Glass items can go in the oven, as long as they are oven-safe.
But if you’ve ever seen a glass mixing bowl shatter, you might be wary of putting glass in the oven. Bakeware sets made of glass will use special tempered or heat resistant glass that makes them safe for high heat.
Learn how to determine if the glass can safely go in the oven and other recommendations to follow when using glass cookware.
Determining if The Glass Is Oven-Safe
Look at Your Container
Most ordinary glass bakeware will have an indicator on the product to show it is oven safe. Try flipping the pan over and check the bottom for a symbol or writing that indicates it is oven safe.
Check The Manufacturer’s Guide or Packaging
Not all glassware will have a symbol or label directly on the product. But, this doesn’t mean that the glass is not oven safe. If you know the manufacturer, look up the user guide or check the product packaging.
The manufacturer will usually clearly indicate if the glass dishes are oven-safe or not oven-safe. If it is not clearly indicated, it’s best to assume it is not safe for baking.
Inspect the Material
But what if you’ve already thrown away the packaging? In this case, you need to inspect the type of glass that is used.
Glass containers are made from either tempered glass, borosilicate or soda-lime glass. Tempered glass and borosilicate are oven-safe, but soda-lime glass isn’t. So how do you know which type of glass you have on hand?
Recognize the Type of Glass
It takes a skilled eye to recognize heat resistant glassware. But by picking out a few key traits, you can determine whether the glass is tempered, borosilicate or soda-lime.
Tempered glass is most easily recognized by its edges. It will normally have smooth edges due to the processing it goes through.
Types of glass other than tempered will usually have scuffed or ridged edges. So, if you feel any sort of roughness, it is likely not tempered glass.
The best way to check is to run your fingers along the edges to feel for any roughness.
Another feature of tempered glass is some sort of etched or sandblasted label. You can usually find this on the corner of the glass, and this will indicate it is tempered.
The best way to recognize borosilicate glass is by immersing it in mineral oil. The glass will disappear (not really, but in appearance) if it is borosilicate.
Borosilicate glass should always appear clear. If there’s any color or tint, it is likely not borosilicate.
Borosilicate glass is mainly used in chemistry lab equipment, cookware and even aquarium heaters. Those trendy glass thermoses you see everywhere are usually made with borosilicate glass too.
Soda-lime glass is perhaps the easiest to recognize, due to its blueish-green hue. Soda-lime glass is the most common type of glass. Many food jars, bottles and household windows are made with soda-lime glass.
If you cannot recognize the type of glass, the safest option is to not put it in the oven – if the wrong type of glass is put in the oven, the glass breaks.
Using Glass in the Oven Safely
- Do not expose glass to sudden temperature changes. This will cause thermal shock and can make the glass break or crack.
That means do not add cold water to a hot glass pan. And alternatively, do not put a hot glass pan into a cold area like a freezer. Avoid using wet cloths to handle hot glass as this could also cause it to react.
- Allow glass to cool completely after baking. It’s best to have the glass cool on a cooling rack or a dry cloth. Do not set hot glass on a wet cloth or cold surface. Do not refrigerate or wash the glass directly after it has come out of the oven.
- Avoid direct flames. Do not use glass baking dishes over top of a broiler, grill or stovetop. When a direct flame hits one area, it can weaken the glass and cause it to crack. Stick to using glass in the oven, where it can heat up evenly.
- Do not use chipped or cracked glass. Once glass has cracked, it is very likely to shatter if it gets hot. If your glass is showing signs of weakening, it’s best to replace it.
- Do not set the oven above 450°F. This is advised when you are putting glassware from the freezer into the preheated oven. The sudden hot oven temperatures will likely crack or shatter the glass. Always check the maximum temperature of your glass dish before using it in the oven.
- Add water to the bottom. This is important when cooking frozen foods that seep liquids. Adding liquid beforehand will prevent the cold liquids inside from directly hitting the hot pan as your food cooks.
Glass Oven-Safe Maximal Temperature
The maximum temperature oven safe glass can withstand will entirely depend on the brand. Some are designed to withstand higher temperatures than others.
Here are the maximum cooking temperatures from the most popular heat resistant oven safe glass manufacturers:
- Amazon Basics: up to 1076°F
- Pyrex: up to 572°F
- Anchor Hocking: up to 425°F
- OXO: up to 450°F
- JoyJolt: up to 1040°F
- GAC: up to 350°F
But going from the freezer to the oven, you have to make sure the heat isn’t too high.
For example, Pyrex glass can resist thermal shock up to 220°F (or 428°F). If your freezer is -4°F (-20°C), you can’t have the oven higher than 390°F (200°C). Doing so will likely result in your glass container shattering or cracking.
The last thing you want is glass exploding in your oven, so make sure you know the maximum cooking temperature. This information is almost always found on the product packaging, or the manufacturer website or user guide.