Generally, onions are good for about two weeks after purchase.
However, freezing them can extend their life for up to 6 to 9 months.
To freeze, cut into half-inch thick rings, chop in a food processor or grate the onion and store in a freezer bag.
These methods will help you use all of your purchased onion instead of throwing out any that have gone bad.
Onions that have been frozen show no difference in taste or smell before being used.
However, when they thaw from being frozen, the resulting texture is closer to water than when they were fresh.
This will not affect their usability in most recipes when cooked properly with other ingredients but might be noticeable alone as a side dish if eaten cold.
(Related: The best frozen onion rings for air fryer)
In addition to extending the life of onions, freezing is a great way to preserve fresh garlic.
Garlic can stay frozen for about six months before it begins to show signs of degradation.
While freezing onion and garlic does not affect their usability in all recipes, there are some types of food that they should not be used in.
This includes any dish that needs thinly sliced or chopped pieces as the texture will change and become watery when defrosted.
These include salads and some salsas as well as dishes where they will be eaten cold such as some summer soups.
Onion and garlic can both be kept frozen for about 6-9 months without causing health problems if done properly.
If you notice changes in color or texture before 9 months, the food should be thrown out.
Freezing onions and garlic can greatly extend their usable life but may not be suitable for some types of cooking.
Is it OK to freeze raw onions?
Onions are high in water content, so freezing them can cause them to “lose flavor and texture” a bit.
If you have onions that are overly ripe or wilted, however, you can freeze them for up to 6 months without it having any negative impact on the taste.
Can you freeze cooked onions?
Cooked onions also contain a lot of water, but this doesn’t mean they should never be frozen.
Like their raw counterparts, cooked onions will lose some of their flavors if they are frozen immediately after cooking.
If you want to freeze your leftover fried or caramelized onions, make sure you let them cool completely before storing them in an airtight container in your freezer.
It is best to use cooked onion in freezer recipes within three months in order to avoid this flavor loss.
Is it OK to freeze onions that have started to sprout?
It’s perfectly safe to freeze onions if they have started sprouting or are overly ripe, but there will be a decline in taste and texture once the vegetable thaw.
Like most root vegetables, when onions start to sprout they lose some of their water content, which means that any freezer burn is likely to affect the flavor more once the vegetables are thawed.
Before you put your onions in the freezer, make sure they are completely dry for best results when thawing them at a later date.
Does freezing affect the onion health benefits?
Freezing onions can affect the antioxidant activity of this vegetable, but it does not reduce the health benefits.
The antioxidant properties in onions are mostly located in their outer layers.
So if you shuffle through your freezer looking for a frozen onion with the most unthawed skin you’ll be getting more of these antioxidants than if you cook with one that has had some parts exposed to thawing already.
Is it safe to store onions in a plastic bag?
Onions should never be stored together with other fruits and vegetables in the same refrigerator compartment.
This is because they release a gas called propanethial S-oxide that can damage other food types, changing their flavor or making them spoil faster than usual.
If you buy onions lose instead of pre-packaged, it is best to store them in a breathable container such as a mesh bag.
Onions can be stored in plastic bags once they have been peeled or cut, but this should only be done if you are going to use the vegetables soon.
What can I do with too many onions?
The most common way to preserve fresh vegetables is by blanching, which involves placing them in boiling water for a few minutes and then transferring them to an ice bath.
To freeze whole onions, blanch the entire onion before freezing it.
You can also chop or slice your onion before freezing it so that you can measure out however much you need at a time.
Put the prepped onion in heavy-duty freezer bags and press all of the air out before sealing it.
Label the bags with the date and contents, and use your frozen onions within 6 months.
Further reading: