All About White onion
Your complete guide to white onion - discover how to store it properly, identify when it's gone bad, and find the best substitutes for your recipes.
How Long Does White onion Last?
Storage times and freshness tips for white onion in different conditions.
Safety first: This guide provides general information. When in doubt, throw it out! Trust your senses and err on the side of caution. If something smells, looks, or tastes off, don't consume it.
Cooked Onion in Refrigerator3-4 days
Signs of Spoilage
Off-odor (sour, moldy), visible mold, slimy texture, or unusual discoloration beyond what was present after cooking.
How to Check
Visually inspect for mold or unusual colors. Smell the cooked onions for any sour or unpleasant odors. Check the texture for sliminess.
Storage Tips
Cool cooked onions quickly within two hours of cooking before transferring to an airtight container and refrigerating. This prevents bacterial growth and extends shelf life.
Prepared Raw Onion in Freezer6-8 months
Signs of Spoilage
Significant freezer burn (dry, discolored spots), a very strong, unappetizing odor upon thawing, or a completely mushy texture after thawing. While not unsafe, quality degrades over time.
How to Check
Visually inspect for excessive freezer burn. Note that frozen onions will be softer after thawing compared to fresh. A strong, unpleasant smell upon thawing indicates a significant loss of quality.
Storage Tips
Peel and chop/slice onions as desired. For best results, spread in a single layer on a baking sheet and flash freeze until solid (1-2 hours) before transferring to an airtight freezer bag or container. This prevents clumping and makes it easier to use small portions. Label with the date. Frozen onions are best used in cooked dishes as their texture becomes softer after thawing.
Whole, Uncut Onion at Room Temperature1-2 months
Signs of Spoilage
Soft spots, dark or discolored patches, mold growth (fuzzy white, green, or black spots), sprouting (green shoots emerging from the top), a strong, unpleasant, rotten odor, or a papery, dry outer skin that feels excessively loose.
How to Check
Visually inspect for any discoloration, mold, or sprouts. Gently squeeze the onion to check for soft spots or mushiness. Sniff the onion; it should have a mild, characteristic onion smell, not a pungent, sour, or rotten odor.
Storage Tips
Store in a cool (ideally 45-55°F / 7-13°C), dark, dry, and well-ventilated area. Avoid storing in plastic bags, which trap moisture and accelerate spoilage. A mesh bag or open basket is ideal. Do not store near potatoes, as gases released by potatoes can cause onions to sprout more quickly.
Cut, Raw Onion in Refrigerator7-10 days
Signs of Spoilage
Slimy or mushy texture, strong and unpleasant sour or pungent odor, yellowing or browning of the cut surfaces, or visible mold growth.
How to Check
Visually inspect for sliminess, discoloration, or mold. Touch the onion to feel for any mushy or sticky texture. Smell the onion; a strong, off-putting, sour, or overly pungent smell indicates spoilage.
Storage Tips
Store in an airtight container or a tightly sealed plastic bag in the refrigerator to prevent odor transfer to other foods and to minimize drying out. This also helps maintain freshness.