How do you know if your favorite glass bowl is oven safe? Or how about that casserole dish? If you're not sure, check for these signs:
Look for a label.
If you're buying a new bowl, it's best to check the label. If a bowl doesn't have an official label indicating that it's safe for the oven, microwave and dishwasher, it can't be counted on to withstand the heat of your oven.
Some manufacturers may include a sticker with more detailed information about their products' capabilities. These labels will say which materials the item is made from, whether or not it has lead in its glaze (which could be harmful if ingested), how many times the product can safely go through the dishwasher and what temperature range it should be heated to:
- Oven safe up to 350 degrees Fahrenheit/180 degrees Celsius
- Microwave safe up to 750 watts/10 minutes at full power
- Dishwasher safe
Check the bottom of your bowl or dish.
- If it's a casserole dish, check for a label or sticker on the bottom.
- If it's not a casserole dish, you can still check for one of these things—but you're going to have to do some digging. Look at the bottom of your bowl or dish. Do you see any writing on it? Does that writing say anything about being oven safe?
- If there's no label or sticker on the bottom, look for any brand names (Mauviel), logos (Le Creuset), model numbers (Calphalon), warning statements (All-Clad Limited Lifetime Warranty) or description statements (Calphalon Contemporary Nonstick Bakeware). A manufacturer should make clear what their product can withstand before selling them off in stores so this info should be pretty easy to find if they want people buying from them again and again!
Check the sides of your bowl or dish.
If you notice the sides of your bowl or dish are slightly bowed, it is likely oven-safe. When glass is heated in an oven, it expands and contracts with changes in temperature. A slight bow indicates that the glass has been stressed, but it hasn’t broken yet. If your bowl or dish has a clear finish on top, then it is likely oven-safe as well because heat will not cause stress to that part of your dish until well after its temperature reaches 600 degrees Fahrenheit (315 degrees Celsius).
Look for signs of stress in the glass.
When you're looking for signs of stress in the glass, look for stress cracks. Stress cracks are small hairline fractures that can form when a piece of glass cools too quickly or is unevenly heated. These may be difficult to see with the naked eye, but if you can spot them they're an indicator that there's more damage within the bowl itself.
Look also for chips and uneven or rough edges; these are other signs of damage to your bowl. If you find any damage in either place, don't use it in the oven—it's simply not worth the risk!
Drop a piece of ice into the bowl.
If you want to know if a bowl is oven safe, the easiest way to do so is by using an ice test. Put a piece of ice in your bowl and put it in the oven. If the ice melts, then your bowl is not safe for use in the oven. If it doesn't melt or even crack, then you're good to go!
It's important to remember that this isn't always reliable. There are some types of materials that can withstand high temperatures without melting and ruining their shape like ceramics or glassware (which is why they're used so often in baking). But when it comes down it, there will always be exceptions—so don't rely on this method entirely!
Use hot water in your test.
The easiest way to test a bowl's safety is to use hot water. If the oven is not too hot and you leave your bowl in for long enough, this method should be safe and effective.
First, preheat your oven to the lowest temperature possible. For example, if your oven has three settings (low/medium/high), turn it down as far as you can before turning it off once more—you should now have "warm" or "off". Next, get a pot full of lukewarm water ready (about 120 degrees F) and place it on top of the stovetop burner; do not turn on this burner yet! Once all of these preparations are complete, take out your bowl from whatever cabinet where it may be stored (or wherever else). Make sure that its rim isn't damaged or cracked anywhere before submerging it into your warm bath of H2O!
Check for factors such as clear glass, labels, and heat damage to determine if a bowl is oven safe.
- Look for labels. If a bowl has a label that says "oven safe," then it is. If you see no labels, check the bottom of the bowl to see if there are any signs of heat damage.
- Check its sides and interior for distortion or stress in the glass.
- Drop an ice cube into your oven-safe bowl to see if it cracks or shatters (this will only work with glass). If it doesn't crack, you're good!
If you still have questions about a particular bowl or dish, just give us a call. We’ll be happy to answer any questions and help you decide if it’s right for your kitchen!