Wondering how to preserve onions now that the harvest is coming in? Some crops like onions are all ready at once and can feel overwhelming to process everything at once. Thankfully there are three simple methods for preserving onions no matter whether you grow long-day or short-day onions.
Cure and Cellar
This is by far the simplest and least time-consuming storage method for onions. After harvesting your onions, you’ll need to find a warm spot that is out of direct sunlight (75-80F is ideal) and has good airflow. For us, we hang onions and garlic from the rafters on our back porch. Or you can set them out in an uncrowded single layer and then wait about 2-3 weeks until the stems are dry, brown, and withered. Then they are ready to be stored in a cool, dry, dark place. Most storage onion varieties last 8-10 months in storage.
Unfortunately, there’s a catch. If you live in the lower latitudes of the South like we do, we’re unable to grow the types of onions that keep well in a root cellar! Long-day onions last between 8-10 months, but those of us with short-day options are stuck with maybe 3 months of storage if we’re lucky. Definitely not long enough to make it to the next harvest! (What’s short-day vs. long-day?) Thankfully there are other methods when growing long-day onions isn’t possible in your region.
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Freeze Diced or Sliced
This is my favorite method for preserving onions as it also helps me save time cooking later. Since short-day onions have about a 3-4 month shelf-life after curing, I simply chop up a few onions here and there over a few weeks and freeze them either diced or as slivers. While this does take time upfront, it just exchanges the time I would have spent in the kitchen when cooking a meal that calls for an onion. So the time trade-off is totally worth it for me.
I like using a silicone muffin tin to freeze the onions in approximately small onion-sized balls for quickly adding to soups, stews, and other recipes that call for diced onions. Another great way to freeze them is in Souper Cubes and have your onions frozen in pre-measured portions for your recipes. For slivers or diced onions you want to freeze loose, simply allow them to initially freeze on a baking pan or tray before tossing them into a Ziploc bag or other container for storing in the freezer.
Dehydrated Onions
Lastly, when we have enough frozen diced onions on hand, I’ll run them through the food processor into finer pieces and pop them into our dehydrator to dehydrate. After they are dry, you can store them as is for dried minced onions or you can make your own onion powder. To make our own powdered spices, we use an old electric coffee grinder we found at a thrift shop to make a fine powder. If you want to go the extra mile to store the dehydrated onions and keep them from clumping, you can use a vacuum sealer for mason jars to extend shelf life.
Preserving Onions Strategy
Now that you know how to preserve onions three ways, it’s time to talk about practical strategies to fit this around your busy schedule! As I hinted at above, we use all three methods to preserve onions for our kitchen pantry.
The week of the onion harvest, we hang all of them up to cure. Even though short-day onions don’t last as long when cured, it does buy me time to work the other two preservation methods. When I have a few extra minutes here and there over the next couple of months post-harvest, I’ll chop up a pan or muffin tin worth of onions while watching a fun Youtube video or send a few through the food processor and pop them in our dehydrator real quick. Easy peasy with minimal food preservation stress!
P.S. Zero Waste
Don’t forget that the scraps are usable as well! The little bits of root ends and the more leathery layers that are usually peeled off prior to chopping can be stashed into a freezer bag and used whenever you are making broth.
Happy growing and preserving this summer!
