Is It Safe to Eat Sprouted Onions?

It's only natural for your onions to eventually sprout, but does that make them unsafe to eat? We have answers! Plus learn how to keep onions from sprouting in the first place.

Imagine going to make pico de gallo for a game night, or a fragrant lentil-and-rice mujadara for a family dinner, only to discover that one of the recipe's most essential ingredients has grown a tail.

A sprouted onion—an onion that has grown a green stalk—won't get up and start running around your kitchen, but it can be a shocking sight, especially if you're not expecting it. Keeping fresh produce in your home is a lot like keeping a house plant: it's still alive and growing, which means it also can die and start decaying.

While most of us don't want to waste food, we also want to make sure that what we are eating won't harm us. Sometimes the signs are pretty clear to read, like when strawberries become moldy or lettuce turns brown and mushy. But sometimes the signs can be misleading, like when you reach for an onion and find that it's grown a bright green tail. You may be left wondering whether it's still safe to eat sprouted onions. Below we answer the age-old question of whether a sprouted onion is safe to eat, what you can do with it and how to prevent sprouting in the first place.

Why Do Onions Sprout?

If you take a look at a fresh onion, you'll notice that it often has bristly hairs on one end, which you usually chop off and discard. Those hairs are the onion roots. But unlike some other plants that spring up directly from the root, onion plants have a bulb—just like lilies and tulips—and that is the part of the plant we normally eat.

And like a flower bulb, an onion isn't the whole plant. Onions grow stems, and sometimes a flower emerges from the top of that stem. When onions are harvested, that stem is cut off as close to the onion bulb as possible, and that's how they're sold at supermarkets. (You may sometimes see stems attached when you purchase onions at farmers' markets.)

So, sprouting a stem is a natural part of an onion's growth cycle, and an onion bulb actually wants to keep sprouting a stem, even after it's hacked off. However, an onion sprouting a stem while in the ground is quite different from one that sprouts a stem in your kitchen. While in the ground, the onion is gaining nutrients from the earth to help it grow, just like any other rooted plant. Removing the onion bulb from the earth halts that process but after a while, when the onion bulb realizes that it's not going back into the ground anytime soon, it starts using its stored sugars and nutrients to sprout another stem. And this is what happens when you see a sprouted onion.

Can You Still Eat an Onion That Has Sprouted?

As for whether or not you can still eat a sprouted onion, Nikki Cervone, associate editor at Foodal, relates, "Hubby and I had a mini fight about this the other day with sprouted garlic. There's nothing toxic or unsafe about consuming either sprouted onions or garlic." She goes on to advise, "I wouldn't use either of them in any raw application, since they're no longer at their 'perfectly prime' state. Other than eliminating a raw application, and perhaps avoiding a recipe where it's the main feature, I have no other limits with a sprouted onion. That ugly duckling will be loved."

The biggest controversy about eating a sprouted onion seems to revolve around its taste and texture. Since the onion bulb uses its stored sugars to sprout a stem, a sprouted onion may taste less sweet and more bitter, especially when raw. And its texture can border on leathery. While some cooks may find the flavor off-putting, others may embrace its strong flavor. Krysia Villon, chef-owner of Chiqui's Kitchen in Newton, Massachusetts, shares, "While it is very strong—like red onions tend to be—I actually like the taste. [It] would be good in a potato salad."

What Can You Do with a Sprouted Onion?

The potentially more-bitter flavor of a sprouted onion is best balanced with intense cooking styles, like charbroiling or frying over very high heat. Ken Basulto, a chef in Miami, Florida, also recommends using sprouted onions in a recipe with a lot of other strong flavors, such as in a batch of kimchi or roughly chopped and mixed with vinegar and chiles to make pique, a type of Spanish Caribbean hot sauce.

You could also make Pickled Red Onions, which can be made with any variety of onion, not just red ones. Just keep in mind that the flavor will be more intense. If you're considering using raw sprouted onions in a dish, you can mellow their flavor by rinsing sliced or chopped onions in water. In the coastal region of Ecuador, this is sometimes referred to as "milking" the onion, because you are rinsing off the milky white, pungent juice that it emits after slicing or chopping it. To mellow them even more, soak them in cold water for 15 minutes.

How Can You Tell If an Onion Is Bad?

When an onion is truly bad—as in it can make you ill or is just plain nasty—the signs are pretty obvious. An onion that is soft to the point of leaving an impression when you press on it should be discarded, as well as onions that are moldy or exuding rancid juices. When you encounter an onion like that, it's best to remove the rest of the produce that it was stored with—including other onions—and examine each one for any moldy, mushy or soft spots. To be on the safe side, it's best to discard the affected produce. Any produce that's still good should be rinsed and scrubbed. We also recommend cleaning and disinfecting the bin or container where the offending onion was stored.

What's the Best Way to Store Onions to Prevent Sprouting?

Moisture, humidity, warmth and light are quite literally an onion's mortal enemies in that they will cause an onion to sprout rapidly and consequently spoil. Cooks who live in warmer, more humid climates may find that storing onions in the refrigerator crisper drawer can prolong their life, as the conditions in their home kitchens might encourage their onions to sprout. Inversely, those who live in dryer and more temperate climates may be able to keep their onions in their pantry or cupboard without them sprouting so soon. And if you live in an area that has very cold winters and hot, humid summers, you may need to adjust how you store your onions seasonally, especially if your kitchen doesn't have air conditioning.

Refrigeration also prevents your onions from getting exposed to light. Like many plants, an exposure to light, especially sunlight, will encourage an onion to sprout. If you don't store your onions in the refrigerator, store them in a dry, cool and dark space like an opaque covered bin or inside a cabinet or cupboard to keep them fresher, for longer.