Have you been wondering, "Can I freeze food in glass jars?" If so, the answer is yes BUT not all glass jars are suitable.

Glass jars can be really handy for freezing soups, stocks, broths, sauces, curds, freezer jams, pesto and pate in. Follow the tips below to avoid breakages in your freezer.

How to freeze food in glass jars

Glass jars have the risk of cracking as the food freezes, so it is important to be careful of the following:

• only use straight sided jars that you know to be freezer safe - straight sided means straight from the bottom to the top with no shoulder or curvature
• leave enough room for expansion (approx. 3 cm)
• allow the jar and contents to cool in the fridge before transferring to the freezer
• if using a plastic lid that simply pushes on then you can press that in place before freezing
• if using a screw on lid then place the lid only lightly on the jar and screw on once the food has fully frozen
• be careful with stacking the jars in your freezer so they aren't cracked by heavy items falling on them

What is a straight-sided jar?

Straight-sided means straight from top to bottom. Sometimes a jar will taper outwards from the bottom to the top, this is ok to use. If, however, the jars gets narrower towards the top, this is unsuitable as when the food freezers it will expand through that narrowing area putting stress on the glass.

If the jar has a shoulder (curves in towards the neck of the jar), this is also unsuitable for the same reason mentioned above. Food expands as it freezes so there needs to be space for it to expand upwards without any narrowing or restriction.

The image above is a useful representation of what jars are and are NOT suitable for freezing food in. 

Jar brands I recommended for freezing food in

I love using Le Parfait Super Terrine and Le Parfait Familia Wiss Terrine jars for freezing food in. The Super Terrine option is my preference as they have glass lids so no metal lids that tend to corrode over time when in the freezer.

Another option that works well are Weck Mold Jars. These are best paired with their plastic Keep Fresh Lids.

Some Ball mason jars are suitable too, just check that they are straight from bottom to top (the 8oz quilted crystal jelly jars, wide mouth pints and wide mouth pint and a half jars are suitable).