When stored properly, certain varieties of onions can last for up to several months. But even with the most careful storage techniques, you can sometimes end up with a sprouted onion.
Sprouts can often indicate that a vegetable is past its prime. And in the case of some types of produce, like potatoes, it may even mean that it’s no longer safe to eat. But what do sprouts mean when it comes to onions? Here's everything you need to know about sprouted onions—safety concerns, its impact on flavor, and how to prevent it from happening.
Sprouting is a natural stage of an onion’s life cycle. They are considered a root vegetable in the culinary world, but botanically they’re technically a bulb. And just like other bulbs (including flowers), onions are essentially the resting stage for a mature onion plant.
Sprouting starts when the onion is exposed to the right growing conditions. It doesn’t necessarily have to be sitting in soil for this to happen. When stored in warm, humid, and/or light-filled spots, onions are basically tricked into thinking it’s spring and start the sprouting process.
Are Sprouted Onions Safe To Eat?
Unlike potatoes, where the mature plant is toxic to humans, all parts of an onion are safe to eat. So you don’t need to worry when you see green sprouts poking out of your produce.
In fact, you don’t even need to remove them. Onion sprouts not the same as scallions or green onions, but they taste pretty darn similar. So feel free to chop them up and use them in your recipes.
Sprouted onions are generally safe to eat, but there are still some important things to know. To provide enough nutrients for the sprouts to grow, the onion uses the sugars that are naturally present in the bulb. This will gradually deplete the pungent sweetness found in a fresh onion. If you’re cooking the onions, it shouldn’t make a major difference. But we’d suggest steering away from raw preparations, since the onions will taste more astringent.
And it should go without saying that you should toss (or compost!) your sprouted onions if they’re mushy, leaking juice, or developing mold.
How Do You Prevent Onions From Sprouting?
The most obvious method to prevent your onions from sprouting is eating them soon after you buy them. But for those of us who buy onions in bulk, you can slow the sprouting with proper storage.
You want to avoid keeping your onions in areas with high moisture levels and temperatures. If you live in a more temperate climate with low humidity, you can store your onions in a dark room like a pantry or closet. But if it’s peak summer and you live in a more humid environment, you’re better off keeping them in the refrigerator.
Gabby Romero
Associate Editor
Expertise: TikTok Trends, Drinks, Pop Culture
Education: B.A. in Journalism and B.S. in Communications from NYU, Culinary Arts degree from The Institute of Culinary Education
About Me: As an associate editor at Delish, Gabby works on everything from features to recipes to content on our social media channels. Before joining the team, she wrote for StarChefs Rising Stars Magazine, Mashed, and Food52. When she’s not developing co*cktail recipes, she’s making co*cktail-inspired dishes like Dirty Martini Pasta and Aperol Spritz Trifle. Her features cover online trends like the Millennial Shopping Cart, rank everything from hard seltzers to frozen French fries, and answer some of your most pressing food safety questions. You can also find her posting content on Delish’s TikTok, including her about cooking like influencer Nara Smith that garnered over 3M combined views. She loves eating spicy food, collecting cookbooks, and adding a mountain of Parmesan to any dish she can.
FAQs
If you're cooking the onions, it shouldn't make a major difference. But we'd suggest steering away from raw preparations, since the onions will taste more astringent. And it should go without saying that you should toss (or compost!)
Why can't you eat sprouted onions? ›
Can You Still Eat an Onion That Is Sprouted? Yes, you can; there's nothing toxic or dangerous about using a sprouted onion. However, sprouting may result in a softer onion with a more bitter taste, which some people find less desirable (especially when eaten raw).
What happens if you put a sprouted onion in the ground? ›
If you notice a green sprout emerging from the top of an onion, it means it's trying to regrow. By separating the sprouts inside an onion's layers and planting them in good soil you can grow multiple new onions within a single season.
Is it bad for onions to sprout? ›
Unlike potatoes, where the mature plant is toxic to humans, all parts of an onion are safe to eat. So you don't need to worry when you see green sprouts poking out of your produce. In fact, you don't even need to remove them. Onion sprouts not the same as scallions or green onions, but they taste pretty darn similar.
How do you know if an onion is unsafe to eat? ›
Spoiled onions may develop dark spots, which will eventually begin to grow mold. You'll also want to avoid onions that have started sprouting, as this indicates they're beginning to go bad. You can also feel your onions to check how fresh they are. Onions with soft or mushy spots are starting to go bad.
How long do onion sprouts last? ›
Your onion sprouts will survive for up to 3 weeks before you need to plant them. You do not need to store them in water or soak them before planting.
Why do onions sprout in the dark? ›
These vegetables use their stored energy to send out shoots. In nature, the shoots would emerge from the soil and start to photosynthesise when they reached the light at the surface. In the refrigerator, however, there is no light, so the shoots keep on growing in a futile effort to find the sun.
How many onions can you grow from one onion? ›
If you plant the whole cut bottom as one piece, you may get more than one new onion but they will likely be crowded together and small. The number of plants a single onion can grow will vary from 1-6, the onion pictured above can be divided into two.
Can I plant a store-bought onion? ›
Planting grocery store onions
When onions start to sprout, they are ready to divide, so that is the best time to plant them. However, if they are really soft with a rotten smell, it's too late. The process of planting our grocery store onions was exceptionally simple.
Should you refrigerate onions? ›
Onions should be stored in a cool, dark place. A temperature range of 45ºF to 55ºF is considered ideal. Whole, raw onions will be kept for up to several months if stored in these conditions. Cellars, pantries, and cool garages all work for onion storage.
Let onion scraps grow roots.
The onion bottoms would rot and mold would grow on the cut surface before any roots developed. Yuk! As much as I LOVE growing things in water, I would always regrow bulb onion scraps in soil because it is so much easier. Place the onion bottoms root side down in a pot filled with damp soil.
Is it OK to cook with sprouted onions? ›
You sure can. A bright green tentacle through the center might look like something out of a sci-fi movie, but there isn't anything dangerous or poisonous about it. The onion will be a bit softer and likely a bit more bitter, but reserving sprouted bulbs for cooked dishes is a simple fix.
Why are my onion sprouts falling over? ›
As maturation proceeds, necks soften and the weight of the leaves causes the tops to fall over. "Tops down" is the physiological response that results from compounds shuttled from the onion's leaves to its scales; consequently, the bulb swells and the tops dry down. The onion is a health food.
Can you eat an onion that has gone to seed? ›
Bolted onions are perfectly edible and although they'll last for a month or so in the ground, they won't store. The best thing to do with bolted onions is to dig them up and eat them right away, or make them into chutney.
Why are my onions sprouting in storage? ›
Keep storage onions in a cool, dark, and dry place. Moisture and light lead to mold (ew) and sprouting (annoying, though not a deal-breaker), so stow your storage onions (red, yellow, and white as well as shallots and the diminutive pearl and cippoline) in a dry, well-ventilated basket, bin, or large bowl.
Why not to eat onion root? ›
Onions may cause symptoms of gastrointestinal upset, such as heartburn, bloating, abdominal discomfort, nausea, and vomiting, in susceptible individuals, which may aggravate symptoms of irritable bowel syndrome in affected individuals. These symptoms are relatively more common when eating onions raw rather than cooked.
Is it safe to eat garlic that has sprouted? ›
The short answer is: sprouted garlic is 100 percent safe to eat, but it has a distinctly different flavor. Besides maybe bad breath, there are no side effects to eating sprouted garlic. They may even have a health benefit, according to a 2014 study that found higher levels of antioxidants in older cloves.
