Whether you grow your own white onions or you purchase them from the supermarket, your onions will stay fresh and tasty when you store them properly. Onions require careful storage to prolong their shelf life and keep them fresh and firm. Keep the temperature and humidity around your onions at the proper level and you can safely store white onions for several months.
Examine your onions before storing them to ensure there are no blemishes or bruises on any onions. Bruised onions can quickly spread decay throughout surrounding onions. Separate any onions with bruises and use these onions first without placing them into extended storage.
Place the onions with their papery outer coverings intact into the mesh bags. Fill the mesh bags approximately half-full to ensure adequate air circulation to all of the onions in the bags.
Hang the mesh bags in a location that is cool and dry. Temperatures between 50 and 60 degrees F are ideal for long-term white onion storage.
Store the white onions for two to four months in this location.