When we’ve got food to freeze, many of us will reach for a Tupperware box or a resealable bag. But as we all try to use less plastic, is glass a safe alternative for storing food in the freezer? Perhaps more importantly – can you pop a bottle of beer or wine in the freezer?
Can You Put Glass in the Freezer?
If you follow a few simple rules, it is perfectly safe to put glass in the freezer. Opt for tempered or freezer-safe glass, make sure you allow room in the container for any liquids to expand, and ensure you allow any cooked foods to cool fully before freezing.
What’s the Best Way to Freeze Food in Glass Containers?
Firstly, choose tempered or freezer-safe glass. Several brands now make freezer-safe storage containers. You can also use canning jars like you get pasta sauce and jam in, so start saving empty jars instead of sending them for recycling.
Opt for jars with straight sides, as jars with shoulders or conical shapes allow less room for liquids to expand as they freeze.
When putting homemade food and drink into glass containers, ensure you allow plenty of room for any liquid component to expand as it freezes.
Between one and two inches is a good benchmark (or roughly 20% of the container).
Another helpful tip is to place the containers in the freezer upright and only put the lids on loosely until the contents are frozen, then tighten the lids.
If freezing freshly cooked food, allow it to cool fully before placing it in the glass storage container. If you are batch cooking, you can place the hot food directly into the storage containers while still hot, but allow it to cool fully before placing it in the freezer.
How Do You Defrost Food in Glass Containers?
Food that has been frozen in glass containers needs to be defrosted slowly. Start the process in the fridge, then take it out and leave it to defrost at room temperature for the remaining few hours.
If you want to speed this up, you could place the glass container in a bowl of cold water and keep replacing the water every so often.
Never try to cook food frozen in a glass container until thoroughly defrosted.
If you place it straight into a microwave or oven, it is likely to shatter. It is also dangerous to try sitting it in warm or hot water for the same reason.
Can You Freeze Shop-Bought Drinks in Glass Bottles?
If you’ve got a bottle of beer or wine, or one of the high-end soft drinks that comes in a glass bottle, and you want to cool it down quickly, you might be tempted to pop it in the freezer.
However, there won’t be enough space in the bottle to allow the liquid to expand when it freezes, so if you leave it there too long, it’s likely to explode!
Freezing Beer
If you decide to pop a beer in the freezer, 15 minutes will likely get it nice and chilled. Any longer than this and it will start to go slushy and can affect the taste.
Freezing Wine
With wine, the best option is a wine bucket, but if you don’t have one or you forgot to make any ice, you can pop the bottle in the freezer for up to half an hour.
Any longer than this is likely to affect the aroma and taste.
Freezing Soft Drinks
If you want to freeze a bottle of soft drink, the best option is to pour out a small drink first to allow room for the drink left in the bottle to expand as it freezes.
After about 20 minutes it should be nicely chilled. Don’t leave it too long as it is likely to set solid.
Can You Put Pyrex in the Freezer?
Yes. Pyrex is made using borosilicate glass, which is specifically designed to have high thermal shock resistance.
This means it is resistant to extreme temperatures, from -40°C to 300°C. It can also be placed directly in the oven from the freezer, as long as the oven temperature is no higher than 200°C.
Technically, it could also be put directly in the freezer from the oven because the glass could handle the thermal shock.
However, we wouldn’t recommend it as it would raise the internal temperature of the freezer, which wouldn’t do the rest of the items in your freezer, or the freezer itself, any good.
Do keep an eye out for damage. While a chipped Pyrex dish is safe to keep using, it does weaken the glass, so the thermal shock resistance can no longer be guaranteed.
Is It Dangerous to Freeze Glass?
If you don’t follow the suggestions above, it can be dangerous to freeze glass.
If you try to freeze the wrong kind of glass, or a glass container that is still warm, or if you don’t allow room for any liquids to expand, the container could explode, spreading splinters of glass throughout your freezer and potentially damaging the appliance too.
What Are the Advantages of Using Glass Containers to Store Food?
Like plastic storage containers, glass is durable, reusable, and microwave and dishwasher-safe, as well as being tolerant to high and low temperatures.
You may not realise this, but many plastic containers are not recyclable. Even some labelled as recyclable cannot be processed by some recycling plants.
Glass, on the other hand, is 100% recyclable.
Another benefit is that it doesn’t absorb liquids, so it doesn’t retain smells, odours, or the risk of bacteria in the same way plastic does.
Recent studies suggest that harmful toxins can leach out of plastic and into food, particularly when the containers are heated. These toxins have been linked to health problems such as metabolic disorders, developmental issues and various illnesses (more on this in The Guardian here).
Related FAQs
Do you still have concerns about using glass in the freezer? Then these might help:
Yes, as long as you ensure it is at room temperature before putting it in the freezer, ensure you allow room inside for any liquids to expand and don’t use a jar with a chip or crack.
Generally, you can freeze glass jars of sauce without any issues. Some brands of sauce, however, will have a warning on the label to state that the container is not safe for the freezer.
