Can I freeze food in glass jars?

Is it safe to freeze glass jars?

A lot of people are worried to freeze food in glass jars because they think the glass will break when frozen. Glass breaks because of stress, it is rigid and solid, so when pressure is applied it tends to crack. Although it’s rigid, glass actually shrinks a little when it’s cooled and expands a little when heated.

Choosing the right jar to freeze

Wide neck jars are perfect for freezing, this is because the wide neck allows room for easy movement and important when storing liquids. Tapered jars such as Mason and Weck jars are great because when you’re defrosting the jars the food slides out easily due to the shape.

Step by step how to freeze in a glass jar

Once you’ve chosen a suitable jar, fill it with whatever you want to freeze, following these rules:

• -Fill to the widest point of the jar and leave a space at the top to allow the contents to expand
• -Cool the food completely before putting the jar in the freezer
• -Place the jar in the freezer, with the lid off or ajar
• -Once the contents have completely frozen, screw the lid on tightly

How do you defrost the glass jar?

Once you are ready to take the jar out of the freezer you will of course need to defrost it, heating frozen glass will make it crack so make sure to NOT do this! You will need to take the jar out of the freezer and set aside for a few hours, or alternatively leave in the fridge overnight to defrost. But if your low on time and need to defrost something quickly, you can take the jar out of the freezer and pour cold water into the jar, this separates the jar and the content and makes it easy to get the food out of the jar.

Top Tip…

NEVER heat up frozen glass jars as it will cause the glass to crack!