How Long Do Onions Last in the Fridge? Complete Storage Guide

Onions are a fundamental ingredient in countless recipes, but knowing how to store them properly can be confusing. While many people automatically refrigerate all their produce, onions actually require different storage methods depending on their state. Understanding how long onions last in the fridge—and when refrigeration is even appropriate—can help you reduce food waste and keep your onions fresh longer.

The answer to how long onions last in the fridge depends entirely on whether they’re whole, peeled, cut, or cooked. Let’s explore the optimal storage times and methods for each type.

Should Whole Onions Be Stored in the Fridge?

Here’s a surprising fact: whole, unpeeled onions should not be stored in the refrigerator. Despite what your instincts might tell you, the fridge is actually the worst place for intact onions with their papery skin still on.

Whole onions are best kept in a cool, dry, dark, and well-ventilated location such as a pantry, basement, or garage. The ideal temperature range is between 40-50°F (4-10°C). When stored properly in these conditions, whole onions can last 2-3 months or even longer.

Why avoid refrigerating whole onions? The refrigerator’s cold, humid environment causes onions to absorb excess moisture through their skin. This leads to several problems:

• The onions become soft and mushy
• They spoil much faster than they would at room temperature
• They may develop mold more quickly
• The texture and flavor deteriorate

Store whole onions in mesh bags, open baskets, wire baskets, or netted bags to ensure adequate air circulation. Never keep them in plastic bags, which trap moisture and accelerate spoilage.

How Long Do Peeled Onions Last in the Fridge?

Once you’ve removed an onion’s papery outer skin, the storage rules change completely. Peeled whole onions must be refrigerated to prevent bacterial contamination.

Storage time: 10-14 days

To properly store peeled onions:

1. Place the peeled onion in an airtight container or resealable plastic bag
2. Ensure your refrigerator is set to 40°F (4°C) or below
3. Keep away from foods that easily absorb odors
4. Label with the date to track freshness

Peeled onions are more vulnerable to bacterial growth because the protective outer layers have been removed, exposing the moist inner flesh to potential contaminants. Refrigeration slows bacterial growth and helps maintain quality.

How Long Do Cut, Sliced, or Diced Onions Last in the Fridge?

Cut onions have an even shorter refrigerator life than peeled whole onions due to the increased surface area exposed to air and potential bacteria.

Storage time: 7-10 days

Follow these steps for storing cut onions:

• Place sliced, diced, or chopped onions in an airtight container immediately after cutting
• Alternatively, wrap tightly in plastic wrap or aluminum foil
• Store in the main body of the refrigerator, not the door (where temperature fluctuates)
• Use within one week for best quality and flavor

You’ll notice that cut onions have a strong odor that can permeate your refrigerator. Using airtight containers helps minimize this issue and prevents your other foods from absorbing onion flavors.

For visual reference, if your cut onions start to develop a slimy texture, darkened edges, or an off smell, they’ve gone bad and should be discarded immediately.

How Long Do Cooked Onions Last in the Fridge?

Cooked onions—whether sautéed, caramelized, grilled, or roasted—have a shorter refrigerator life than raw onions.

Storage time: 3-5 days

Proper storage for cooked onions:

1. Allow cooked onions to cool to room temperature (but don’t leave out longer than 2 hours)
2. Transfer to an airtight container or resealable bag
3. Refrigerate promptly at 40°F (4°C) or below
4. Reheat thoroughly before consuming again

Cooked onions are excellent for meal prep. You can sauté or caramelize a large batch on the weekend and use them throughout the week in various dishes like omelets, sandwiches, pizzas, or pasta.

How Long Do Different Types of Onions Last in the Fridge?

Different onion varieties have varying storage requirements and lifespans.

Yellow Onions

These are the most common variety and have a papery golden-brown skin. Whole yellow onions should be stored in a cool, dark pantry rather than the fridge, where they’ll last 2-3 months. Once cut, refrigerate for 7-10 days.

Red Onions

Red or purple onions have a slightly sweeter, milder flavor. Storage guidelines are identical to yellow onions: keep whole onions in a pantry (2-3 months) and refrigerate cut pieces (7-10 days).

White Onions

White onions have thinner skin and higher water content, making them more perishable. Whole white onions last 1-2 months in proper pantry storage. Once cut, refrigerate and use within 7-10 days.

Sweet Onions (Vidalia, Walla Walla, Maui)

Sweet onions have higher sugar and water content, making them more delicate. Interestingly, sweet onions are an exception to the no-refrigeration rule. You can refrigerate whole sweet onions wrapped individually in paper towels, where they’ll last 1-2 months. Once cut, they last 7-10 days refrigerated.

Shallots

These small, elongated onions should be stored like regular onions—in a cool, dry place for up to 30 days. Peeled shallots can be refrigerated in an airtight container for about 2 weeks.

How Long Do Green Onions and Scallions Last in the Fridge?

Green onions (also called scallions or spring onions) are entirely different from storage onions and require refrigeration from the start.

Storage time: 1-2 weeks

Best storage methods for green onions:

Method 1: Paper Towel Method

• Wrap green onions in a slightly damp paper towel
• Place in a plastic bag or container
• Store in the crisper drawer
• Lasts 1-2 weeks

Method 2: Water Glass Method

• Trim the roots slightly (optional)
• Place the white ends in a glass with 1-2 inches of water
• Cover loosely with a plastic bag
• Store in the refrigerator
• Change water every few days
• Lasts 1-2 weeks (the green onions may even continue growing!)

Method 3: Counter Method

• Place green onions in a glass with water (roots down)
• Keep on a sunny windowsill
• Change water daily
• Lasts 3-5 days (best for immediate use)

Freezing Onions: Extended Storage Solution

If you can’t use your onions within the refrigerator storage times, freezing is an excellent option for long-term preservation.

How Long Do Frozen Onions Last?

Storage time: 3-6 months (up to 12 months for best quality)

How to Freeze Raw Onions

1. Peel and chop onions to your desired size
2. Spread in a single layer on a parchment-lined baking sheet
3. Flash freeze for 2-3 hours until solid
4. Transfer to freezer bags or airtight containers
5. Label with date and contents
6. Remove excess air before sealing

Pro tip: Freeze onions in pre-measured portions (like 1/2 cup or 1 cup amounts) for easy recipe use.

How to Freeze Cooked Onions

Caramelized or sautéed onions freeze exceptionally well:

1. Cook onions completely and let cool
2. Portion into freezer-safe containers or bags
3. Freeze flat for space-saving storage
4. Use within 3 months for best flavor

Using Frozen Onions

Frozen onions work best in cooked dishes. They lose their crisp texture when frozen, making them unsuitable for raw applications like salads or garnishes. However, they’re perfect for:

• Soups and stews
• Casseroles and baked dishes
• Sauces and gravies
• Stir-fries
• Omelets and scrambled eggs

No need to thaw frozen onions before cooking—add them directly to your hot pan or pot.

How to Tell If Onions Have Gone Bad

Knowing when to discard onions is crucial for food safety. Here are clear signs that your onions are no longer safe to eat:

Visual Signs

• Mold growth: Any fuzzy spots, black spots, or visible mold means the onion should be thrown away entirely
• Dark spots: Brown or black soft spots indicate rot
• Excessive sprouting: Small green shoots are okay to remove, but extensive sprouting means the onion is past its prime
• Slimy texture: A slimy or mushy outer layer indicates bacterial growth
• Shriveling: While slightly soft onions can still be used, extremely shriveled onions have lost too much moisture

Smell Test

Fresh onions have a sharp, clean smell when cut. Bad onions emit a sour, rotten, or unpleasant odor even before cutting. If an onion smells off, trust your nose and discard it.

Texture Check

Onions should feel firm and heavy for their size. If they feel soft, mushy, or unusually lightweight, they’ve likely gone bad.

What About Sprouted Onions?

Onions with small green shoots are still safe to eat. Simply cut the onion in half, remove the green sprout from the center, and use the rest normally. However, sprouted onions have a more bitter flavor and softer texture, so they’re best used in cooked dishes rather than eaten raw.

Tips for Maximizing Onion Freshness

Follow these expert strategies to keep your onions fresh as long as possible:

1. Buy Fresh, Quality Onions

Start with the best quality onions. Choose onions that are:

• Firm and heavy for their size
• Have dry, papery skin with no soft spots
• Free from bruises, cuts, or moisture
• Have no smell (onions shouldn’t smell until cut)
• Have tight, dry necks (the top part)

2. Keep Onions Separate from Potatoes

This is a critical tip that many people don’t know: never store onions and potatoes together. Potatoes release moisture and gases that cause onions to spoil faster. They also accelerate each other’s sprouting. Store them in separate, well-ventilated areas.

3. Ensure Proper Air Circulation

Onions need to breathe. Use:

• Mesh bags
• Wire baskets
• Netted produce bags
• Open wooden crates
• Paper bags with holes punched in them

Avoid plastic bags or airtight containers for whole onions, as trapped moisture promotes mold and rot.

4. Maintain Ideal Storage Temperature

The sweet spot for whole onion storage is 40-50°F (4-10°C) with low humidity. A basement, cellar, or garage often provides these conditions better than a kitchen pantry.

5. Keep Them Dark

Light exposure can cause onions to become bitter and sprout more quickly. Store in a dark cabinet, drawer, or covered container.

6. Use the First-In, First-Out Method

When you buy new onions, move older ones to the front and place new ones in back. This ensures you use the oldest onions first, reducing waste.

7. Check Regularly for Spoilage

Inspect your onion storage weekly. Remove any onions showing signs of rot immediately, as one bad onion can quickly affect others nearby.

8. Consider Buying Smaller Quantities

Unless you use onions very frequently, buying smaller amounts more often may result in less waste than buying in bulk.

How to Store Pickled Onions

Pickling is an excellent preservation method that extends onion shelf life significantly while adding delicious tangy flavor.

Unopened pickled onions: 1 year in the pantry

Opened pickled onions: 2-3 months in the refrigerator

Homemade pickled onions: 2-4 weeks in the refrigerator

Quick-pickled onions (made with vinegar, salt, and sugar) should always be refrigerated and used within 2-4 weeks. They’re perfect for topping tacos, sandwiches, salads, and bowls.

Special Storage Considerations for Leeks

Leeks are related to onions but require different storage:

Storage time: 1-2 weeks in the refrigerator

To store leeks:

1. Do not wash until ready to use (moisture causes decay)
2. Wrap loosely in a plastic bag
3. Store in the crisper drawer
4. Keep the roots intact for longer freshness

Unlike regular onions, leeks should be refrigerated from the start. They’re more delicate and will wilt quickly at room temperature.

Food Safety Considerations

Proper onion storage isn’t just about quality—it’s also about safety.

The Two-Hour Rule

Never leave cut or cooked onions at room temperature for more than 2 hours (1 hour if the temperature is above 90°F). Bacteria multiply rapidly in this temperature “danger zone” between 40-140°F.

Cross-Contamination Prevention

• Always use clean cutting boards and knives when cutting onions
• Wash hands thoroughly before and after handling onions
• Don’t use the same cutting board for onions and ready-to-eat foods without washing it first
• Store cut onions away from ready-to-eat foods in the refrigerator

When in Doubt, Throw It Out

If you’re unsure whether an onion is still good, it’s better to be safe than sorry. The small cost of replacing an onion is worth avoiding potential foodborne illness.

Frequently Asked Questions About Storing Onions in the Fridge

Can I store onions in the fridge door?

No, the refrigerator door experiences the most temperature fluctuation, which can shorten the storage life of cut or peeled onions. Store them in the main body of the fridge instead.

Why do my onions make my fridge smell?

Onions release sulfur compounds, especially when cut. Use airtight containers or double-bag them to minimize odor. Placing an open box of baking soda in your fridge also helps absorb odors.

Can I freeze whole onions?

While you can technically freeze whole onions, it’s not recommended. The texture becomes very mushy when thawed. It’s much better to peel and chop them before freezing.

Do onions last longer in the fridge or pantry?

Whole, unpeeled onions last much longer in a cool, dark pantry (2-3 months) than in the fridge. However, once peeled or cut, onions must be refrigerated and will last 7-14 days.

Can I eat an onion that has been in the fridge for a month?

If it’s a whole, unpeeled onion that was mistakenly refrigerated, check it carefully for signs of spoilage. If it’s still firm and shows no mold or soft spots, it’s likely still safe to use. However, if it’s a cut or peeled onion that’s been refrigerated for a month, it should be discarded.

How do I prevent my other food from tasting like onions?

Use airtight containers for storing cut onions, and keep them away from foods that easily absorb odors, such as dairy products, eggs, and soft fruits.

The Bottom Line

Understanding how long onions last in the fridge depends on knowing which onions should be refrigerated in the first place. Whole, unpeeled onions are best stored in a cool, dark, dry pantry where they’ll last 2-3 months. Once peeled or cut, onions must be refrigerated and will last 10-14 days (peeled) or 7-10 days (cut). Cooked onions keep for 3-5 days refrigerated.

For long-term storage, freezing is your best option, extending shelf life to 3-6 months. Green onions and leeks are exceptions to the rule and should always be refrigerated, lasting 1-2 weeks with proper storage.

By following these guidelines and storage tips, you’ll minimize food waste, save money, and always have fresh onions ready for your favorite recipes. Remember to inspect your onions regularly, use proper storage containers, and trust your senses—if an onion looks, smells, or feels off, it’s time to let it go.

Sources:

• USDA Food Safety and Inspection Service
• FDA – Buy, Store & Serve Safe Food
• National Onion Association
• FoodKeeper App – USDA
• CDC Food Safety