Can You Microwave Glass Jars? Is it Safe? Here’s What to Know

Microwave oven is one of the most used appliances in our kitchen. We use it for many cooking tasks, like reheating leftovers, warming drinks, and even baking.

And many of us keep our drinks in glass jars or mason jars, which brings us to the questions – Can you microwave glass jars? Is it safe to put a glass jar in the microwave?

Well, there are no absolute answers to those questions. We’ll answer the questions concerning putting glass jars in a microwave, and nail down the reasons why.


Jump to:
1. Can You Microwave Glass Jars?
2. FAQs About Microwaving Glass Jars

Can You Microwave Glass Jars?

We all want a simple way to warm food items – put the food in the glass jar, microwave it, and get it ready to serve. Is it safe to microwave glass jars, though? Can you microwave glass containers?

The short answer is: often nope. Generally speaking, jars made of ordinary glass can’t be put in microwaves or convection ovens.

Most jars and containers made of ordinary glass material on the market can’t withstand high heat. When these glass jars are placed in microwaves, they will crack or even explode. That’s the big reason why you should be cautious about microwaving glass jars.


However, there are some special glassware on the market that can be heated by microwaves, most of which are made of heat-resistant materials, such as borosilicate glass.

These heat-resistant glass jars are often obtained after annealing and cooling process. That’s why they are far more stable than other glassware on the market, and why they can be cooked within microwaves.

You can find the “Microwave Safe” sign at the bottom of the glass products that are designed to be used in microwaves.

Stick to glass jars with the “Microwave Safe” label, and ensure yourself a pleasing and safe cooking experience.


Bonus Safety Tips:

  • You should never put glass jars in microwaves with lids on. Be it microwave-safe or not, glass jars with lids on will cause an explosion in microwaves. Remove the lid of canning jars before you heat them.
  • Most glassware on the market can stand the temperature change only within 60 degrees. If the room temperature is at 20 degrees, and you fill glass jars with boiling water, big chances are glass jars will crack. Preheat the glass jars with warm water first to reduce the temperature change, then fill them with hot water.

FAQs About Microwaving Glass Jars

1. Can You Microwave Mason Jars?
Many tend to use mason jars for the storage of coffee, milk, and even foods. And we all want to directly heat the mason glass of milk, coffee, and other items before serving.


However, not all mason jars are safe to use in microwaves. Just like glass jars, many mason jars are made of ordinary glass. That is to say, they are not designed to be cooked within microwaves.

Microwaving mason jars that are made of ordinary glass can lead to explosions. If you can’t find a “Microwave Safe” label on the mason jar, just use it for storage rather than cooking.

2. Can You Microwave Tempered Glass Jars?
Tempered glass are tougher than ordinary glass materials. However, tempered glass jars are not recommended to be cooked with food items in microwaves as well.

One of the reasons lies in that unhomogenized tempered glass, if used in an oven or microwave oven, bears the risk of explosion.

Furthermore, tempered glass jars contain mental materials. Once they are heated by microwave ovens, it could cause the risk of leaking toxic substances and contaminate the food items.

Wrap Up

In this post, we’ve explained the main reasons why you should be cautious about putting glass jars in the microwave, and answered some frequently asked questions about microwaving glass jars.

Hopefully, you’ll find the information useful. If you have any questions, leave a comment down below and we’ll discuss further.

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