Can you microwave mason jars: Here are the reasons.

Can you microwave mason jars?
mason jars

Being widely used because of its versatile functions such as storage of either fresh cooked or left-over food, coffee mugs, stationary containers; however, Can you microwave mason jars? or Can you microwave cold mason jars to reheat your left-over food?. I’ve seen a lot of people facing the confusion of “are mason jars safe to microwave”. You will find most people say that mason jars are not microwavable. Well, that’s partly true. Because some jars are manufactured to be compatible with microwaves while others are not.

The assumption mentioned above exists as since the time mason jars were created by John Landis Mason as a canning jar in 1858 they have been often made of untempered glass. Moreover, they are normally designed for storing home canning recipes, cold beverages, room temp storage. Therefore, Mason jars are not meant to be put in the microwave. However, the assumption is no longer 100% true because there are plenty of mason jars productions manufacturing heatable mason jars.

In this article, Bourbon O will help you answer whether or not mason jars are microwaveable with detailed explanations, provide you with some tips when you put mason jars in the microwave.

Can you microwave mason jars

a great picture of mason jars
Mason jars

As I briefly answered above, it depends on what type of glass that Mason jars are made of to decide whether or not they are microwaveable. We will explain and help you understand why one is microwaveable while the other isn’t.

Read more: Instructions on how to drink non alcoholic limoncello

Normally, Mason jars are produced with the main function of storing cold beverages, home canning recipes, or food at room temperature. So, the manufacturer uses normal glass which does not withstand high heat to produce them. In turn, they can save their cost in the production process, so they can keep the price of Mason jars affordable with most buyers. So, no matter how many people tell you it is fine to bake Mason jars when using Mason jars that do not explicitly indicate they are “microwave safe”, it IS NOT a safe or healthy option to do that.

Since they are made of normal glass, the temperature of Mason jars during heating up will change significantly, therefore it causes changes in the structure of glass which can cause the glass to shatter. That could happen due to the fact untempered glass may contain microscopically tiny bubbles, and if these bubbles expand with heat, your glass may shatter into razor-sharp shards.

On the other hand, modern Mason jars are made of tempered glass which seldomly does not cause shatter during heating up. Being carefully processed during manufacture, all the tiny bubbles will be removed from tempered glass. So, tempered glass can handle temperature changes and higher heat much better than ordinary glass does. Consequently, it will not be broken for the same reason as normal glass during heating up. And if it does break, it usually breaks into pieces that are a bit less like daggers than untempered glass. For that reason, it IS SAFE to microwave mason jars that are made of tempered glass as long as you can find an explicit indication showing they’re microwave safe.

However, while modern Mason jars that are made of tempered glass are microwaveable, their lids are often made of metal. As you might know, metal items are very dangerous when put in the microwave. So, remember to remove all the metal parts of your Mason jars before putting them in the microwave for safety reasons.

Even though some Mason jars are microwave safe, they still have some characteristics of glass. Therefore, you still have to pay thorough attention while heating up your Mason jars. It’s better not to put Mason jars containing frozen foods or beverages in the microwave for over 15 minutes. Because while the glass temperature changes rapidly from cold to hot, the jars will shatter. In addition to that, it’s best not to put mason jars containing something that requires a long period of heating in the microwave. And you should only put quick-heat items such as pre-cook pasta, or soup in mason jars.


  • Label: “Microwave Safe” on a Mason jar,. A “Microwave Safe” label does imly that you are safe to use it in microwave.
  • Test in microwave: Otherwise, testing them out for a short period of time(1-2 minutes) is a common way to know whether or not your items are microwaveable. Given a thin Mason jars, testing them in microwave is not a good option, unless you want it to shatter inside your microwave.
  • You can microwave cold mason jar, but you shouldn’t. Because the flexibility of every type of glass is not good, it’s important to never put mason jars containing frozen items in the microwave. Otherwise, there’s a high chance that it will shatter.
  • Dishwasher-safe mason jars are available. Repeated dishwashing, on the other hand, may scuff the surface. To retain the aesthetic looks, you may wish to hand wash them.

We recommend you should use them only for storage and canning if you don’t find any labels on mason jars.

Some tips while using mason jars

A great picture of mason jars
Mason jars as pickle containers
  • Even though microwaveable type of mason jars are not significantly afftected by the heat, it will absorb heat and become very hot to touch by your bare hands. You should use microwave-safe gloves to protect your hands from burning.
  • You should not switch the temperature of mason jars too fast. Otherwise, its structure will be broken.Therfore, beforing pouring any hot liquid into mason jars, you should warm it up first to prevent temperature rapid changes and vice versa.
  • When buying mason jars, I think mason jars with plastic lids are better option than with metal lids. Because when you use mason jars with metal lids for such a long time, the metal can corrode which make it hard to fully twist in and lead to spoil your food.

Sterilize mason jars tip

In the case of microwaveable mason jars, fill them with warm water, then put them in the microwave:

  • 1-liter capacity or less: 1-2 minutes.
  • 1-4 liters capacity: 3-4 minutes.
  • 3+ liters capacity: 5 minutes.
Mason jars as a cold food containers
Mason jars

Read more: Is It Safe To Use A Mason Jar on a Blender: Using Blender Guide

In this article, you have been provided the answer to the question “are mason jars safe to microwave?” and some safe, useful tips while using mason jars. To sum up, other than Mason jars labeled with “Microwave-safe”, they’re not microwaveable. Thanks for supporting us.

By Luong Tan

Luong Tan, the creative and passionate founder of Bourbono, is a multi-talented individual with a deep love for the culinary arts. An accomplished food blogger, cookbook author, and former Ambassador of US cuisine in Vietnam (2015-2016), Luong has been on a mission to share his appreciation for food with the world.

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