You can use the links below to skip through this article if you need help with how to go about freezing onions, how to defrost them or whether it’s actually worth doing in the first place:
How to Freeze Onions
There are so many options you have to pick from when freezing onions. You can even freeze them roasted with other vegetables for a quick and easy to use side dish. Below we have covered three common methods for freezing onions:
How to Freeze Chopped Onions
For this method of freezing onions, we’re going to consider how you would normally use them when cooking. You probably use them chopped up, diced or sliced. Well, that’s exactly how you’re going to freeze them. This will make them even more convenient to use.
- Prepare Onions
Peel your onion, removing the root and then cut in half. Place your onions halves in a food processor and whizz it up until it is finely chopped. Don’t worry, you can also do this by hand, but it is somewhat more time-consuming – especially if you’re trying to bulk freeze your onions.
- Portion into Bags
Scoop portions of your finely diced onion into individual bags and label them.
Place in the freezer in a single layer. This prevents them from sticking together when freezing. Once the bags are frozen, you can, of course, stack them.
It’s also worth noting that you need to use sturdy, thick bags for onions. Onions smell, and you don’t want your freezer and the rest of the contents to take on an onion odour. Onion scented ice cubes in your gin and tonic are not going to be pleasant!
You can also blanch the onion before freezing by placing in boiling water for 3 minutes then transfer them to a bowl of ice-cold water. This is said to help maintain nutrients better than raw onions.
The other great thing you can do is freeze onions in a ready prepared soffritto. This makes up the base of many pasta sauces and Mediterranean dishes. If you want to learn how to create your own frozen, soffritto mix, then click here.
How to Freeze Onion Puree
The good news is that chopped onions aren’t the only approach to take when freezing onions. You can also make an onion puree. This is great as part of the base to curries and Asian inspired dishes.
Just peel and chop the onions. You only need to chop them up roughly.
Place them in the blender with a splash of water and hold down the button until you get a thick, smooth puree. You can always add other spices, seasoning and garlic at this stage. You may want to add a little more water if it too thick.
- Portion into Ice Cubes
Transfer the puree to ice cube trays and freeze. This should only take a few hours.
- Final Freeze
When completely frozen, move the iced onion cubes to a plastic bag and leave them in the freezer. You can grab a cube as and when you need them.
How to Freeze Whole Onions
There’s nothing to stop you from freezing onions whole. They won’t be bad for you. They won’t fail to freeze. The problem with freezing them whole is that they’re not an efficient use of space or time. If you decide you need a whole onion, then you’ll need to give it plenty of time to thaw as you’ll find it near-impossible to dice when frozen.
You’re far better off taking the time to prepare your onion into diced pieces or rings and then freezing it.
4 Tips for Freezing Onions
Now you know how to freeze onions in a variety of ways, we’ve got our 4 top tips which we strongly recommend following when freezing them to have the best results:
- Avoid Freezing Whole Onions – There are no advantages to freezing onions whole. Yes, you’ll have saved the onion from going in the bin, but you’ll have to wait for an entire onion to thaw and then do all your prep work.
- Prep Beforehand – Preparing your onions beforehand is a huge time saver. This means top, tailing, peeling and dicing before you freeze onions so you can grab a handful as and when you need them.
- Shake After 30 Minutes – Once the onions have been in the freezer for 30 minutes, give them a quick shake in the bag. This can help prevent them from sticking together but without the need to flash freeze.
- Don’t Thaw – There’s no need to thaw them before using. Place your frozen onion pieces into a pan over a low heat to thaw gently and then cook as you normally would.
How Long Can You Freeze Onions?
Frozen onions will stay good for 3 to 6 months in the freezer. However, we recommend using them within about 2 months because they can start to lose their flavour after that. Having reached the 6 months limit, the onions may no longer have much flavour left, defeating the point of having them ready to go in the freezer.
The best way to freeze your onions would be to place small portions at a time in bags (for example, a supply for 3 or 4 weeks), so they maintain their fresh flavour.
You Can Freeze Onions for up to 2 Months
How Do You Defrost Onions?
There’s no need to thaw the onions before placing them in the pan. Just add them directly to whatever dish you’re preparing. You can put them briefly under running water to remove any layer of ice if you feel it’s necessary.
When cooking the onions from frozen, make sure you start with low heat to thaw them out gently. If you use high heat, you’ll find that you burn the outside of the onions before you get to thawing out the middle.
Can you Refreeze Onions?
It’s certainly possible to refreeze onions, and it’s safe to do so… But we’d recommend against doing so. Onions are packed full of flavour, and a lot of that flavour is contained within the onion’s liquid content. When you thaw out an onion, you draw out some of the moisture and some of the flavour.
If you freeze, defrost, refreeze and defrost, you’ll remove a lot of the moisture and therefore a lot of the delicious onion flavour.
Do Onions Freeze Well?
Frozen onions are only suitable for cooking. We don’t recommend using them in raw dishes such as salads because they become soggy and lose their texture. There’s nothing like a fresh onion if you want to use onion in salads or other raw dishes.
If you’re cooking dinner and want to use your frozen onion, it’s good to know that if you consume your frozen onions within the first 6 weeks after having frozen them, there isn’t much difference in taste and/or nutrient levels. As time goes by, they start losing their flavour. The closer you get to the six months mark, the flatter the onion’s taste will be.
If you’ve still got questions about freezing onions or onions in general, then these may help:
How Do You Freeze Onions Without the Smell?
There isn’t a secret or hidden trick when it comes to freezing onions without stinking out your freezer. It’s as simple as using extra-thick, freezer-friendly bags. The cheaper sandwich bags are fine for some items but will let odours and liquids seep out. Instead, invest in some purpose-made, thick bags which you can use to store your onions.
If you want to go further, then you can place this bag into a container to reduce the risk of the onion smell spreading throughout the contents of your freezer.
Can You Freeze Onions, Carrots and Celery Together?
You certainly can. This is known as a soffritto or mirepoix as is great to have in the freezer as it makes up the base on many dishes – especially pasta sauces. We’ve written about how to freeze soffritto on our guide to freezing carrots. Check that out as a way to freeze onions, carrots and celery together.
Can You Freeze Onions and Garlic Together?
You can. But we wouldn’t. There will be times where you only want to add garlic to your dish. There will be other times when you only need onions. That’s why we would actually advise freezing onion and garlic apart and then combining them as and when you need them.