It’s May in Georgia and that means Vidalia onion season. While these are famous for their sweet flavor, there are numerous varieties and colors of onions. Onions are used in many unique, flavorful condiments – relishes, salsas, pickles, and jams to name some of the most common. Sometimes we just need to preserve onions themselves.
I’m often asked why our University of Georgia So Easy to Preserve book does not have the option of freezing diced onions. Well, I can’t explain why it was never in the early editions and we just haven’t been able to issue a whole new edition since the 6th edition in 2014. This is one of the drawbacks of a large book that you don’t revise or reproduce for one issue at a time. We have had this additional option on our Freezing Onions page at the National Center for Home Food Preservation for the past few years:
Peeled, washed onions can be diced or chopped (1/4-1/2 inch pieces suggested) and frozen without blanching. If you have room in your freezer, it is best to spread the pieces out on a clean cookie/baking sheet in a single layer. When they are frozen (hardened), promptly remove from the tray and package air-tight in freezer bags or containers while they are still hard. This keeps pieces separated in their freezer packaging enough that you will be able to remove only as much as you want at a time. If they are all put into the bag or container at room temperature, they will freeze into one large mass and not as separate pieces. If you are going to remove part of the amount frozen at a time versus using the whole amount, it works best to use freezer bags, so you can push the air out when you re-seal the remaining frozen pieces. In a hard container, the air left in the box/jar as you keep removing some is not good for quality and can cause freezer burn (drying out of the food).
The National Center for Home Food Preservation also has this webpage with more ideas and tips for preserving onions: https://nchfp.uga.edu/tips/summer/onions.html. At the end of it, there are links to our Canning Relishes factsheet with several that emphasize onions and others that contain some onion content.