Canning, Freezing & More Preserving / Recipes

How to Safely Freeze Liquids in Mason Jars

How to safely freeze liquids in mason jars

It’s that time of the year when our freezers are probably seeing a lot of action as sauces, soups, stock, and all kinds of seasonal bounties start making their way from the garden to the kitchen to — eventually — this winter’s dinner table.

A lack of space in my own freezer means I’ve skipped my old standby of freezing whole cherry tomatoes in favor of tomato purees that are ready to spice up for homemade marinara sauce, soup, and ketchup.

(Here’s my favorite recipe for homemade tomato sauce, no blanching, peeling, or seeding required!)

And that brings up a question I’m often asked: What’s the most ideal way to store these liquids in the freezer?

For years I used the flat-pack baggie method: fill a few zip-top freezer bags with liquid, squeeze all the excess air out, then lay them flat and stack them in the freezer.

While that tested-and-true method is pretty handy in the kitchen, these days I find myself reaching for my mason jars more and more.

They’re easy to fill, easy to thaw, free of leaks, and useful for storing leftover liquids in the fridge (without the need to decant into a separate container).

Related: 8 Canning Tips and Tricks for Modern-Day Home Canning

If you’re trying to avoid excessive use of plastic in the home, glass mason jars are a great reusable option that you likely already have around. You can freeze liquids in mason jars and store them for several months in the freezer.

But! If you aren’t careful, the glass may crack or shatter as the liquids solidify.

So here’s a quick tip for making sure that doesn’t happen…

Use only straight-sided mason jars and fill them to the freeze-fill line.

Freeze-fill line on regular-mouth pint mason jar

On Ball and Kerr branded jars (which are made by the same mason jar manufacturer), the freeze-fill line is a thin line found just below the threads, about an inch from the rim.

Some (though not all) of their jars even have “For Freezing — Fill Here” embossed on the line.

Freeze-fill line on regular-mouth half-pint mason jar

The purpose of the freeze-fill line is to indicate the maximum amount of liquid you can safely store in your jar without risking a cracked jar when the contents freeze and expand.

Freeze-fill line on wide-mouth half-pint mason jar
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Jars that are best suited for freezing liquids include:

Happen to notice a common feature among these jars? They all have straight sides.

Jars that have shoulders, such as regular- and wide-mouth quarts, are not suitable for freezing liquids unless you fill them to no more than 1 inch BELOW the shoulders.

This isn’t the most efficient use of space, since only 2 1/2 cups of liquid will fit — but in a pinch, it’ll work.

I’ve successfully frozen liquids in quart jars by making sure I leave plenty of headspace (about 3 inches) for the liquids to expand upward.

Fill quart jars to no more than 1 inch below the shoulders

If you aren’t comfortable with this, but like the convenience of jars and need to store more than jelly jars allow, you can also try plastic freezer jars. (These are great, and recent versions have better fitting lids than the previous Ball-branded versions.)

Here are a few things to keep in mind to reduce the risk of breakage with glass mason jars:

  • Glass can crack under thermal shock. Always cool liquids to room temperature before filling your jars.
  • Place your jars inside a cardboard box or other shatter-proof container before putting them in the freezer. This keeps other items from knocking into them, especially if you use a chest freezer. (These pretty storage boxes are perfectly sized for pint jars, and I especially like this genius JarBox protector — it’s kind of like an egg carton for jars.)
  • Don’t expose your frozen jars to sudden heat. Defrost them in the fridge, or out on the counter at room temperature.

What are some of your favorite foods to stash in the freezer?

Mason Jar Sources

Ball 4-Ounce Quilted Crystal Jelly Jars | Ball 8-Ounce Quilted Crystal Jelly Jars | Kerr 12-Ounce Glass Jelly Jars | Ball Regular-Mouth Half-Pint Jars | Ball Wide-Mouth Pint Jars | Ball Wide-Mouth Pint-and-a-Half Jars | Ball Plastic Freezer Jars | Victorio Kitchen Products Pint Jar Storage Boxes | JarBox Protector for Canning Jars

This post updated from an article that originally appeared on July 24, 2017.

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24 Comments

  • newbie
    May 8, 2023 at 3:12 pm

    great & detailed info Linda! especially about the hidden freeze line, straight sides, and initially freezing without the lids on larger containers.
    having to make food ahead for my ailing dad. whatever isnt finished soon enough gets put into the freezer.
    just switched to smaller canning jars because the similarly sized pyrex & anchor hocking werent doing as well; although the lid is secure before going into the freezer, it’s loose after it freezes.

    Reply
  • Kathy
    September 15, 2022 at 7:09 pm

    The link for JarBox Protectors goes to a product that does not look like an egg carton for jars.

    Reply
    • Ruth
      October 5, 2022 at 11:37 am

      I saw that too.

      Reply
  • Cheri
    August 22, 2022 at 9:27 am

    Yay…happy to hear that I don’t have to use plastic! Thanks for the tips!

    Reply
  • Renee cunningham
    May 8, 2022 at 1:01 pm

    I bought organic juices in glass jars the shelflife they say to use within two days after opening and refrigerating.
    Can you freeze the juice after opening a large bottle so you do not have to consume it within two days?

    Reply
    • Linda Ly
      May 20, 2022 at 8:45 pm

      Yes you can freeze juices after opening, but make sure the liquid level is below the shoulders of the jar as recommended in this article.

      Reply
  • Sarah
    March 13, 2022 at 5:03 pm

    Have you ever frozen milk in a mason jar?

    Reply
    • Linda Ly
      March 13, 2022 at 7:10 pm

      I haven’t because we just drink it fresh at home, but milk freezes just like any other liquid.

      Reply
  • Adenike
    December 7, 2021 at 10:08 am

    I really appreciate this idea of freezing mason jars. I didn’t know That I must not fill to the shoulder, I even filled to the rim. Since I cracked one bottle, I’ve been afraid to do it again. What a big help you are. Thanks a lot. I’ll try again the fight way.

    Reply
  • Melonie Snyder
    July 7, 2021 at 9:47 am

    This article was so helpful. Thank you

    Reply
  • Teena
    March 30, 2021 at 11:04 am

    This probably a dumb question, but I make my sauce with meatballs & sausages. Is it ok to add these to the jars as well? Or if i end up using freezer bags, is it ok to add these too?

    Reply
    • LorBen
      August 25, 2021 at 6:28 am

      I would not can your sauce with meat. It would extend the processing time with a pressure cooker. That extra time of processing might not give you the best quality tomato sauce. Freezing it with meat is okay though. If it was me, I would add my meat the day I cook the sauce. You could process your meat separately, which would create more space in your freezer.

      Reply
  • RJ
    March 3, 2021 at 9:46 am

    Alan, I like your idea. After cracking a jar this week, I was also thinking about freezing in “layers”. In other words, fill one-third full, freeze and then repeat twice (still leaving the proper head room). I’ll let you all know how that turns out.

    Reply
  • Pamela Moore
    December 12, 2020 at 8:07 am

    I am planning to freeze some apple pie filling in glass mason jars and all of the info in this articles and these comments are invaluable. A friend of mine, who freezes a lot in jars, told me another tip. Freeze without the lids and when the product is frozen, put the lids on and replace in the freezer. She says this has worked for her all of her life.

    Reply
    • Michael
      March 4, 2021 at 8:20 pm

      Voila! thanks for that tip. Pun intended.
      Oh and the Jarboxes are super high priced on Amazon. Will look for another source.

      Reply
      • Shelly
        April 8, 2021 at 7:57 am

        Target or Walmart

        Reply
  • StormyLuv
    August 23, 2020 at 2:49 am

    Will this process work for Apple Butter?

    Reply
    • Linda from Garden Betty
      September 5, 2020 at 4:03 am

      Yes, I recommend taking the same precautions for freezing apple butter. (Though most of what I’ve seen/made is usually thick enough to not expand as much as liquid.)

      Reply
  • Maura
    November 20, 2019 at 1:34 pm

    I froze in wide mouth and narrow mouth jars (quarts usually, occasionally half gallons and pints) for years with only a cracked jar or two. I left good head room, capped them and FROZE THEM ON THEIR SIDE to avoid the break at the shoulder problem. Then seemingly out of the blue, I lost a few in a row which bummed me out.

    My googling led me to someone telling me that if the top of the jar wasn’t absolutely dry and clean when I lidded my jars that that could cause a crack when the contents froze.

    That’s when I switched to 24 oz wide mouths for freezing. I fill to fill line, freeze without lids, then lid them the next day. I haven’t lost another jar in over five years.

    The 24s are a more efficient use of space because you get as much or more product in them than you do in a quart jar you can’t fill to the fill line

    Aside– I just visited friends who have soup frozen in jars…to the top! I could see one of the poor widemouths was cracked so I took it out, set it in a pan to thaw so I could show my friend and share my useful tip about the likely cause being something on the rim. To my horror, she decanted the soup into another jar!!! Not completely calmly, I explained that you can’t know for sure that there isn’t a glass shard in that. She argued. I said …I hope you don’t kill yourself or any of our loved ones including me!

    Reply
    • Linda from Garden Betty
      November 22, 2019 at 2:54 am

      Oh yikes, I hope your friend realizes how sketchy that is!

      I also agree that those pint-and-a-half jars are great for freezing!

      Reply
    • Carla
      September 25, 2022 at 9:50 am

      I will admit to doing that too but I always scrape the frozen soup on the outside especially where the cracks were and then rinse it. I am assuming the cracks happen at the frozen stage??????

      Reply
    • JJ
      December 22, 2022 at 11:59 am

      Thank you Maura!
      “That’s when I switched to 24 oz wide mouths for freezing. I fill to fill line, freeze without lids, then lid them the next day. I haven’t lost another jar in over five years.”
      Freezing with or without lids is what I needed to know.

      JJ

      Reply
  • Dom
    October 12, 2017 at 7:37 pm

    Thanks, that was great. Awesome that a fill line is built in.

    Reply
  • Alan
    October 6, 2017 at 9:15 am

    Just bought my first jars, wanted to freeze homemade broth to make soup. Wanted to use quart size and understand about not filling to much because of breakage, and how quart size not good use because you can’t fill it up full with liquid, so my thought is to fill as you say, I think it was about 2/3 rds full, freeze, and then fill with veggies after liquid frozen. Just thinking outside the box, hope I don’t have any issues with freezing any jars.

    Reply

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