Glass is a great way to safely store food, whether it’s in the fridge, the pantry, or even the freezer. It’s perfectly safe and extremely easy to freeze food in glass containers, but there are a couple of things you should keep in mind to prevent freezer burn and glass breakage.
You can safely freeze food in glass containers if you set your freezer’s temperature between zero and five-degrees Fahrenheit, cool down your food before freezing, and freeze it in small batches. Ensure you use Pyrex or tempered glass containers and leave two inches of space when freezing liquids.
The most important goal when freezing food is that the food should taste as flavorful and fresh as possible after you reheat it. Let’s look at how you can safely freeze food in containers, which glass types are freezer-safe, and whether you should freeze hot food to keep leftovers without worrying about freezer burn or glass breakage.
Can You Freeze Food in Glass Containers?
You can safely freeze food in a glass container, but there are a couple of steps you should take to prevent freezer burn and avoid breaking the glass.
Set Your Freezer to the Correct Temperature
It’s best to set the temperature of your freezer somewhere between zero and five degrees Fahrenheit. This will help freeze the food much more quickly and keep it fresh.
If you’ve set your freezer at a higher temperature, the food will freeze slower, forming bigger ice crystals and causing freezer burn.
Cool Down Your Food Before Freezing
This might seem counter-productive to the previous step of freezing your food as quickly as possible. But, if you directly put hot food in your freezer, it’ll cause more moisture to escape, resulting in freezer burn.
The hot container will warm up all the other food in the freezer, increasing the chances of those items getting freezer burn. Also, remember a glass container subjected to quick temperature changes is more likely to break or crack.
Use Small Containers
Small batches of food in small containers will freeze much faster than large portions in big containers. And the quicker the food freezes, the fresher and more flavorful it’ll taste after you thaw and reheat it.
Keep Your Freezer Full
Your freezer works most efficiently when it’s full. This is because all the items in your freezer maintain frozen temperatures, so it doesn’t have to work as hard. However, ensure you don’t stuff your freezer full, preventing proper air circulation.
Add an Extra Layer of Protection
If the food in your glass container is exposed to air, it will freezer-burn. Luckily, you can easily prevent this by putting your food in a plastic bag or wrapping it before placing it in the container for an additional layer of protection. Make sure you remove all excess air from the bag as well.
Which Types of Glass are Freezer Safe?
Keep in mind that every glass container isn’t freezer safe. For this reason, it’s always better to choose a glass container with ‘Microwave, Oven, and Freezer Safe’ stamped on the bottom. However, there are a few other glass types that are freezer safe:
Tempered glass is usually made from either soda and lime silicate or borosilicate. The glassware (on Amazon) may be labeled with this information, or it might just say ‘tempered glass.’ This material keeps your food fresh and protected and ensures that the container remains in one piece when you place it in the freezer.
Pyrex containers (on Amazon) are designed to be freezer and oven-safe. However, a Pyrex dish should never be exposed to quick temperature changes. It’ll probably crack or break like all other glass containers.
So, when you cook a meal, let it cool before placing your Pyrex container in your freezer. Similarly, when you pull the dish out of your freezer, wait for its temperature to go down before placing it in your microwave or oven.
Which Foods Can You Safely Freeze in Glass?
- Biscuits: After cooling the biscuits, freeze them in a wide-mouth jar.
- Citrus zest: Reduce food waste by freezing citrus zest in a glass container or jar.
- Beans: Allow cooked dried beans to cool down before placing them in a glass container or mason jar without or with a liquid.
- Fruits and vegetables: Lay out fruits and vegetables flat on a tray first, freeze them, and then move them to a glass container or jar to place back into the freezer.
- Vegetable scraps and peels: Freeze them in a glass container or jar and then use them to make some flavorful broth.
- Broth, sauces, and soups: Whenever you freeze any liquid, make sure you leave a space of at least 3cm from the top, no matter the consistency.
- Leftovers: Divide all your leftovers into small portions for quick and easy midweek meals.
- Baby food: Make lots of baby food in one go and freeze it all in glass baby food containers for healthy, easy meals every day.
Can You Freeze Liquids in a Glass Jar?
You can safely freeze liquids in a freezer-safe glass jar (on Amazon), but only if you leave sufficient space at the top for liquid expansion. It’s best to leave an inch or two of space from the top in straight-sided jars, but if you’re using curved jars, then make sure you leave the same amount of space from the point it curves.
Should You Freeze Hot Food?
You shouldn’t freeze hot food because the rapid temperature changes might crack or break your glass container. So, thoroughly cool the food before placing it in the freezer.
Instead of leaving the glass container out and letting it cool on the counter, you can also place it in the refrigerator until it’s cool and then place it in the freezer.
How to Prevent Glass from Breaking in the Freezer
You can easily prevent glass from breaking in the freezer by leaving a bit of ‘headspace.’ Since frozen food usually expands, leaving some space will help prevent pressure from building up and breaking the glass. For safety purposes, leaving one to two inches of space from the top is best to allow enough room for expansion.
It’s also important to remember that each glass type handles thermal stress differently, so it’s better to use tempered glass or borosilicate glass containers when freezing and heating food and drinks.
Remember that rapid temperature changes can break glass containers, so it’s important to thaw them first in the refrigerator before heating them back again. Don’t try to speed up the thawing time by placing the container in water or microwaving it, as this can also cause it to break.
While you can reuse your old glass jars, keep in mind that they might be more susceptible to cracks when frozen. Thin-necked bottles are also at a higher risk of cracking, so avoid using them.