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Mason jars are useful dishes that are regularly used in the canning process. People are already using these jars in a variety of purposes, including baking and drink storage. If you’ve started using Mason jars often, you should know how to use them securely. We did the research and can tell you if it’s safe to bake Mason jars.

It is advised to avoid putting Mason jars in the oven. These jars are usually not constructed of oven-safe glass and may shatter under pressure.

Continue reading to learn why oven heating is dangerous, how to heat Mason jars, and other crucial facts!

Mason Jar History

An American tinsmith patented Mason jars in 1858. These molded glass jars are popular for home canning and food storage. Mason jar tin lids feature a rubber, airtight closure.

However, if you reuse your lid, you should not rely on that seal. When using glass containers for canning, always buy new lids. New lids provide an airtight seal, protecting your food from germs and spoilage.

Mason Jar Uses

Mason jars have a variety of purposes today, despite their origins in canning and preservation. These jars have evolved into a jack of all trades, with individuals using them for anything from beverages to décor.

Because Mason jars have grown in popularity, more individuals are utilizing them in dangerous ways. Several websites claim that Mason jars are oven safe. Some baked recipes require you to bake your food straight in the jar. Others advise sterilizing and canning your jars in the oven. Let’s look at why these approaches are dangerous and why you should avoid them!

How Do You Heat Mason Jars In The Oven?

Mason jars should not be heated in the oven! It is not a safe or effective way of heating and sterilizing your jar. Keep in mind that glass is a poor heat conductor.

If you chose to cook your jar in the oven, keep in mind that not all sections may heat at the same pace. Furthermore, excessive temperature fluctuations may cause your glass to break. The disadvantages of baking Mason jars significantly outweigh the benefits.

If you must heat your Mason jar, try running it under warm water. To securely warm your jar, gradually raise the temperature of the water. This procedure protects your glass from sudden temperature swings. Once your Mason jar is sufficiently heated, you may sterilize it in a hot water bath or put hot food into the container.

How Hot Can A Mason Jar Get Before It Breaks?

Soda-lime glass is used in the majority of standard-size Mason jars. This glass can resist temperatures as high as 392 degrees Fahrenheit before breaking.

The main issue with Mason jars is their low thermal shock resistance. The capacity of an object to survive fast temperature fluctuations is referred to as thermal shock resistance. Mason jars have a limited tolerance to temperature fluctuations. Even sudden fluctuations in temperature during sterilizing might cause these jars to fracture.

How Do You Know If A Glass Is Oven-Safe?

Tempered glass and oven-proof dinnerware are usually safe to use in the oven. Smaller glass dishes, such as cups and bowls, should not be used in the oven since they are not designed to resist high temperatures.

Before placing any glass plates into your oven, inspect them for flaws. A chipped or cracked dish is far more prone to break.

You should also avoid extreme temperature fluctuations. Only place your glass dishes in a prepared oven to avoid possible breakage caused by temperature variations. A preheated oven has already reached a consistent temperature. A consistent temperature will avoid uneven heating of your glass dish.

Do you need further information? Take a look at “Is it safe to use glass containers in the oven? [Learn How To Tell] “for further information!

Why You Shouldn’t Put Mason Jars in the Oven

The major reason they should not be used in the oven is because you cannot dry-heat mason jars to a temperature that would properly cook food without increasing the temperature to the point where the glass will break. This implies that the jars cannot be heated enough to cook food, therefore there is no other need to place them in an oven.

If you put tempered glass in a hot enough oven, the extreme temperatures will shatter the mason jars. At certain temperatures, all forms of glass may shatter, although tempered glass has an extremely low breaking point.

Tempered Glass Risks

Most mason jars are made of tempered glass by canning businesses. There is a temperature restriction for most canning techniques, which require heating or boiling the contents of the jars.

Mason jars may be placed in boiling water, but the temperature must only exceed 212 degrees Fahrenheit. This is an appropriate temperature for mason jars.

Ovens, on the other hand, reach temperatures far higher than 212 degrees, posing the danger of breaking the tempered glass. It is advised to avoid baking in a mason jar since you will most likely need to set the oven temperature much over 212 degrees.

Most bakers need temperatures closer to 350 degrees Fahrenheit, so baking is not a viable option for reusing your mason jars.

Assuming the mason jars are put in an oven that is hotter than 212 degrees, here are a few perilous circumstances to avoid.

  • When heated, the glass expands.
  • The glass will shatter into several small, sharp fragments.
  • The glass will burst due to the pressure, sending glass shards everywhere.

Mason Jar Baking Alternatives

Although mason jars are not oven safe, they may be heated! The trick here is to avoid very high temperatures, otherwise the jars would crack and shatter.

Here are a few safe mason jar options:

  • Food Storage
  • Decoration
  • Canning
  • Soups
  • Desserts
  • Storage Containers

Mason jars are composed of tempered glass, which cannot survive the heat of an oven. It can, however, survive boiling temperatures, freezing temperatures, and room temperatures.

While glass should not be frozen since it will fracture, it may be used to keep food and placed in the refrigerator. This allows up a plethora of possibilities, such as overnight oats and parfaits.

You may also keep dry products in mason jars at room temperature to make a fast snack or to store sugar or rice. Finally, you may boil items in these jars, allowing you to can them.

Whatever method you pick, it is evident that there are several solutions available that do not entail baking.

Other Ways to Use Mason Jars In the Kitchen

Though I don’t can with my mason jars (yet! ), I do utilize them in a variety of ways around the house. If you love mason jars as much as I do (pretty, useful, reusable glass with lids, what’s not to love? ), here are a few additional uses for them in the kitchen:

  • Custom spice blends may be stored in 4 oz jars, such as this Pumpkin Pie Spice Jar.
  • Make salads in jars. I’m always curious whether they are difficult to eat, but I’m willing to give it a go!
  • Pack your lunch leftovers.
  • Serve refreshing summer drinks like homemade lemonade.
  • Make your own iced coffee.
  • For some lovely kitchen décor, plant a small succulent.


Let the pans and baking sheets do the work. Mason jars are useful for many purposes, but they are not ideal for the heat of an oven.

As a result, we must state that mason jars are not oven safe. I hope this post helps to answer your mason jar questions!