The Real Reason You Shouldn't Freeze Food In Glass Jars
Meal prepping is a way of life for many of us, and a part of it is finding the right containers to store food in various stages of preparation. There are so many different ways to build an arsenal of meal-prepping containers, from saving and cleaning certain takeout boxes and mason jars to buying a matching set of plastic or glass containers with air-tight covers. Whichever way you choose, it's important to know which types of containers to use in each situation. For instance, did you know you shouldn't freeze food in regular glass mason jars? If you did, you could end up with your entire glass jar collection breaking on you (via Real Simple).
As you might remember from high school science, sudden temperature changes can cause glass to shatter — particularly if it's not tempered or specifically designed for freezing. What's more, as it freezes, your food expands, which is fine in flexible containers like Tupperware. However, if that same food is packed tightly in an inflexible glass jar, there's nowhere for it to go when it expands. So, as the food freezes, pressure builds inside the glass and that pressure can be strong enough to shatter your jar (via The Kitchn).
Smarter ways to freeze your food
Since this is the kind of mess no one wants to clean up, you can play it safe by sticking with strong zip-top bags and flexible plastic containers when freezing food. Of course, this doesn't mean you have to stop reusing glass jars entirely; they can come in handy for short-term storage in the fridge.
If, however, you still would prefer to freeze food in glass instead of plastic, there is definitely a safer option than using jars for the task. The New York Times recommends the Pyrex 18-piece simply food storage set. The tempered glass is easier to clean than most plastic, won't absorb food smells, and claims to be freezer and microwave safe. However, Pyrex does warn against taking the storage dishes from the freezer and placing them directly into a hot oven, as the drastic temperature change can cause them to shatter. Basically, you want to avoid ever heating or cooling glass too quickly (via Epicurious). Take it slowly, and you're sure to avoid a big mess and an even bigger headache.