How to Preserve Onions

Store onions harvested in late autumn. Onions harvested in spring and summer are not sturdy enough for long-term storage. These types of onions should be used within a few weeks of harvest. It’s best to store onions harvested in the fall, as these varieties can withstand winter conditions.

• If growing onions yourself, store those planted in the spring.
• You can harvest onions for storage in late summer or early autumn, when the tops begin to droop and dry out.

Store pungent onions. Unlike sweet onions, pungent onions contain sulfur compounds that cause tearing when cut, which also helps preserve them through winter. Sweet onions lack this natural preservation mechanism, so they should be used within weeks of harvest. The following onion varieties are excellent for storage:

• Yellow onions such as ebenezer, yellow globe, downing yellow globe, and yellow globe danvers.
• White onions like Southport white globes. These should only be stored if they have small tops.
• Red onions, including wethersfield and Southport red globe.

Dry the onion skins. After harvesting, spread the onions in a well-ventilated area to allow the skins to harden. Do not remove the leaves. Let the onions dry for 2-4 weeks.

• Dry the onions in a shaded, moisture-free area. Sunlight can damage their flavor, making them bitter. Use a tarp in a garage or shed for drying. The area should be dry, warm, and airy.
• Onions are dry when the tops are no longer green. The skins will shrink around the stem and tightly wrap the bulb.

Trim the onions. Once the tops are completely dry, use sharp scissors to cut off the roots.

• Discard onions with green stems at this stage, as well as those with bruises or cracks.
• Trim the leaves to at least 2.5 cm above the bulb, or leave them intact and braid them together.

Choose a cool, dark place for onion storage. The storage area should maintain a temperature between 4-10°C. Many people use basements for storing onions. If the temperature is too warm, the onions may sprout. If it’s too cold, they may rot.

Keep the storage area dry. Onions easily absorb moisture, and humidity can spoil them. Maintain humidity levels between 65-70%.

Ensure proper ventilation in the storage area. Air circulation around the onions helps prevent mold and decay.

• To maintain airflow, store onions in mesh baskets, net bags, or pantyhose and hang them up.
• If using pantyhose, tie a knot between each onion. Use the onions at the bottom first by cutting below the knot to avoid disturbing the ones above. You can also use clips or twist the pantyhose between onions to separate them.

Try storing onions in pantyhose. Yes, you heard that right – pantyhose. Place one onion in the pantyhose, tie a knot above it, add another onion, and repeat until the pantyhose is full.

• This method allows the onions to breathe. Any moisture that comes into contact with them will evaporate quickly, extending their shelf life.

Use onions with thicker necks. Onions with thicker necks are the oldest and won’t last as long as younger, smaller ones.

Check the onions regularly. Take a moment every now and then to inspect your stored onions and discard any that show signs of rotting.

• Onions that have started to sprout are still edible. Simply remove the green parts before cooking.
• Avoid eating onions that have become slimy or discolored.
• Save leftover onions for planting in the spring.

Store peeled onions in the freezer. Chop the onions, spread them in a single layer on a baking sheet, and freeze. Once frozen, transfer them to a Ziploc bag or airtight container and return to the freezer. A downside of this method is the limited freezer space.

Wrap leftover onions and refrigerate them. Onions often remain unused after cooking. To preserve them for later use, wrap them in plastic wrap and store them in the vegetable drawer of your refrigerator.

• Do not store onions with potatoes. Onions will absorb moisture from the potatoes and spoil.