If you’ve cooked for many people, chances are that you ran out of cooking vessels and needed to rely on less conventional cookware, like glass dishes.
You can only put “oven-safe” glass in the oven. Many types of glass will break in the oven or the decorations may ignite. Refer to the care and use instructions on each piece of glassware before exposing it to direct heat.
It can be hard to determine what is safe to put into the oven and what isn’t. So, read on for our handy guide.
Oven Safe vs. Non-Oven Safe Glass
There are significant differences between oven and non-oven safe glass. So, you need to be careful. If you use a dish for something it isn’t intended for, you could end up cleaning up a big mess.
Here are the features of oven-safe glass:
- Handles the high temperatures in an oven.
- Is tempered and reinforced.
- Is typically plain without decorations that could ignite or explode during use.
Oven-Safe Glass
Oven-safe glass is specifically tempered and prepared for safe oven use. It is designed to hold up under high cooking temperatures without breaking.
Most oven-safe glass is clear without any non-glass decorations. It is also typically resistant to hot and cold temperatures and won’t shatter when moved from one environment to the other. However, it can break if not handled properly.
Most oven-safe glass is made of a specific type of glass called borosilicate. This type of glass is made with silica and boron trioxide to create a durable piece of glassware.
The mixture is incredibly resistant to high and low temperatures and will not break, making it very popular in laboratories and professional kitchens.
Pyrex glassware is a recognizable example of borosilicate glassware. It was first developed in 1915 after Bessie Littleton (the wife of an engineer) experimented with some glassware her husband borrowed from the lab. Her success convinced her husband’s company to start selling one of the first borosilicate cookware brands.
Non-Oven Safe Glass
It is always safe to assume that your glassware is not oven safe, unless a label says otherwise. Untempered glass is usually thinner and not nearly as durable. It also can’t handle more than moderate temperatures.
On top of that, if it has been painted or has non-glass decorative objects attached, it is most likely not oven safe. These decorations could melt, burn, and contaminate your food.
It’s better to use this glassware for decorative plating at the end of the cooking process. This is especially true if you have glassware with metal accents. Metal accents can become explosive under high temperatures and especially in the microwave.
Carefully check the interior for any non-glass attachments. Also, look for cracks, chips, or any other damage. If you see any, do not use the glassware.
What if There Are No Use Instructions?
If there is no care and use instructions in the box, there are a couple of ways you can figure out what type of glass you have. These are pretty simple to find and will keep you and your food safe.
Check the Bottom of the Glass
Some glassware has a stamped label explaining what you can or can’t do with it.
This label is usually on the bottom and is typically imprinted into the glass during the production process. This is the quickest way to identify if the glassware is oven-safe.
Sometimes, there are not words but symbols. If there is a symbol shaped like an oven, it should be oven safe. Other symbols can be there too, like a snowflake for freezer-safe or a heating element saying you can use it on the stovetop.
Your stovetop or microwave oven may also have signs to indicate what type of glassware you can use with them. However, these labels are less common. If you don’t recognize any of the labels, you should look it up before you proceed with cooking.
Compare Temperatures
If you already have a piece of oven-safe glassware, you can test the two. This approach is not as safe, and you should always err on the side of caution.
Preheat your oven to a lower temperature. Ideally, keep it under 300 °F (148 °C) so that the mystery glassware doesn’t shatter if it is not oven-safe. Put it into the oven on a baking tray alongside with a piece of glassware you know is oven safe.
Do not test the temperature with your hand. Instead, use an infrared thermometer like the Etekcity Infrared Thermometer (available on Amazon.com). This is a great tool to check temperatures without getting hurt and it can read temperatures up to 716 °F (380 °C).
An infrared thermometer is a great kitchen tool, especially when testing how hot something is without hurting yourself. You can use this to check the temperature of your oven, grill, or even what you cooked.
How To Stop Glass From Breaking in the Oven
Glassware can be very expensive, so you want to take care of it. You need to take steps while using your glass cookware to make sure it lasts a long time.
Here are a few things you can do to stop your glass from breaking:
- Do not change temperatures dramatically.
- Do not seal glass containers.
- Do not cook at very high temperatures.
- Use tempered glass.
All of these will make sure your glassware doesn’t break in the oven.
1. Do Not Change Temperatures Dramatically
You should not move your glassware from very high to very low temperatures or vice versa.
This can cause all kinds of issues, including cracks and even shattering if the temperature change is large enough. This can even happen to borosilicate or tempered glass. So you shouldn’t completely expose your glassware to those kinds of temperatures.
Once you see cracks on your glassware, stop using it and safely dispose of it. Cracked glassware is susceptible to future cracking, shattering, and runs the risk of getting shards in your food.
2. Do Not Seal Glass Containers Going in the Oven
Do not seal glass containers you put in an oven. This is very important and will prevent most broken glass in the oven.
If the vessel is completely sealed, it will almost certainly shatter at high temperatures. That is because pressure builds up in the container as the food inside cooks. This pressure will stress the glass, and with nowhere to go, the pressure will start pushing at the glass.
So, you will lose the glass cookware and anyone nearby could be hurt. Pressure explosions can throw shards at very high speeds.
3. Do Not Cook at Very High Temperatures
Cooking at high temperatures is something that most oven-safe glass can handle. However, most non-oven-safe glass will start to break over 300 °F (148 °C).
Be mindful of how hot the oven is and what you are cooking. Glassware can get hotter than other cookware, so you may also need to adjust your cooking times or add more liquid to prevent burning.
If you are using dark glass, lower the temperature. Darker cookware tends to hold onto heat better, especially at the top and bottom.
This is great if you want to get something brown on both the bottom and the top, but sometimes you want something that will cook evenly. In those cases, you should reach for a clear pan.
If you are cooking with a clear pan when the recipe calls for a dark pan, raise the temperature by 25 °F (3-4 °C). This will replicate the effect of using a dark pan.
4. Use Oven-Safe Glassware
The best way to prevent your glass from shattering in an oven is only to use oven-safe glassware.
As explained above, there is no better choice for safe cooking. Oven-safe glass has been specifically designed and tested at high temperatures to withstand cracks. These types of dishes often have many decades of design behind them and are proven to be safe.
Interestingly, oven-safe cookware is also commonly great for freezing things. It can usually hold up to the freezing process and won’t shatter as it gets colder. However, make sure you don’t overfill it because the water in your food expands when it freezes and may break the container.
Check the bottom of your glass to see if there is a freezer-safe notation. If you see a small snowflake logo, it should be good to store in your freezer. When in doubt, you could always call the manufacturer or look on their website for more information.
However, you should be careful that you do not move the glass from the very cold temperatures into very hot ones without any thawing. Do not put the glass container from the freezer right into a hot oven. This could make the entire glass shatter and then you have a big mess to clean up.
What To Do if Your Glass Breaks in the Oven
Glass can break no matter the precautions you take. If the situation arises, you can take a few steps to take care of the mess and make your life easier.
Do Not Panic
Broken glass is bound to happen, so do not beat yourself up over it. Unless the glass was an heirloom, you can pick up the pieces and go on your way.
Besides, being nervous makes it easier to make a mistake and get hurt in the process. You need to keep a level head and take a moment to relax before handling sharp glass.
Wait for the Oven To Cool Down
The next step is to switch off your oven and wait for it to cool down. Shut everything off and wait until it is cool enough to work with.
If possible, remove any food that may be left in the oven. You do not want it to stick to the oven or burn as the oven cools down.
Also, be careful not to accidentally burn yourself while trying to clean up the glass.
Remove the Glass Chunks
Carefully remove the largest chunks and set them aside. Preferably, store them in a cut-proof container, like a bucket or box.
Be careful not to cut yourself. The best thing to do is use a cut glove to protect yourself from injury.
An excellent cut glove is the NoCry cut-resistant gloves on Amazon. These are designed for use in the kitchen whenever you need to handle something sharp.
Clean Up the Small Shards
Cleaning up all the tiniest shards is an arduous task. However, there are some great ways you can clean them up with little to no effort.
An interesting way is to use a slice of bread or potato. These two items will help clean up the tiny little bits and get them out of hard-to-reach areas.
If you do not want to waste the food, you could also use a damp sponge or a wad of paper towels. These will also pick up the small bits.
Make sure you properly dispose of whatever you used to clean it up. Never use the item you cleaned up with for other things. You do not want to get glass in something else.
Properly Dispose of the Glass
The best thing to do with broken glass is to put it in a trash container. If you want an extra layer of protection, keep the glass in another bag or sealed container before you put it in the trash.
You cannot just put the broken glass into your recycling bin since a waste disposal worker could get hurt handling it. Some recycling facilities will take broken glass, but that policy changes from location to location.
Hi all! I’m Cora Benson, and I’ve been blogging about food, recipes and things that happen in my kitchen since 2019.