Onions are a versatile vegetable used in many dishes, but once you peel them, it can be tricky to store them properly to maintain freshness. Read on to learn the best ways to store peeled onions.
Should you refrigerate peeled onions?
Refrigeration is not recommended for storing peeled onions. The low temperatures inside the refrigerator will cause the onions to become soft and lose their crisp texture. The cold environment also converts the onions’ sugars into acids faster, giving them an unpleasantly sharp flavor.
How long do peeled onions last at room temperature?
Peeled onions will only last 1-2 days at room temperature before they start to spoil. Leaving them out on the counter any longer risks growth of bacteria that could make you sick. The cut onion also gives off gases that will cause it to deteriorate quickly.
What’s the best way to store peeled onions?
The best way to store peeled onions is in an airtight container in the refrigerator. While refrigeration isn’t ideal, it will extend the onion’s shelf life better than leaving it out. Place the peeled onions in a container with a tight-fitting lid and keep in the fridge for 3-5 days maximum.
Tips for storing peeled onions:
- Use a glass or plastic container, not metal. Metal can give onions a metallic taste.
- Make sure the container has a tight seal to prevent air exposure.
- Layer peeled onions in paper towels inside the container to absorb excess moisture.
- Store the onions towards the front of the fridge where temperature fluctuates less.
What causes peeled onions to spoil faster?
Onions have a high water content and strong aromatic flavors. Once the onion is peeled, several factors accelerate deterioration:
- Exposure to air causes the growth of aerobic bacteria.
- Light exposure accelerates enzymatic browning.
- The cut surfaces release volatile sulfur compounds that affect taste and aroma.
- Moisture is lost through evaporation.
An intact onion outer layer protects the inner layers from excess air, light, and moisture loss. Removing this protective layer leaves the peeled onion vulnerable to all these issues.
Can you freeze peeled onions?
Freezing peeled onions is an excellent way to extend their shelf life. Frozen properly, they can last 6-8 months in the freezer.
How to freeze onions:
- Peel and slice the onions first.
- Blanch sliced onions by boiling for 1 minute, then submerging in ice water.
- Drain and pat dry.
- Place slices on a sheet pan and freeze, then transfer to airtight bags.
- Squeeze out excess air and seal bags.
Frozen onions are best used for cooking rather than eating raw. They’ll retain a decent texture but lose their crisp freshness. Make sure onions are fully frozen before transferring to cold storage bags.
What are the best onion varieties for peeling/storing?
Certain onion varieties hold up better than others when peeled and stored:
- Yellow Onions – Strong flavor stands up well to storage. The most common onion in grocery stores.
- Red Onions – Milder taste best used raw. Don’t store as long as yellow varieties.
- White Onions – Sweet with crisp texture. Often used in Mexican cuisine.
- Sweet Vidalia Onions – Very perishable and prone to mold.
- Shallots – Delicate flavor and peel. Difficult to clean multiple layers.
For best results, choose standard yellow or white onions. Red and Vidalia onions are better used immediately rather than stored long-term.
What are signs of spoiled onions?
Watch for these signs that a peeled onion has gone bad:
- Appearance of mold or black/brown soft spots
- Watery texture
- Translucent look
- Slimy outer layer
- Rotten onion smell
Discard onions immediately if they show any of these signs of spoilage. Do not attempt to wash moldy onions or salvage parts that look edible.
Can you store sliced onions?
Sliced onions have more exposed surface area, meaning they deteriorate even faster than peeled whole onions. For best results:
- Slice onions right before serving for maximum freshness.
- If you must slice in advance, layer between damp paper towels in an airtight container.
- Refrigerate sliced onions and use within 1-2 days.
- Freeze sliced onions if you can’t use them up quickly. Lay flat in a single layer on a sheet pan and freeze, then transfer to airtight bags.
What’s the best onion substitute if you’re out of fresh?
If fresh onions aren’t available, here are some suitable onion replacements:
- Dehydrated onion flakes – Best for cooked dishes, not raw.
- Frozen chopped onions
- Dried onion powder
- Green onions/scallions
- Shallots (milder flavor)
- Asafoetida powder
- Garlic
Dried or frozen onions are closest to fresh in terms of flavor. Garlic and green onions/scallions can provide oniony pungency in a pinch.
Can you store onion skins and scraps?
It’s fine to save onion skins and scraps in the freezer. They can add flavor to stocks, sauces, and soups. Here are some storage tips:
- Keep skins attached to unused onion layers/ends and store together.
- Freeze in resealable bags, squeezing out excess air.
- Use within 3-6 months for best flavor.
- Chop before adding to dishes for easier incorporation.
- Avoid freezing mushy or moldy bits.
Conclusion
With their high moisture content and pungent flavors, peeled onions require special handling to maintain freshness and avoid spoiling. Refrigerate in airtight containers for a few days max, or freeze for 6-8 months. Raw red and sweet onions fare worst, while cooked yellow and white onions hold up best. Handle sliced onions carefully and use promptly. With proper storage methods, you can enjoy onions’ versatility in your cooking, even when peeled and prepped in advance.
