Just pulled out grandma’s vintage Corning Ware from the cupboard, ready to reheat lasagna. It looked beautiful and that made me wonder if the the heat can destroy it.
I ask everyone in my family if the heat could damage it but none knew the right answer. After doing extensive research on the corning ware microwave safety I have come with best answer to this question and more. Let’s dive in.
Is Corning Ware Microwave Safe?
Yes, most Corning Ware is microwave safe including casseroles, bakeware, and mugs. However, the Centura line of CorningWare is not microwave safe.
The Centura line of CorningWare is identifiable by its sculptured rim and plain edge without printed patterns.
Microwave-safe CorningWare products
French Square Bakeware
This set is chip- and crack-resistant, and can be used in the microwave, oven, refrigerator, freezer, and dishwasher.
French White Cookware
This set includes oval and round dishes, ramekins, and large round dishes. It’s dishwasher safe and has a non-porous surface that resists stains and odors.
Meal mugs
These BPA-free mugs are dishwasher, freezer, and microwave safe. They have a vented steam lid.
How can you tell if a ceramic dish is microwave safe?
1. Check for Labels or Symbols
The easiest way to tell if a ceramic dish is microwave-safe is to look at the bottom for a label. Many manufacturers stamp “Microwave Safe” or add a small microwave icon (usually wavy lines) to indicate it’s designed for microwave use.
If you see this, you’re good to go—no guesswork needed. If there’s no marking, you’ll need to dig a bit deeper, but this is the first and most reliable clue.
2. Inspect the Dish’s Appearance
If there’s no label, examine the ceramic dish itself. Plain, glazed ceramics without metallic decorations—like gold trim, silver accents, or shiny paint—are typically safe, since metals can spark and damage your microwave (or even start a fire).
Vintage or handmade pieces might have unsafe glazes or lead, so unless you know their history, stick to modern, undecorated ceramics to avoid surprises.
3. Test It Safely in the Microwave
When in doubt, you can test the dish to confirm it’s microwave-safe. Place the empty ceramic dish in the microwave alongside a separate cup filled with about 1 cup of water.
Run the microwave on high for 1 minute. After, touch the dish—if it’s cool or only slightly warm from the water’s heat, it’s likely safe; if it’s hot on its own, it’s absorbing microwave energy and shouldn’t be used. This simple trick helps you decide without risking damage.
What is the symbol for microwave safe?
The symbol for microwave-safe items is typically a small icon featuring three or more wavy, horizontal lines stacked vertically, resembling heat waves or microwaves.
You’ll usually find it stamped on the bottom of dishes, containers, or packaging—like ceramic plates, glassware, or plastic storage—to indicate they’re designed to withstand microwave energy without melting, cracking, or leaching harmful substances.
Some items might simply say “Microwave Safe” in text instead, especially on packaging, but the wavy-line symbol is the universal visual cue.
If you see metallic trim or no marking at all, assume it’s not safe unless tested, as metals can spark and cause trouble in the microwave.
What happens if you microwave non microwavable ceramic?
If you microwave a non-microwavable ceramic dish, several things can go wrong depending on its composition.
The dish might absorb microwave energy and overheat, causing it to crack, shatter, or even break apart due to thermal stress—especially if it’s unglazed or has air pockets from poor manufacturing.
If it has metallic paint, gold trim, or silver accents, those areas can spark, arc, or burn, potentially damaging the microwave or starting a small fire.
In some cases, harmful substances like lead from old or unsafe glazes could leach into your food as the dish heats up.
At best, your food might cook unevenly; at worst, you’re left with a ruined dish, a messed-up microwave, or a safety hazard—so it’s worth checking for that “Microwave Safe” label first!
Safe Microwave Practices with Corning Ware
When using Corning Ware in the microwave, there are key practices to follow:
1. Avoid Metal
Ensure your Corning Ware piece has no metallic parts or finishes. Metal can spark and damage your microwave. Always inspect for metal before heating.
2. Temperature Management
Despite its thermal shock resistance, avoid extreme, sudden temperature changes. For instance, do not go from the freezer directly to the microwave. Let the dish sit for a bit if it’s coming from a cold environment to prevent potential cracking.
3. Lid Safety
Most glass or plastic lids accompanying Corning Ware products are microwave safe, but check for any metal components or special instructions.
4. Correct Sizing
Use a dish size appropriate to the amount of food you’re heating. Overfilling or underfilling can lead to uneven heating or potential breakage due to thermal stress.
Corning Ware in Other Cooking Methods
a) Stovetop Use
Older models like the Blue Cornflower Corning Ware, which often came with removable handles, are designed for both range and microwave use.
However, newer stoneware versions are not recommended for stovetop cooking. Always check the base of your piece if you’re unsure.
b) Oven Safety
All Corning Ware, except for Centura, can withstand oven temperatures up to 500°F, making it perfect for baking, roasting, or broiling. This high maximum temperature for Corning Ware allows for a wide range of cooking methods.
c) Microwave Browning Dish
If you have Corning Ware’s microwave browning dish, it’s designed to crisp food in the microwave and is also oven safe, enhancing your cooking options.
How do you remove scorch marks from Corning Ware?
Removing scorch marks from Corning Ware can be done through several methods, focusing on gentle yet effective cleaning techniques:
a) Baking Soda Paste
- Mix a paste using baking soda and a little water. The consistency should be thick enough to adhere to the scorch marks.
- Apply this paste to the scorch marks on your Corning Ware.
- Let it Sit for about 30 minutes to an hour, allowing the baking soda to work on the stains.
- Scrub gently with a non-abrasive sponge or soft cloth. If the marks are stubborn, use a plastic scrubbing pad but avoid anything too harsh that could scratch the surface.
- Rinse well with warm water and dry.
b) Bar Keepers Friend
- This is a popular cleaner for removing stains and scorch marks from various kitchen surfaces, including Corning Ware.
- Sprinkle Bar Keepers Friend powder onto the wet surface where the scorch marks are.
- Scrub with a damp non-abrasive sponge or cloth in a circular motion until the marks begin to fade.
- Rinse thoroughly and dry.
c) Hydrogen Peroxide
- For lighter scorch marks, hydrogen peroxide can be effective.
- Mix equal parts of hydrogen peroxide and water.
- Dab the solution onto the scorch marks with a cloth or sponge.
- Let it Sit for a few minutes.
- Rinse and dry. This method is particularly good for light stains and might need repeating for darker marks.
d) Vinegar Soak
- Fill the scorched Corning Ware with enough white vinegar to cover the marks.
- Soak for several hours or overnight. Vinegar can help dissolve burnt-on residues.
- Scrub if necessary with a gentle scrubber after soaking.
- Rinse and dry.
Important Notes
Avoid Abrasives
Never use metal scouring pads or harsh abrasives that could damage the surface of your Corning Ware.
Test First
If you’re unsure about a method, test it on a small, inconspicuous area of the dish first to ensure it doesn’t harm the finish.
Repeat if Necessary
Some stains might require multiple treatments. Be patient and repeat the process as needed.
FAQ
Is Blue Cornflower CorningWare microwave safe?
Yes, Blue Cornflower CorningWare is microwave safe. This classic pattern, made from Pyroceram (a durable glass-ceramic material), was designed to handle microwave energy without issues. As long as it’s free of metallic trim or damage, you can confidently use it in the microwave.
Is CorningWare oven safe?
Yes, CorningWare is oven safe. Most CorningWare, especially older Pyroceram versions like Blue Cornflower and newer stoneware models, can withstand oven temperatures up to 450°F–500°F, depending on the line. Always check the bottom for specific limits, and avoid sudden temperature changes to prevent cracking.
What does Centura CorningWare look like?
Centura CorningWare looks like elegant, heavyweight dinnerware with a smooth, glossy finish, often in solid colors like white, cream, or pastel shades.
Unlike the Pyroceram CorningWare casseroles, Centura was designed as tableware—think plates, bowls, and cups—with a thicker, more refined appearance, sometimes featuring subtle patterns or gold rims.
Is Pyrex microwave safe?
Yes, Pyrex is microwave safe as long as it’s labeled as such. Modern Pyrex glassware, made from tempered borosilicate or soda-lime glass, is designed for microwave use unless it has metallic decorations or is damaged. Check for a “Microwave Safe” label or symbol to be sure.
Is Corelle microwave safe?
Yes, Corelle is microwave safe. Made from Vitrelle—a laminated, tempered glass material—it’s lightweight, durable, and handles microwave energy well. Avoid using it if it has metallic trim or cracks, but plain Corelle pieces are perfectly fine.
Is CorningWare safe to put in the microwave?
Yes, CorningWare is safe to put in the microwave. Whether it’s the vintage Pyroceram type or newer stoneware versions, CorningWare is engineered for microwave use unless it has metallic accents or specific warnings against it. Always inspect for damage first.
Is French White CorningWare microwave safe?
Yes, French White CorningWare is microwave safe. This popular stoneware line, known for its sleek, white finish, is designed to go from freezer to microwave to oven without issues. Just ensure it’s free of cracks or metallic embellishments.
Is it OK to put ceramic in the microwave?
Yes, it’s okay to put ceramic in the microwave if it’s labeled microwave safe or free of metallic elements. Unglazed or handmade ceramics might absorb energy and crack, so test unmarked pieces with the water-cup method to confirm they won’t overheat.
Is stainless steel microwave safe?
No, stainless steel is not microwave safe. Metal reflects microwave energy, causing sparks, arcs, or potential damage to the appliance. Keep stainless steel cookware or utensils out of the microwave to avoid hazards.
Can Pyrex go in the microwave?
Yes, Pyrex can go in the microwave if it’s labeled microwave safe. Most Pyrex glassware, whether borosilicate or tempered, is fine unless it has metallic trim or cracks. Always confirm with the label or a quick test.
What is CorningWare made of?
CorningWare is made of either Pyroceram (a glass-ceramic blend) for vintage pieces or durable stoneware for newer ones. Pyroceram, developed in the 1950s, resists thermal shock, while modern stoneware offers similar durability with a ceramic-based composition.
Can you heat CorningWare?
Yes, you can heat CorningWare in ovens, microwaves, or on stovetops (for Pyroceram models). It’s built for thermal versatility—Pyroceram handles extreme heat shifts, while stoneware suits standard baking. Avoid sudden temperature changes to prevent cracking.
How to use a CorningWare microwave browning dish?
To use a CorningWare microwave browning dish, preheat it empty in the microwave for 2–5 minutes (per instructions) to heat the special coating.
Add food (like meat or veggies) immediately—oil or butter optional—and cook for a few minutes per side. The hot surface sears and browns food, mimicking stovetop results.
Is 100% ceramic microwave safe?
Yes, 100% ceramic is microwave safe if it’s fully glazed, free of metal, and labeled as such. Unglazed or porous ceramics can absorb microwaves and crack, so test unmarked pieces with the water-cup method to ensure safety.
What material can you not put in a microwave?
You cannot put metals (like aluminum foil, stainless steel, or silverware), Styrofoam (unless labeled microwave safe), thin plastics (like bags), or unglazed ceramics in a microwave. These can spark, melt, release chemicals, or shatter, posing risks to you and the appliance.
What makes ceramics not microwave safe?
Ceramics aren’t microwave safe if they have metallic paint, unglazed surfaces, or hidden cracks. Metals spark, unglazed areas absorb energy and overheat, and flaws cause thermal stress—any of these can lead to breaking, sparking, or leaching into food.
Conclusion
Most Corning Ware is microwave safe, including bakeware, casserole dishes, and mugs thanks to its Pyroceram material which resists thermal shock.
However, there’s an exception – the Centura line, which is identifiable by its sculptured rim and plain edge without printed patterns, should not be used in the microwave.
Always check your piece for any metal parts or special finishes before heating, as these could cause issues. For all other Corning Ware products, you can safely use them to reheat or cook in the microwave, making them a versatile choice for kitchen tasks.