5 Ways to preserve onions for pantry storage. Details on how to freeze onions, dehydrate onions, and turn onions into onion powder.
Onions are a vegetable that is often taken for granted. They are easy to get in the supermarket and are relatively inexpensive as far as produce goes. Most meals contain onions in some form, whether they are chopped, sauteed, or added as powder.
In this article, we’ll discuss the different types of onion and their uses, then how to preserve them for extended pantry storage. You might be thinking that onions already last a long time in the counter, so there is no reason to go to the trouble of preserving them.
Nothing could be farther from the truth. When you take the time to freeze, dehydrate and use onions in preserves, you will create many ways to use them year round and preserve them at their peak.
Preserving onions is certainly worth the effort!
Types of Onions
White Onions are the mildest onions, and if you are so inclined, the best for eating fresh. To take away any onion bite, slice them thinly and soak them in cold water for an hour. They will mellow and be on the sweet side, perfect for eating fresh in salads.
The instructions to preserve white onions by dehydrating, freezing, or cold storage are later in this article.
Usually called Spanish onions, these are the best onions for caramelizing. They have a sharper flavor than the other onions.
See below for ideas on how to preserve yellow onions by dehydrating, freezing, or cold storage.
Best for grilling, these provide a nice color variety and have a sharp flavor that is higher than the white onion. Red onions also have a lower glycemic index than other bulb onions.
See below for ideas to preserve red onions by dehydrating, freezing, or cold storage.
Sweet onions are technically a white onion, but they have higher sugar content than regular white onions. Each area of the USA has its own variety. Look for names like Walla Walla Sweet, Vidalia, and Maui.
Continue on to get instructions on how to preserve sweet onions by canning, freezing, and dehydrating.
Green Onions (Scallions)
Bunching onions can be planted separately from seed, but are often picked from the other onions listed above when they are at the immature stage, before bulbing starts. These are best used fresh in salad, but can also be cooked and used in eggs and oriental dishes.
View this article at The Purposeful Pantry for details on how to preserve green onions by dehydrating. You can also freeze green onions or store them in the refrigerator for up to 2 weeks.
How to Store Onion Bulbs in the Pantry
Keep onions whole for easy pantry storage. White, yellow, and red, raw onions can be kept in the regular pantry for 2 to 3 months. The key is to use a cool, dark area that is warmer than the refrigerator, but not room temperature. (somewhere between 45-55° F works best).
Create a root cellar area in your basement or in an unheated closed that is not frequently used. Use the mesh bag that the onions came in, a paper bag, or store them loosely in a basket. Do not keep them in plastic bags, which reduce airflow and will lead to premature molding.
Treat Sweet Onion Bulbs Differently
Sweet onions are fragile, bruise easily, and do not last long in storage. If you plan to use them within a week or so, you can leave them out on the counter. For extended storage look for a place in your pantry that will give you the space to keep your sweet onions cool, dry and separated.
Separate sweet onions by wrapping each onion individually in paper towels and then placing them in a brown paper bag in the refrigerator. This simple storage method will keep them for up to a month.
There are three other options to overcome this short storage time for sweet onions.
- use the canning method and turn them into onion relish (see the recipe below)
- dehydrating chopped pieces
- freeze a portion for later use
Look for sweet onions on sale during these times: [source]
- Maui: In season May through December. Smaller than other sweets.
- OSO Sweet: From Peru. Available January through March. Very high in sugars. Often found at Costco during the season.
- Texas Sweet (in the South): Two kinds: Spring Sweets and Texas 1015 Super-Sweets (the number refers to the optimal planting date, October 15). Available March through June.
- Vidalia (grown in George, available in the south): In season April through June but available into the fall.
- Walla Walla (in the Pacific NW): Available June to August.
Each area of the country has its own specialty sweet onion, but as a general rule, in most parts of the USA, sweet onions are in season from March to August.
Freezing Onions in Small Batches
If you happen to get a windfall of onions or grow your own, freezing is another option for preserving them. The good news is that it is not necessary to blanch onions before freezing them, so the process is simple.
As an alternative, you could freeze them in sheets and then break off sections as you need it for cooking projects.
Just chop the onions and place them into portion size freezer bags. I put mine into one cup portions, which makes it easy to remove a bag from the freezer and add it directly to a recipe.
Chopping tip: Are you an onion crier? I use a version of this handy chopper (Amazon). It contains the juices that cause you to cry during chopping and lets you dice a large volume of vegetables without knowing knife skills.
Another way to keep from crying is to leave the end with the roots intact. You can see how I did that in the picture with the white onions.
I also pack mine in one tablespoon portions in ice cube trays. These are great for quick sauteing recipes. Fill the cube sections with chopped onion, add a bit of filtered water to help the onions stick together and freeze. Once the cubes are hard, remove them from the tray and store in a freezer safe zip top bag or plastic tub.
Frozen onions do not have a long shelf life (6 to 8 months tops), so you might want to consider processing them for the freezer once your cold storage onions are looking a bit worn.
Another thing to consider is the texture. Once the onion is frozen, it will no longer be crisp when thawed. That means they are best used for sautéing or in soups.
This process can be used on any type of onion, including green bunching onions. To prepare, remove the papery outer coverings of the onion bulbs and compost them, or set them aside for making a vegetable broth.
Cut the remaining onion into quarter inch dices. You don’t have to be exact about it.
Cover your dehydrator trays with parchment paper or tray liners. While the pieces seem too big to fit through the holes now, they will shrink during the drying process and fall to the tray below without a liner.
Once you are done with the cutting, lay them out in single layers on your dehydrator trays.
Dehydrate at 135°F for 8 to 10 hours. Dehydrating times are only estimates. Your time will vary by the amount of humidity in your house and by how much you load the trays with food. Giving the trays more room for air circulation will speed up the process.
NOTE: Dehydrating onions is smelly business and everyone in your house will definitely know what you are doing. If you have grumbly family members and a garage or other protected area, you might consider doing your drying outdoors.
You’ll know your onion dices are dehydrated when they are very crisp and will click on the countertop when dropped. No amount of moisture will be seen when you pinch a piece open.
Store the dehydrated onion pieces canning jars with tight-fitting lids, or place them in FoodSaver bags. Whichever method you choose for storage, make sure the pieces are completely dry. Store them in a cool, dark place – your pantry shelves are perfect.
How to Make Onion Powder at Home
Once your onions are dehydrated, run them through a blender, coffee grinder or food processor and turn it all into powder. If your blender does not powder all the pieces, use a wire mesh strainer to sift out the larger pieces and run them through again. I use this coffee grinder (Amazon) and it never gets the whole batch into powder, so I leave some of the onion as dried minced onions and use it in recipes that do not need powder.
Spicy Pickled Sweet Onion Relish
[yield 3.5 cups]
This onion relish is tasty on hamburgers and hotdogs. You can increase the amount of sugar (up to one cup) if you like a sweeter relish. Try mixing various kinds of bulbing onion for a different flavor.
- 10 cups chopped sweet onions (about 7-8 medium-sized onions)
- 2 1/4 cups white vinegar
- 1/2 cup sugar
- 2 tablespoons celery seed
- 2 tablespoons kosher salt
- 1 teaspoon crushed red pepper
- Combine all ingredients in a non-reactive pan and bring to a boil.
- Reduce heat and simmer for 10 min.
- Ladle the relish into clean hot half-pint jars with 1/2 in head-space.
- Wipe the rims, cap the jars, and loosely seal.
- Process sweet and spicy onion relish in a water bath canner for 10 minutes.
Let the jars sit for two weeks before using; this gives the onion time to age and mellow.
Use one of these five methods for preserving onions. You’ll be glad you have some on hand in different forms – from fresh, to dried, to frozen. There’s a use for all of them in your kitchen pantry.