Onions are a versatile vegetable used in cuisines around the world. With their long storage life, onions are often bought in bulk for continual use over weeks or months. However, improper storage can lead to spoilage, sprouting, and waste. Use these tips to learn how to store onions correctly and enjoy their fresh flavor as long as possible.
The Basics of Onion Storage
Before diving into specific techniques, understand these basic guidelines that are essential for proper onion storage:
Choose Firm, Unblemished Bulbs Shape
Select onions that are heavy for their size with crispy, crackling outer skins. Avoid any with soft spots, green sprouts, or dark moldy patches.
Allow onions to Cure After Harvesting
Curing removes excess moisture and helps form protective outer skins. Leave harvested onions in a single layer to dry for 1-2 weeks.
Store in Cool, Dark, Dry Conditions
Onions last longest in temperatures just above freezing with low humidity and no light.
Provide Good Airflow
Onions release gases during storage. Ensure storage containers or areas have ample ventilation.
Check Frequently for Problems
Inspect onions weekly and remove any that are sprouting or show signs of mold.
Follow these guidelines as the basis for any onion storage method.
Storing Whole Onions
Keeping onions in their original bulb form is a common approach. Follow these tips for success:
Braid Tops and Hang : After curing, braid onion tops together and hang in a dry pantry or cellar. Keeps for 2-4 months.
Place in Mesh Bags : Cured onions can be held in mesh or burlap bags. Hang or set on shelves. Replenish bags as needed.
Use an Open Crate or Basket : A ventilated crate or basket with a single layer of onions works for small batches. Place in a cool cupboard or cellar.
Store in Refrigerator : While not ideal, onions can be kept loose in refrigerator drawers. Use within a few weeks as cold diminishes flavor over time.
With any of these methods, check onions frequently and remove any that show signs of spoiling. Use whole onions within a 2-4 month period for best flavor.
Storing Onion Halves
Cutting an onion in half extends its usability in storage. Follow these recommendations:
Leave Root End Intact : When cutting an onion in half horizontally, leave the small dry roots attached to one half. This protects against spoilage.
Wrap Tightly in Plastic Wrap : Wrap each half separately in plastic wrap, squeezing out excess air. Refrigerate for up to 2 weeks.
Place Cut-Side Down in Airtight Container : Put onion halves cut-side down in a lidded container like Tupperware. Keeps for 1-2 weeks refrigerated.
Store in Resealable Plastic Freezer Bags : Halved onions can be frozen successfully for longer storage. Double bag and remove air prior to freezing.
Pickle in Vinegar : Soaking onion halves in vinegar creates a quick pickle that lasts for months refrigerated. Use white, cider, or rice vinegar.
Taking the extra step to cut onions in half makes it easy to store and use smaller portions over time.
Freezing minced or Chopped Onions
For maximum convenience, onions can be frozen after chopping or mincing. Here are some recommendations:
- Place in Freezer Bags : Divide chopped onions into typical recipe amounts and put in labeled freezer bags. Flatten to remove air before sealing.
- Freeze in Ice Cube Trays : Minced onions can be frozen in ice cube trays for easy use later. Pop out cubes into a freezer bag once frozen.
- Mix with Olive or Vegetable Oil : Coat chopped onions with a bit of oil before freezing in bags or containers to prevent freezer burn.
- Blanch Before Freezing : Boiling onions 1-2 minutes before freezing helps them retain flavor and texture better. Drain, pat dry and cool before freezing.
- Add to Dishes Before Freezing : Use frozen onions in cooking by adding to sauces, soups, casseroles, etc. before freezing the whole dish.
Freezing is the most long-term onion storage method. Frozen onions can be kept 6-8 months.
Ideal Storage Conditions for Maximum Shelf Life
To get the most out of stored onions, be sure to utilize optimal storage conditions:
- Temperature between 35-40°F – Colder than a refrigerator. An unheated basement, cellar, or garage often works well.
- Low humidity around 60-70% – Prevent mold growth by avoiding damp storage areas.
- Good air circulation – Onion gases can lead to spoilage if trapped. Keep loosely packed.
- Dark storage area – Light causes sprouting in onions. A dark basement or opaque containers work best.
- Intact outer skins – Don’t wash or peel onions prior to storage, the dry outer skin protects the bulb.
Aim for cool, dark, dry storage to enjoy fresh onions for months beyond the end of the growing season.
Signs of Onion Storage Problems and What to Do
Even with optimal storage , onions can occasionally run into issues. Watch for these problems and take corrective action:
Sprouting – Small green shoots indicate the onion is past its prime. Use sprouted onions immediately.
Mold – Fuzzy black or white mold is a sign of excess moisture. Wipe off mold and improve conditions.
Shriveling/drying – Severe shriveling means dehydration. Try sealing in plastic bags to boost humidity.
Soft spots – Discard any onions with dark, mushy patches as they may spoil the bunch.
Strong onion odor – A very strong smell indicates onset of spoilage. Use the onion or remove from storage.
By regularly checking stored onions and troubleshooting issues, you can avoid significant losses.
Enjoying Onions Year Round
With the proper storage techniques, onions can be kept for use over many months. Follow these tips to always have onions on hand:
- Store a variety of onion types – Mix sweet, yellow, red, and white onions for maximum versatility in cooking.
- Replenish from each harvest – Let storage onions last as long as possible, then replace with new crop.
- Freeze some prepped onions – Have chopped and minced onions ready to grab from the freezer.
- Use older onions first – Bring oldest onions up from storage to use next. Follow a “first in, first out” system.
Share extras before spoiling – Onions make great gifts for fellow gardeners and foodies!
Learning how to store onions gives you an extended seasonal supply of this essential vegetable. Implement proper curing, storage methods, and ongoing monitoring to maximize freshness and eliminate waste.