How to Can Onions

By Charlotte King

Onions are usually very common in every kitchen. They are used as a basis for many dishes and add a distinct flavor to your food. Not only that, but onions also provide several health benefits thanks to their anti-inflammatory properties and the high amount of anti-oxidants, and those are some of the reasons why you should learn about the canning onions process to be able to preserve them and use them later.

One might argue that onions are one of those ingredients that cannot miss from any kitchen. Because of the “indispensability” of this “bulb”, many people tend to purchase a lot of onions at once. However, the risk of buying big volumes of food is that it might go bad. Onions might get soft or start sprouting, which will make them not usable for cooking anymore. How can we avoid that from happening?

Well, one solution will be canning onions. This article will be your ultimate guide on how to can onions, so keep reading to find out everything to know about this storing process and extend your onions’ shelf-life in a simple and rather cheap way.

Why Should You Can Onions?


You might be wondering what is all about canning onions, right? The thing is canned onions are great to be used as a condiment just out of the can, in burgers, or added sauces while you’re cooking your dishes.

The procedure is quite simple and while allowing you to store your onions for up to six or seven months.

Remember however that preserving food that is not very acid (therefore with high PH), such as onions, requires pressure cooking to kill harmful bacteria that cannot be digested by the human body.

One of these bacteria is botulism, which might have severe consequences if consumed. Unfortunately, by simply boiling the food on the stovetop, you’ll not be saved from the risk, thus it is essential that you can them under pressure.

That said, canning onions is pretty simple.

The necessary ingredients are onions, salt, and a pressure canner, so you don’t need to plan before deciding to can them.

For medium-sized onions, the following procedure is recommended:

  1. Prepare the glass jars where you want to store your onions, make sure both the jars and lids are maintained hot.
  2. Wash the onions and peel the skin off. If you have to deal with large onions, cut them into thick chunks half-inch wide.
  3. Place the peeled onions in a pot and cover with water, bring the water to boil at medium-high heat and let them boil for 5 minutes, or until they gain a translucent color.
  4. After the onions are translucent in color, remove them from the pot, (but keep the cooking liquid) and place them inside your warm glass jars.
  5. Add half a teaspoon of salt to each jar If the size of your jars is “quarts” add 1 teaspoon; for pints, half of a teaspoon is enough.
  6. Pour the cooking liquid (which should be still hot) inside the jar, covering the onions and living a 1-inch head space from the lid.
  7. Remove any air bubble using a spoon and add more liquid if necessary, so that the 1-inch head space is maintained.
  8. Properly seal your jars.
  9. Now it comes to the most important step: process your jars under a pressure canner.
  10. If using a dial-gauge pressure canner below 2,000 feet, set the pressure to 11 pounds for 40 minutes. If using a weighted gauge canner, set the pressure to 10 pounds for elevations below 1,000 feet or 15 pounds for elevations above 1,000 feet for 40 minutes.
  11. Once the pressure returns to 0 pounds, wait 10 more minutes and carefully open the lid of the pressure canner.
  12. Test the seals, if you find some lids that are not properly sealed, store those jars in the fridge and consume them within 2 weeks.

Here it is: now you have safely canned your onions and can enjoy them in a variety of meals, to add a specific and tasty flavor to your meals!

Tips on Storing and Preserving Onions

So we’ve just seen how to can onions properly, but what about storing them? Are there any other ways I can extend the onion’s shelf life if I do not have a pressure canner at home?

The good news is yes, you can. Here are some tips to better store and preserve your onions in different ways.

How to Choose the Best Onions

Even if storing onions properly is important to prolong their shelf-life, selecting the right onions is important. It would be a shame to buy old onions and all the effort spent in preserving them correctly will be vain. So let’s go over how we can choose the best onions when buying them.

As a rule of thumb, go for the onions that present dry and papery skin. Choose those onions whose outer papery layer is without spots or moisture. When picking them, onions should be firm and not ripe. Those that have begun to sprout will rot quickly, so they should be avoided.

A good selection of dry red onions

Store Onions in Dry, Cool, Dark and Well-Ventilated Areas

Once you have bought the best onions, it is time to think about how to store them

Onions tend to become mushy after a while, due to their moisture-absorbing characterizing. This means, they act as “sponges” and absorb humidity very quickly and easily. With high-enough temperatures, they quickly start rotting or sprouting. It is so disappointing when you start cooking, reaching out for onion, and realize they went bad.

To prevent that from happening, try to store your onions somewhere dark, well-ventilated, and cool. It might be a cellar, basement, pantry, or garage. To ensure proper air ventilation, place them in an open wooden basket or a mesh bag. Avoid storing them inside plastic bags as they accelerate the rotting process since they do not allow proper ventilation.

Do Not Store Whole and Unpeeled Onions in the Fridge

Yes, we’ve said a cool place, but storing onion inside the fridge exposes them to too much cold and humidity. So do not store your onions in the fridge!

However, if you’ve cut or peeled your onions, then you should place them inside your fridge inside an airtight container. By doing so, your onions will last between 10 days to 2 weeks.

What If I Want to Preserve Cooked Onions?

You can easily store cooked onions in the fridge, but they won’t last long, usually up to five days. Place them inside an airtight container without leaving your cooked onions outside for too long to avoid them from growing harmful bacteria (do you remember the botulism bacteria we talked about before?).

If you wish to store them for longer, consider freezing your cooked onions, they will last for as long as three months.

Can I Freeze Onions?

Freezing whole, raw onions is not recommended since it spoils the taste and the texture. However, if you’re often in a rush, you might be happy to know that you can freeze chopped onions, which turns out to be very handy for quickly sauteing recipes. Simply chop your onions, and place them inside an empty and clean ice-cube tray. Add some water to help the onions stick together and freeze. Once the “onion cubes” are frozen, place them in a resealable plastic bag inside your freezer. They will last for up to seven months

Frozen chopped onions are handy, however, they won’t have the same texture as they have when fresh. But when you add them in soups or sauteing recipes, where the texture is not as important. they do a great job.

How to Make Dried Onions

Alternatively, another method to preserve onions is to dry them. Dried onions are delicious, not only they add the classic and tasty “onion flavor” to your dishes, but they also add that special crunchiness that can make your meals a bit more creative and “special”.

Even if it sounds complicated, the procedure of drying onions is pretty simple and does not necessarily require a dehydrator. Mind you that if you choose to dry onions in a “normal oven”, it can be done, but it will be a bit time-consuming. Furthermore, dry onions is a rather “smelly business”. If you have enough time and don’t mind the onion smell lingering over your home for a while, go ahead!

To dry your onions, simply wash them and remove the outer “paper shell”. Cut off tops and root ends from your onions and slice them into cubes. Try to have them cut in an even thickness.

If you have a dehydrator, place your onions inside the machine at 130F to 140 for 3 to 9 hours. Alternatively, place your chopped onions on a baking tray lined with baking paper and set them at the lowest temperature. Then, let them inside the oven until they are dry and check them periodically. It might take a while, but you’ll have amazing, golden-dried onions in the end!

Once the onions are dried, store them in glass jars in a cool and dry place.

Overall, onions are an important ingredient in the kitchen, a versatile “must-have” that is important to store properly so that they can last in good condition for the most extended amount of time. They come in different types and sizes.

We’ve provided you with an ultimate guide about some methods to preserve onions properly and add different flavors to your meals: enjoy!

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