Do onions go bad? – What you need to know
Onions are a staple ingredient in many cuisines around the world, known for their distinct flavor and versatility in a variety of dishes. However, like all perishable foods, onions will eventually go bad if not stored properly. In this article, we will explore the factors that contribute to onion spoilage, how to tell if an onion has gone bad, and the best practices for storing onions to ensure their longevity.
Understanding Onion Spoilage
Onions, whether whole, cut, or in the form of green onions or scallions, will eventually spoil over time. However, the rate at which onions spoil can vary depending on several factors, including storage conditions and the type of onion.
Whole Onions
Whole onions may begin to sprout green stems as they age. While these sprouts are safe to eat, they indicate that the onion is getting older and may have dry or rubbery outer layers that need to be removed. In addition, whole onions may dry out and shrink with prolonged storage. In such cases, peeling back a few layers may reveal fresh, crisp layers inside, but the overall quality of the onion will deteriorate the longer it is stored.
The worst-case scenario for whole onions is mold growth, which results in a slimy, mushy, and unpleasant smelling texture. Mold growth is usually caused by moisture getting into the storage area. Therefore, it is important to store whole onions in a cool, dry place to prevent mold growth.
Cut onions
Once an onion has been cut or sliced, it is more susceptible to spoilage. Cut onions should be refrigerated in an airtight container or sealable bag to keep them fresh. If left unrefrigerated, cut onions will eventually spoil.
Green Onions and Scallions
Green onions and scallions, which are different types of onions with a higher water content, require refrigeration to maintain their freshness. These varieties should be stored in the refrigerator, preferably in a plastic bag with some holes to allow air circulation.
Identifying spoiled onions
To avoid eating spoiled or potentially harmful onions, it is important to know how to tell when an onion has gone bad. Here are some signs to look for:
Discoloration and dark spots
If you notice dark brown or black areas on the outer layers and skin of an onion, it indicates that the onion is rotten or has dried out beyond the point of being appetizing. Onions should always be firm, without soft spots, sponginess, or bruising. While the outer layers of an onion may be dry and papery, excessive peeling of the soft layers is a sign of spoilage and such onions should be discarded.
Onion mold
The presence of black mold on the outer surface of an onion is not uncommon. This mold is caused by a fungus commonly found in soil. If you notice mold on an onion, remove the affected parts and put the rest of the onion in the refrigerator. Peeling, rinsing, and using the onion promptly can help reduce the spread of mold. However, if the mold has penetrated multiple layers of the onion, it is advisable to discard the entire onion to avoid potential health risks.
White liquid
When an onion is sliced, it releases a milky white liquid that is a natural occurrence and not a sign of spoilage. The liquid results from the combination of stored moisture, natural sugars and starches in the onion. The presence of this liquid is not a health concern unless there are other visible signs of spoilage.
Can bad onions make you sick?
While eating spoiled food can potentially make you sick, bad onions are not overly dangerous or likely to cause food poisoning. If you discover that an onion has gone bad, you can remove the affected area and safely consume the rest. In the rare event that you do eat a piece of spoiled onion, it may taste bad and cause minor stomach discomfort, but it is unlikely to cause serious or permanent damage.
Best practices for storing onions
Proper storage is critical to extending the shelf life of onions. Here are some best practices to help keep your onions fresh for as long as possible:
Temperature
Whole onions should be stored in a cool place. A pantry or cupboard is ideal, as long as it is not directly adjacent to a heat source such as an oven, or exposed to extreme cold in a basement or cellar. The optimal temperature range for storing onions is between 60-70°F (15-21°C).
Humidity
Moisture is the enemy of onion storage. To prevent mold growth, it is critical to keep onions in a dry environment. Avoid storing them in areas of high humidity, such as the refrigerator, as excess moisture can lead to premature spoilage.
Air Circulation
Onions need proper air circulation to keep them fresh. Avoid sealing them in airtight containers, which can trap moisture and promote mold growth. Instead, store onions in mesh bags, wire baskets, or open containers that allow air to circulate around them.
Avoid storing with certain foods
Onions release ethylene gas, which can accelerate the ripening and spoilage of certain fruits and vegetables. To prevent this, store onions separately from produce such as potatoes, apples, and bananas that are sensitive to ethylene exposure.
Avoid storing in plastic bags
Plastic bags can trap moisture and promote spoilage. Instead, opt for breathable storage solutions such as mesh or paper bags. These materials allow for better air circulation and help prevent mold growth.
Inspect regularly
Inspect your onions regularly for signs of spoilage. Remove any onions that show signs of mold, soft spots, or excessive drying. By regularly inspecting your onion supply, you can prevent the spread of spoilage to other onions and ensure that you use them before they go bad.
Bottom line
In summary, onions can and will spoil over time if not stored properly. Whole onions can sprout green stems, dry out, or develop mold if exposed to moisture. Cut onions, as well as green onions and scallions, require refrigeration to maintain freshness. It is important to recognize signs of spoilage, such as discoloration, mold, or excessive drying, and to discard any onions that exhibit these characteristics. By following onion storage best practices, including maintaining proper temperature, humidity, and air circulation, you can extend the shelf life of your onions and enjoy their flavor and versatility in your culinary creations.
FAQS
How long do onions stay fresh when stored properly?
When properly stored in a cool, dark place, onions can remain fresh and edible for up to three months.
Can I eat an onion that has started to sprout?
Yes, you can eat an onion that has started to sprout. However, the sprouted onion may have dry or rubbery outer layers that need to be removed.
What should I do if my whole onions are dry and shriveled?
If your whole onions have dried out, you can try peeling back a few layers to see if there are fresh, crunchy layers inside. However, the overall quality of the onion will deteriorate the longer it is stored, so it is best to use them before they become too shriveled.
Are chopped onions more likely to spoil?
Yes, once an onion has been cut or sliced, it is more susceptible to spoilage. It is important to refrigerate cut onions in an airtight container or sealable bag to keep them fresh.
Can green onions and scallions spoil?
Yes, green onions and scallions can go bad if not stored properly. The best way to keep them fresh is to store them in the refrigerator, preferably in a plastic bag with a few holes for air circulation.
Can eating bad onions make me sick?
While eating spoiled food can potentially make you sick, eating spoiled onions is unlikely to cause serious illness. However, if you notice signs of spoilage, such as mold or an unpleasant odor, it is advisable to discard the onion to avoid any potential health risks.