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Is CorningWare Microwave Safe? (Safety Tips & What to Avoid)


CorningWare is a durable bakeware brand that people have used for many years. Many of its products are lightweight and have intricate designs, which can cause many to worry if they are microwave safe. The short answer is yes. You can microwave most CorningWare, but keep reading as we show you how to determine if your items are safe and provide you with several microwave safety tips.

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What Is CorningWare?

CorningWare is one of the most popular baking wares in the United States. It was developed in 1953 when a scientist accidentally discovered its main ingredient, a ceramic glass that could handle thermal shock up to 840 degrees Fahrenheit, making it perfect for cookware. It often has a blue cornflower on the side, but many other designs exist.

Is CorningWare Microwave Safe?

Yes. CorningWare can withstand temperatures over 400 degrees Fahrenheit without cracking or breaking, even if you drop it, so it is safe to use in a microwave. A microwave works by heating water molecules, and this prevents the temperature from getting any hotter than 212 degrees Fahrenheit, which is the boiling point of water.

Woman's Hands Closing Microwave Oven Door And Preparing Food At Home
Image Credit: Andrey_Popov, Shutterstock

Is CorningWare Food Safe?

Yes. Pyroceram, the ceramic glass in CorningWare is non-toxic, so you don’t need to worry about it leeching harmful chemicals, like phthalates and styrene, into your food as you microwave it. The interior is also non-porous, so it won’t absorb stains or odors that can taint your food. However, some experts point out that the exterior of vintage items might contain a small amount of lead.

Is CorningWare Microwave Durable?

Yes. The ceramic glass in CorningWare will not break down and become soft in the microwave. Many other cookware brands fail in the microwave because they can’t handle the rapid temperature changes.

Can I Use Vintage CorningWare in the Microwave?

Yes. The recipe for CorningWare has not changed much over the years, and vintage items can withstand the same high temperatures as modern cookware. However, older models might have traces of lead on the exterior.

How Can I Test My Cookware to See If It’s Microwave Safe?

Place your item in the microwave with a microwave-safe measuring cup containing 1 cup of water. Microwave the items on high for 1 minute, then check the item that you are testing. If it is hot, it is not microwave safe. Only use items that remain cool after running this test.

putting ceramic bowl on microwave
Image Credit: Quality Stock Arts, Shutterstock

Microwave Safety Tips

  • Don’t soak your CorningWare to get it clean. Soaking can help loosen stuck-on food, but it will also create tiny cracks in the surface that can reduce its ability to withstand high temperatures. If enough cracks form, the CorningWare might shatter.
  • Look for the words, “microwave safe,” or a symbol that looks like a microwave with squiggly lines to ensure that you can heat an item in the microwave.
  • Always read over the microwave owner’s manual to ensure that you are using it properly, and follow all the guidelines.
  • Always wear oven mitts or pads when removing hot items from the microwave, to prevent burns.
  • Never use a microwave if the door doesn’t close securely or if there are problems with the latch, hinges, or seals that might enable radiation to escape.
  • Don’t use a microwave if it operates with the door open.
  • Don’t put any items in the microwave that can catch fire, like paper plates or paper towels.
  • Regularly stirring can help distribute the heat, enabling your food to heat more evenly.
  • Cover the food while you are microwaving it because any food that contains liquid or fat can explode, creating a mess in your microwave and possibly ruining your meal.
  • Don’t place your microwave near the stove, or it can overheat.
  • Keep plenty of space around the vent.
  • Don’t microwave sealed food. Instead, poke holes or lift the corner to enable air to escape to prevent an explosion.
  • Always open heat containers away from your face to prevent getting burned by steam.
  • Place a microwave-safe spoon in a liquid that you are heating to prevent surface tension that will cause the water to exceed 212 degrees Fahrenheit, which can lead to an explosion and severe burns.
man using microwave
Image Credit: Pixel-Shot, Shutterstock

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CorningWare is a microwave-safe cookware that can handle temperatures well over 400 degrees Fahrenheit. The surface is durable and is unlikely to crack or break while using it, even if you drop it, and it won’t absorb stains or odors that can degrade the quality of your food. However, you’ll want to avoid soaking it in water for too long, which can create microscopic cracks that can reduce its ability to withstand high temperatures. Antique CorningWare is also safe to use in the microwave, but the exterior might contain small traces of lead.

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Featured Image Credit: Corningware (Image Credit: Melissa Highton, Wikimedia Commons CC BY-SA 4.0)


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