If an onion is halved, sliced, or chopped, it’s best to keep it in the fridge, preferably in an airtight container. Cutting into an onion drastically reduces its shelf life, and you should only keep cut onions for up to a week in the refrigerator. Whether they are whole or cut, storing onions properly helps prevent foodborne illness associated with onion spoilage.
Why Proper Onion Storage is Important
Spoilage or contamination of any food can lead to foodborne illness, and onions are no exception. As recently as 2023, a contaminated brand of fresh diced onions was linked to a salmonella outbreak across the United States and recalled by the FDA.
Rotten onions promote bacterial growth linked to the development of several foodborne illnesses, including:
- Salmonella – Salmonella is common in raw vegetables. Sometimes fatal in serious cases, it typically causes vomiting, diarrhea, and muscle aches. Severe salmonella can also lead to sepsis and osteomyelitis, a bone infection.
- E. coli – E. coli is a common foodborne bacteria in raw vegetables that causes bloody stool, abdominal cramps, diarrhea, and vomiting.
- Campylobacter – Campylobacter is commonly found in raw vegetables. It causes campylobacteriosis, one of the most common foodborne illnesses in the United States, which leads to vomiting, diarrhea, and, in some cases, death.
Safely Storing Onions
Store onions differently depending on the type and whether they’re whole or cut.
How to Store Whole Onions
Whole onions last much longer than cut or chopped onions. If stored correctly, you can keep whole onions for extended periods without issues. Store whole onions in a cool, dry, ventilated place to protect them from spoilage, mold, and drying out.
Onions can be safely stored at 30–50°F for up to one year. Peeling a whole onion reduces its shelf life significantly. You should always store peeled whole onions in the fridge, where they can last from 10 to 14 days.
How to Store Cut Onions
After cutting onions, always store them in the fridge, preferably in a sealed, airtight container. Storing your onions in an airtight container minimizes the likelihood that the onion will dry out or become contaminated in the refrigerator. You should put chopped or diced onions in the fridge within two hours of cutting them to minimize possible bacteria growth.
How Long Do Onions Last After Cutting?
Typically, a halved, sliced, or diced onion stays good in the fridge for roughly seven to ten days when in an airtight container. Improperly stored onions have a much shorter shelf life and are prone to drying out or becoming slimy.
Storing Different Types of Onions
Different types of onions have different needs when it comes to storage.
How to Store Yellow and White Onions
Yellow and white onions are commonly known as “storage onions” because you can keep them for a long time. Store them in cool, dry, ventilated environments out of direct sunlight. If stored correctly, yellow and white onions can stay safe to eat for months.
How to Store Red Onions
Red onions are stored similarly to yellow and white onions, but they tend to have a shorter shelf life. Keep an eye on your red onions and periodically ensure they’re still safe to eat before using.
How to Store Green Onions
Green onions (scallions) are much less pantry-friendly than other types of onion and have a significantly shorter shelf life. However, if stored with their roots in a jar of water, green onions can grow continuously if the roots stay intact. Use the greens as needed, and preserve the roots.
If you’re planning to only use them once, store green onions in a jar of water in the fridge to maximize their shelf life. This method will generally keep them fresh for up to three weeks.
How to Know When Onions Have Gone Bad
A telltale sign of spoilage is a soft spot on the top of an onion. This generally indicates internal rot and that it’s time to throw the onion away.
A strong, putrid smell is also a common sign of spoilage. While many fresh onions have a strong aroma, it’s hard to miss the stench of a rotten onion. If your onion smells conspicuously bad or somehow “off,” don’t risk it. Simply throw it away.
Surface mold is never safe to eat on any food and is a definite sign your onion is past its expiration date. Don’t cut off mold and eat the rest of the onion. Mold contamination runs deep, and cutting off visible mold doesn’t mean your onion is safe to eat.
A sprouting onion doesn’t necessarily indicate that an onion has spoiled. However, it does indicate that an onion is aging and may soon not be safe to eat. Use caution when eating sprouting onions.
Contact Keep Food Safe to Connect With an Attorney
If you contracted a foodborne illness after eating onion, unsafe packaging, careless handling, or negligent restaurant preparation may be to blame. Keep Food Safe is dedicated to protecting consumers and helping them understand their legal rights. Contact us today to learn more and connect with a skilled food safety lawyer.
