Are Mason Jars Oven Safe (How To Decarboxylate Cannabis With A Mason Jar)

If you want to carboxylate cannabis, there are a few varying benefits of doing so in a mason jar in comparison to using a baking sheet in the oven. 

Are Mason Jars Oven Safe (How To Decarboxylate Cannabis With A Mason Jar)

Using a mason jar minimizes the amount of strong and overpowering cannabis odors you can get. However, one of the primary benefits concerning the terpenes which can evaporate in the process.

They will stick to the glass and if you use the same jar for infusion, you can preserve them! 

A final benefit is that there is no direct contact with the oven’s airflow, so it is much less likely that you will burn any of the cannabis as you heat it. 

It is beneficial, however, mason jars are glass, and there is always a strong concern with ever putting glass in the oven, and the precautions that you should take when doing so. 

Is It Safe To Bake In Mason Jars? 

While there are many benefits of using mason jars for decarboxylating cannabis, the actual act of doing so should be approached with the utmost caution.

Plenty of people have approached the possibility of baking in mason jars, making desserts, and treats in them, and the advice is always solidly against doing so, but why?

Well, mason jars were never designed to be baked, they are vulnerable to temperature fluctuations as they are not made from tempered glass, and the dry heat put out by an oven can be dangerous. 

Of course, thermal shock is another problem and is the leading cause of breakages, it is advised that those who do canning, avoid using oven sterilization.

When a jar like this breaks it is usually the case that it will shatter into some very sharp pieces, which is not something you want in the place where you also make food!

There is also the risk of botulism which can be fatal, and there should be no risk taken with this. 

What Temperature Can Mason Jars Withstand? 

Mason jars can withstand a certain degree of heat, however, the thermal shock differential is generally the range of change that glass can withstand before it experiences shock and damage. 

For any canning mason jars, this range generally sits at around 90 degrees Fahrenheit, which is not particularly hot. However, this is in concern to mason jars with untempered glass. 

If you happen upon mason jars with soda-lime glass material composition, you could heat them to 392 degrees Fahrenheit.

What Temp Do You Put Mason Jars In The Oven?

If you have an oven-safe mason jar, such as one that has soda-lime glass, you should be able to put it in the oven at 275 degrees Fahrenheit. This should be hot enough for sterilization. 

Can You Put A Mason Jar In The Oven At 200 Degrees? 

Mason jars that are made from soda-lime glass can be heated to 392 degrees Fahrenheit maximum. However, this does require a very slow heating process.

Are Mason Jars Oven Safe (How To Decarboxylate Cannabis With A Mason Jar) (1)

This may include you previously heating the mason jars under warm and then hot water before you place them in the oven. 

However, make sure the glass of the mason jars is suitable for the process before undertaking it.

How To Decarb In A Mason Jar

If you choose to decarb your cannabis in a mason jar, you need to be prepared to do so, you need to choose appropriate mason jars as to ensure that the process is safe, as well as have other items ready for use. 

Let’s walk you through the process of doing this safely and securely, so you get great decarboxylated cannabis, but have no resulting issues from doing so as well! 

What You Need

  • Oven-safe, soda-lime glass mason jar(s).
  • Kitchen towel.
  • Oven gloves.
  • Cannabis.
  • Baking tray.


  1. First, set your oven to 220 to 240 degrees Fahrenheit and place the oven rack in the middle. 
  1. Break up your cannabis until it is small, around the same size as a grain of rice, and put it carefully into a mason jar, then carefully screw the lid on. 
  1. Now, you want to lightly wet your kitchen towel, then lay it over your baking sheet, putting the mason jar on top of the towel, on its side. This damp towel will help to anchor the jar onto the baking sheet, preventing it from falling over. 
  1. Now, place the baking tray in the oven for an hour. 
  1. Every 15 minutes, remove the mason jar from the oven with your oven gloves, giving it a good shake to ensure that the cannabis is evenly dispersed. 
  1. After the hour is complete, take the jar from the oven, allowing it to cool for around half an hour before you store the cannabis or use it for cooking! 

Note: Do not place the mason jar upright, or on an oven shelf with no baking tray or towel.

These things help to keep the jar secure and safe inside your oven, this way even if there is a chance that the glass should break it is less likely to spread everywhere, less dangerous, and easier to clean.

It also allows for a better heating process as well! 


You can use mason jars to decarboxylate cannabis, however, when you do so, make sure you choose the right type of mason jar, and that you proceed with caution.

The last thing you want is broken shards of glass in your cannabis! 

Always proceed with caution before putting any kind of glass in the oven, and do not be afraid to explore different ways to use your cannabis, and ways to decarboxylate cannabis too! 

Mason jars are only one way, you can decarb via sous vide, mason jars, or simply by using a baking sheet in your oven. However, you choose to do so, always put safety first!

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