Can you freeze food in glass jars?

I get this question so often, I wanted to put the answer in its own post.

In short:

Yes! You can freeze food in glass jars!

I have done it somewhere around 8935 times, and it’s been just fine unless I’ve dropped the glass jar. Which is a me problem, not a freezing-food-in-glass-jars problem.

 

I know we are all rather terrified of causing glass breakage…that’s a messy problem, and it also results in food waste because WHO is going to try to eat food that might have glass shards in it?

(Not me! I might hate food waste, but I hate chewing on glass even more.)

But you really do not need to be terrified. It is not as if glass magically explodes once it hits the cold air.

What makes jars break in the freezer? A lack of headspace

Freezer breakage typically happens when you do not leave sufficient space for the food to expand.

If you’re freezing something like nuts, seeds, or flour, then of course this is not a problem; those things don’t expand much at all when they’re frozen.

But if your jar contents are water-based, then they’re definitely going to expand.

And if you have a tight lid on a full jar, when the contents expand too far, they will indeed push right through the glass.

If the water-based contents can’t go up, they will go out.

Isn’t that kind of crazy to think about? That these tiny water molecules become so strong when they freeze, that they can actually break glass?

It kind of reminds me of how weeds can push through asphalt or concrete.

Anyway!

To fix this….

Leave sufficient headspace!

(Headspace = the amount of room between the food and the lid of the jar.)

I err on the side of caution when it comes to this, and if you are new to freezing food, you probably should too! It’s always better to leave a little extra room while you’re learning how much food expands during the freezer process.

If you are really nervous, you can always freeze the jars without the lids and then screw the lids on later. That will ensure the food has plenty of room to expand upward.

Do you need to use wide-mouth jars?

Ball does make wide-mouth jars that are labeled specifically for freezing. I think the shape of them is a little better because there’s no neck and the food can seamlessly expand upward and slightly outward.

BUT.

I have frozen food plenty of times in standard Ball jars, and it’s been fine.

Do you need specific lids for freezing in glass jars?

Nope! You can use (and reuse) the usual metal lids and metal bands.

Since those are prone to rust, I’ve also used Ball’s plastic screw-on lids (mine are the older white style, but this is their current style.)

A lot of off-brand lids are available as well, but since I haven’t tried them, I can’t vouch for how long-lasting they are. I can tell you my plastic Ball lids have lasted for years.

Also, you know how the grated Parmesan lids work on standard-mouth jars? I’ve frozen those plenty of times too and they’ve been fine.

Can you freeze glass tomato sauce jars from the store?

This is probably the most common food-freezing question I get and my answer is yes.

These jars are not quite as heavy-duty as actual canning jars, so you might want to be slightly more careful with them.

But I’ve frozen food in them plenty of times and it’s been fine as long as I leave sufficient headspace.

This is super duper handy if you have only used half a jar of tomato sauce and you know you won’t use the rest in time. Just throw the whole thing in the freezer!

As an added benefit, you will never wonder, “Hmm, what is this mysterious container of red frozen stuff?” because the jar’s original label will tell you!

Once you’ve used the tomato sauce, you can save the jar and the lid for future use; I use mine to freeze food and I also sometimes use them when I make yogurt.

Also, some tomato sauce jar lids screw right onto standard Mason jars so those are super handy to keep around!

How do you thaw food in glass jars?

I just take the jars out of the freezer and let them thaw on my countertop or in the fridge.

I do know that glass does not like sudden temperature changes, so you wouldn’t want to put a frozen jar into a hot oven or something!

And I wouldn’t be brave enough to run a frozen jar under hot water.

But going from the freezer to room temperature has never posed a problem for me.

What kind of foods do you freeze in glass jars?

I typically freeze:

• homemade broth
• homemade applesauce
• homemade freezer jam
• soups
• extra spaghetti sauce

Relatedly, my “try it and see how it goes” philosophy is helpful for freezing foods. If you wonder whether a food item can be frozen, or how it will be when it thaws, try it with a small test sample!

Then you’ll know for the future.

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If you have any other freezing-in-glass questions (or cautionary tales), do share.