How Long Do Onions Last and How to Store Them Properly

Onions are the workhorse of the kitchen. They sit in the pantry waiting to be sautéed, caramelized, or diced. But store them wrong, and you’ll end up with a moldy, sprouting mess—and a terrible smell in your cupboard.

Shelf Life Overview

Here is the breakdown based on USDA data:

• Whole Onions (Red, White, Yellow): Last 1 month (30 days) in the pantry.
  • Note: While some data suggests they can last 2 months in the fridge, the humidity often makes them mushy faster. The pantry is preferred.
• Green Onions / Scallions: Last 1 week in the fridge.
• Freezer: Whole onions last 10–12 months frozen (but texture will be soft upon thawing).

How to Tell if Onions are Bad

• The Squeeze Test: A fresh onion is firm. If it feels soft, squishy, or mushy, it’s starting to rot inside.
• Smell: Onions smell like onions, but a rotten onion has a distinct, foul, sour odor.
• Mold: Black powder on the outer skin is common mold. You can wipe it off or peel the skin layer, but if the mold goes deep into the layers, toss it.
• Sprouting: Green shoots mean the onion is trying to grow. It’s safe to eat, but the bulb will be softer and less sweet.

Storage Tips to Keep it Fresh

• Ventilation is Key: Never store whole onions in a plastic bag. They need to breathe. Mesh bags, baskets, or even an old pantyhose leg (classic trick!) work best.
• Darkness: Light encourages sprouting. Keep them in a dark cupboard.
• The Potato Rule: Never store onions next to potatoes. Potatoes release moisture and gas that make onions rot faster, and vice versa.

Can You Freeze It?

Yes.

• Chopped: Dice your onions and freeze them in a bag. No blanching needed.
• Usage: Frozen onions lose their crunch, so use them only for cooked dishes like soups, stews, and sauces—not for raw salsa.

Frequently Asked Questions

How to store cut onions?

Once cut, the smell is potent. Store them in a sealed container or ziplock bag in the fridge for up to 7 days.

Can dogs eat onions?

NO. Onions are toxic to dogs and cats. Even small amounts can cause serious health issues.

Are sprouted onions safe to eat?

Yes. The onion might be a bit softer and the flavor stronger, but you can just cut out the green sprout and use the rest.

Can you freeze chopped onions?

Yes! Chop them up and freeze them flat in a bag. They are perfect for throwing directly into sauté pans later.

How to store whole onions?

Keep them in a cool, dark, well-ventilated place. A mesh bag or basket in the pantry is perfect. Do NOT put whole onions in plastic bags.