Are Mason Jars Microwave Safe? FIND OUT

Mason Jars, also known as “Ball Jars,” and “Glass canning jars,” are great recyclable products to store food. Also, some like to keep their drinks or use them for keeping overnight oats.

There are times when under the pressure of seemingly never-ending chores or in a hurry, we just want to take the mason jars out of the fridge and put them straight into the microwave oven. But the question arises, is the Mason jar microwavable? You may also like to learn – Is it safe to reheat food on a paper plate in the microwave? and are solo cups microwavable?

For quick reheating of leftovers and thawing food, check our recommendations for the Best Stainless Steel Microwave.

Are Mason Jars Microwave Safe?

Not every mason jar is microwaveable, you can find its safety in the microwave oven by checking the “microwave safe” label on it.

However, most of the newly produced Mason jars landing in the market are microwave safe. Regardless of their “microwave-safe” symbol, you should be very careful as the Mason Jars glass tends to get too hot to touch.

Now, the question comes about old Mason jars, are they microwavable too?

Older jars that have no label indicating their safety in the microwave should never be put into the microwaves. So, in that case, it’s better to find a microwavable bowl and heat your food in it.

Another main point is you should neither cook nor bake in a Mason jar nor you should put it in the oven as the jar can’t withstand longer heating time.

Precautionary Measures for Microwaving Mason Jar

Precautionary Measures for Microwaving Mason JarNow let’s talk about the precautions you should take before putting the Mason Jar in the microwave.

No Metal Ring or Metal Clasp

Always remove the metal ring or the metal clasp before putting the jar in the microwave.

Don’t Reheat for a Longer Period

Even if your jar is microwave-safe, you can only use it for quick reheating of food that doesn’t require too much time. The reason is, glass can only expand a little, and further heating can make the glass shatter due to excess strain on the glass.

Keep Kitchen Mittens Close

The glass jar absorbs microwaves and gets too hot to touch. So, always use kitchen mittens or a kitchen towel to take the Mason jar out of the microwave.

Keep Stirring

If the food in the jar is too dense, you need to stir it at intervals to heat the food evenly.

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Safety Tips for Reheating Liquids in Mason Jar

Do not keep any lid on the jar when reheating liquid in a Mason jar. The liquid comes to the boiling temperature in the microwave without even bubbling, and steam can build up underneath the surface, which can cause splattering, superheating, or shattering of the glass.

To prevent this, keep a non-metallic skewer, chopstick in the jar, and keep stirring in between.

Take out the glass jar carefully as steam can cause scalding and burning.

Frequently Asked Questions (FAQs)

Can You Put a Frozen Mason Jar in the Microwave?

Can You Put a Frozen Mason Jar in the MicrowaveAlthough you can freeze your food in the Mason jar, you can’t directly put your frozen glass jar in the microwave. Placing the frozen Mason jar in the microwave can cause thermal shock, and the glass jar can break into pieces due to sudden temperature change.

Frozen jar contents need to be thawed first at room temperature. To speed up the process, put the jar in the water bowl and change the water at frequent intervals.

After keeping it in the water for 30 minutes or so, you can put the glass jar in the microwave for reheating.

Can You Sterilize a Mason Jar in the Microwave?

Mason jars are being widely used to preserve pickles and jams. But before preserving, Mason jars need to be sterilized. People often wonder, is it safe to sterilize a Mason jar in the microwave.

Yes, you can sterilize the Mason jar in the microwave.

  • For that, first, check for any crack or imperfection in the Mason jar. If the glass jar has any crack in it, don’t use it.
  • Don’t use old or thin-walled Mason jars.
  • Wash and rinse the jar with dishwashing liquid thoroughly. Use a brush to remove any stuck dirt.
  • Keep the wet Mason jar in the microwave oven for 45 – 60 seconds in the microwave at high power or until it is dry.
  • Lids made of plastic or glass need to be sterilized the old-fashioned way on the stovetop.

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Is a Tempered Glass Jar Microwavable?

Yes, tempered glass jars are microwavable because they are four times stronger than ordinary glass. However, it is not recommended to cook food in a tampered glass jar.

How Long Can You Microwave a Mason jar?

You can only microwave a Mason jar for 2-3 minutes or use it for quick reheating of the food. The glass of the Mason Jar is made of soda-lime glass and doesn’t flex very well. If you keep it in the microwave for a long time, the glass will explode into pieces due to excess stress.

And if you are microwaving the mason jar for sterilizing, then a 1-liter glass jar should be microwaved for 1 minute only.

How Can You Tell if a Glass is Microwave Safe?

You can tell if a glass is microwavable or not by checking the manufacturer’s label of “microwave-safe.” If there is no label on it, then the best way is not to use it in the microwave.

But if you still need to check it, then you can test it by putting it in the microwave with another microwave-safe water-filled container on high heat for a minute. If, after a minute, the water is hotter than the glass, then you can safely use it in the microwave.

Can Mason Jars Withstand Heat?

Mason jars can withstand heat up to 60 degrees change from its normal temperature. So, if the glass is at 30 degrees at room temperature, it can withstand up to 90 degrees.

In layman’s words, Mason jars can’t withstand high heat and can shatter.

Wrapping Up!

Mason jars require utmost care with all precautionary measures in microwaving, even if they are considered safe for microwave usage. The Mason jars can explode if they get too heated or if glass expands beyond its limit. So, if you want to reheat food for a longer period, you should opt for another microwave-safe container.

About Amelia

Hello, I’m Amelia. Welcome to my blog KitchenUnder100.Com. Over here I regularly post kitchen hacks, reviews of kitchen tools, utensils and related articles. My mission is to search and recommend the best kitchen products, so you don't waste your precious time and money on anything that is not worth it.

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