Here's Why You Shouldn't Freeze Food In Glass Jars

Whether you're a meal prepper, always have tons of leftovers, or just want your freezer to seem more organized, you may have found yourself contemplating using glass jars to freeze your food. But though it may seem like a convenient way to store your food, it turns out that you shouldn't really be freezing stuff in glass jars.

The problem with freezing food is that it expands in the freezing process. In a jar that's not all the way full, or in a flexible plastic container, this doesn't pose much of a problem as there's room for the food to grow. But if you're trying to save on space and have filled your glass jars all the way to the top, you could be in for an unpleasant surprise next time you open your freezer. 

That's because, when your food freezes and expands, it can push out with enough force to cause the glass jars to break (via The Kitchn). This isn't just a safety hazard when you're reaching into the freezer. It also renders your frozen food inedible, as it's too much of a safety risk to try to salvage the frozen food from the broken glass pieces, and it can also leave you with a big mess to clean up.

How to safely freeze food in glass jars

If you have your heart set on freezing food in glass jars, there are a few things to know.

For one, you should never choose jars that have a narrow opening. Those jars have a shoulder, or a point where the jar starts to become narrow. If you fill those jars up past the shoulder, they're much more likely to crack in the freezer when your food expands (via Don't Waste the Crumbs). 

Instead, choose a wide mouthed, tempered glass jar, and leave a substantial amount of room at the top of the jar — 1 to 2 inches — to allow the food room to expand in the freezer. 

You should also make sure that the food in your jars is thoroughly chilled before you put it in the freezer, to lessen the chance of thermal shock on the glass. And don't screw the jar lids on too tight — leave them a little loose, so that air can escape as the food freezes and expands. 

Follow these rules, and you can safely store food in glass jars in the freezer, no broken glass clean up needed. Or, you know, just use plastic.