Can You Microwave Mason Jars? (And Are They Oven-Safe)

Mason jars in recent times have become very popular as the replacement of the coffee mug. They are cost-effective, more convenient to travel with and look cool. The first mason jar was invented by John Landis back in 1858 as a canning jar. While it is still majorly used for this purpose, it is also used as a travel mug. Moreover, they are also used to store food, drinks, office supplies, or any other loose household items.

Mason jars are made of glass but not the tempered glass. This means that they are not capable of withstanding a high level of heat; however, they are good for freezing. Basic mason jars are not ideal for microwaving or putting in the oven. But modern mason jars are said to be safe for microwave use. How true is this? Let’s find out the truth behind this claim.

Can Ball Mason Jars Be Microwaved?

Yes, the Ball Mason jar is designed to be safely used in the microwave. People often have this confusion whether or not mason jars are microwaveable. This is because some jars are compatible with microwaves and others are not. Ball’s mason jar belongs to the former category.

However, when using a mason jar in the microwave, make sure that you remove the screw top and lid. This allows you to can and heat your food within a few seconds and serve your loved ones. Mason jars, to some degree, can bear the stress caused by heating and cooling, granted that it does not occur too frequently. These jars are typically made using annealed glass.

Can You Bake In Mason Jars?

People have been cooking in Mason jars for ages. In fact, oven canning started in the 1920s, but it has been considered as an unsafe cooking technique. This is because dry heat does not get to the center of the jar, and if it does, it is not hot enough to kill off the bacteria.

The glass used in Mason jars is not tempered to be used in the oven and is not ideal or safe for baking projects. These are designed store home canning recipes, room temperature storage, cold beverages, and crafting. No matter how many food bloggers tell you it is fine to bake in mason jars, it is NOT a healthy or safe option.

How Long Can You Microwave A Mason Jar?

People primarily microwave mason jars in order to sterilize them. Putting them in the microwave is the best option to sterilize them as opposed to doing the same on a stove. Here are some safe steps to follow while microwaving mason jars.

  • Thoroughly wash the mason jars and ensure that it is properly cleaned. You can use detergent or baking soda to clean the stubborn spots on the jar.
  • Thereafter, pour plain water into the jar and place it in the microwave. The duration you should keep the mason jar in the microwave depends on its size. If you are using a 1-liter mason jar, then you need to microwave for 1 to 2 minutes. The heat will kill all the bacteria in it.

Are Mason Jars Recyclable?

Mason jars are recyclable items; however, the rubber rings on the top cannot be recycled. When you take the jars to the recycling companies, they only take the jar and not the plastic rubber rings. The annealed glasses used to make these jars are recyclable material.

Are Mason Jars Freezer Safe?

We store a lot of things in the freezer like sauces, stocks, soups, seasonal bounties, leftovers, etc. And if you are trying to avoid excess use of plastic, then mason jars can be an excellent substitute for this.

You can store your recipes and other stuff in the mason jar and store them in the freezer for several months. But you have to be a bit careful; otherwise, you will be risking cracks. Below are few useful tips that will help you to safely freeze food in mason jars.

  • Mason jars manufactured by brands like Ball and Kerr, there is a thin freeze-fill line. This line is found just under the threads, approximately an inch away from the rim. A majority of their jars come with this line, and its purpose is to signify the maximum limit of liquids that you can safely fill in without risking any cracks on the jar when the content freezes and expands. When freezing anything in the mason jar, make sure you take care of this line.
  • Glass can crack due to thermal shock. So make sure you cool the liquid at room temperature prior to filling the jar.
  • Put the jars inside a shatter-proof container like a cardboard box before placing them in the freezer. This would ensure that other items do not knock into the jar, especially when you use a chest freezer.
  • Avoid exposing your mason jars to sudden heat. When taking out the frozen liquid, defrost it at room temperature before introducing it to the heat.

Are Mason Jars Oven-safe?

We see many DIY enthusiasts putting mason jars in the oven and cooking cakes and mini-pies inside it. If you can cook in a glass dish, why not use a glass jar?

While it all sounds logical, that is not the case. Using a mason jar in an oven can be seriously dangerous. These jars are made using untempered glass, which cannot bear the high heat from an oven.

According to reports, tempered glass is four times stronger than normal glass. Therefore they can easily clear the oven heat without experiencing any shatter.

But when you bake with a mason jar in the oven, you risk shattering the glass due to the heat pressure. And if the glass ends up shattering inside, then it might damage the oven. Moreover, you would need to clean out the whole appliance properly and remove even a tiny bit of glass otherwise; your future meals could be contaminated.

Even if you safely bake using a mason jar, it can still shatter when it would be placed at a cooler temperature, thereby risking injuries to the baker.

Are Mason Jars Dishwasher Safe?

Yes, mason jars are indeed safe to be used in a dishwasher. But before you put them straight in the washer, it is better to sterilize them to ensure proper cleaning.

You can sterilize the jar in a hot pot of water or in the microwave. If there are any leftover stains, you can use bleach to clean that off. To thoroughly clean the glass and the lid, use a mixture of salt and distilled vinegar. Scrub it using a soft-bristled brush and hot water. Using steel wool can scratch the lid and glass, making it look worn out fast.

How to Determine Whether or Not The Mason Jar is Compatible With Microwave?

A simple way to figure out whether or not the mason jar is microwave safe is to look at the label at the bottom for a sign that saysMicrowave safe.’ This symbol indicates that the jar has been tested to handle high temperatures.

Another rule of thumb to test the compatibility of these glass jars is to put it in the microwave for 1 or 2 minutes. But make sure the jar does not contain any food or even beverages.

You should only do this if your mason jar is thick; it is not recommended to use unlabelled thin mason jars on the microwave.

Along with the label that says microwave-safe, you would also find a label if the product is not compatible with a microwave.

How to Efficiently Handle Mason Jars?

If you want your mason jars to stay the same for a long period of time, then here are a few simple tips that would help you.

  • If you are using a mason jar as a tea or coffee thermos, you should get cozy. This is because the glass will get as hot as your hot beverage.
  • While canning, make sure not to transfer the mason jars directly from hot water to wet or cold counters. Put a heat-proof pad or towel and let the content cool prior to transferring it to the fridge.
  • Although mason jars are freezable, they are subjected to cracking and shattering at cold temperatures. When you put them in the freezer, make sure to cover them with a fabric or put them in a shatter-proof box so that they don’t clink against the other items in the freezer.

Final Thoughts

Mason jars have become somewhat of a trend these days, and you can find them in every kitchen. And why not? They are practical, versatile, affordable, and attractive. In recent times, we have seen people experimenting with these jars a lot, especially the social media DIY-enthusiast.

They are baking cakes and pies in mason jars. As tempting it may sound, you should never put mason jars in the oven. However, you can use mason jars in the microwave, given that the product is labeled microwave safe.