What You Should Know Before Freezing Food In Mason Jars

Using mason jars as food storage containers is an unsurprisingly trendy method since they're cheap, versatile, and look aesthetically pleasing on the shelf. Whether you're using them to store flour or using the mason jar bands to bake muffins — there's no arguing that they're a practical item to have on hand. Short term food storage in mason jars is a no brainer, but using your mason jar to freeze food long term might actually be a food storage mistake. Whether you can use your jars in the freezer or not depends on a few factors: the jar shape, the amount of space you leave inside, and temperature changes.

Mason jars that have tapered or straight sides are freezer friendly, but shouldered jars should steer clear from your freezer. Shouldered jars get narrower towards the top, which can turn into a weak spot if liquids like soup are frozen inside. Since liquids expand when frozen, there's a risk of your jar shattering or cracking due to the pressure.

Because of food expanding in the freezer, it's also important for you to leave adequate head space, which is the gap between your food and the jar lid. The amount of head space you need depends on what you're freezing, but a good rule of thumb for solid foods is leaving just over an inch of space. Liquids will need ½ inch for a pint jar, 1 inch for a quart and 1 ½ inches for any bigger sized jars.

Lastly, you want to make sure that there's no sudden temperature changes once you remove your mason jar from the freezer. This can cause the jar to shatter or crack, as it will unevenly expand at a rapid rate. Even if it's a small crack, it's safest to throw out both the food and the jar. To avoid this, let your mason jar thaw in the fridge so that the temperature difference is less significant. As long as you stick to these golden rules, mason jars will make storing food in the freezer easier than ever.