Can you put glass in the freezer? Yes, provided you use this type of glass container

Storing your leftovers in glass containers is often a more environmentally friendly and less smelly alternative to plastic. But can you put glass in the freezer?

Freezing food is a well-known kitchen storage hack to make your food last longer. But what you use to put your food inside the freezer is very important. OXO Silicone bags and plastic food containers are both freezer-safe solutions, but as it turns out, some glass containers are also well-suited to below-freezing temperatures.

If you’re in a bid to move away from plastic this year, there are some glass containers you can safely store in the freezer. We asked the experts and this is everything you need.

Can you put glass in the freezer?

‘Glass can be stored in your freezer but it's advisable to take some precautions as it can shatter when exposed to extreme temperature changes or is an unsuitable glass for your freezer,’ explains Sarah Heaps, refrigeration expert at AO.com.

Not all glass is suitable for freezing conditions and risks shattering - spoiling your food and giving you an added cleaning job in the process.

‘You should only place a glass container in the freezer if it is labelled as freezer-safe. Borosilicate glass containers are well suited to putting in the freezer, as they are more resistant to thermal shock compared to other kinds of glass. This is because borosilicate glass does not have air pockets that contract with temperature changes,’ says Liam Spencer, owner of Northallerton Glass.

Pyrex glass is an example of Borosilicate glass and can be stored in your freezer. It is best to avoid any thin or decorative glass as this has the highest risk of cracking.

‘This glass is specially designed to withstand any temperature changes, but you should still try to avoid moving this directly from your freezer to a hot oven and always ensure it is at room temperature before you pop it into your freezer,’ says Sarah.

How to prevent glass shattering in the freezer

'To minimise the risk of glass cracking in your freezer, try to leave space for any container expansion. Liquids expand as they freeze so leave an inch gap to allow for this. Also, try to let your hot foods cool to room temperature before you place them in your freezer. Similarly, avoid overfilling your freezer as pressure or contact can again lead to cracking,’ recommends Sarah.

Food or liquids that haven’t completely cooled risk thermal shock when the glass is placed inside the freezer which causes cracking. It also increases the risk of bacteria growth.

‘Use a container that has a silicone lined lid, as this will provide an airtight seal to keep food fresh and help to prevent freezer burn,’ Liam also recommends.

‘Avoid freezing liquids in jars that have a narrow neck and use wide-necked jars or a jar with sides that taper outwards instead. Wider jars will have more space to allow for any expansion of the liquid as it freezes.’

When purchasing glass storage containers, ensure they are labelled as freezer-safe if you want to use them to store leftovers - this way, you will avoid pulling any broken glass out of your freezer.