Storage / Preserving

Storage

When the stems turn brown and brittle, cut off the roots entirely, and the stems 1-2 inches (2.5-5 cm) above the bulb. I usually gently rub the bulb in my hands to remove the dirt and a couple layers of outside skin. Once properly cured, onions store for a long time. 

Onions with bruises or blemishes should be used first, as well as onions whose skins came off and are showing some or all of the flesh. 

Onions store best in a cool, dry, dark airy space, inside nylon mesh bags, brown paper bags, wicker or wire baskets, milk crates, or burlap sacks. The recommended temperature for long-term storage is 35°F to 40°F (1.6-4.4°C) or 50–70°F (10-21°C) with 60–70% humidity. Onions may sprout if stored between 40–50°F (4.4-10°C). 

Properly cured yellow potato onion bulbs store well, lasting up to 12-24 months in the right conditions. It is my understanding that red, Green Mountain and white potato onions do not store as well as yellow, which is why some gardeners fall-plant those varieties.

I store mine in metal baskets in the basement in which the temperature year-round is 70°F (24°C) and my onions keep until spring, at which time they sometimes break dormancy due to it being room temperature. If they do break dormancy I remove the skins, dice them and freeze them for eating purposes.

Preserving

All options are available for preserving potato onions: canning, pickling, freezing, dehydrating, fermenting, and storing as discussed above.