Substitute glass jar for Mason jar in pressure cooker I'm trying to make a recipe in my Instant Pot that calls for ingredients to be placed inside a Mason Jar, which is then put in the Instant Pot filled with water.  I have a glass jar with a metal screw on lid--similar to a Mason jar, although a little wider in comparison--but I'm not sure if there's anything specific about the construcion of a Mason jar that makes it uniquely suited to withstand a pressure cooker.

Can I use my glass jar in the Instant Pot pressure cooker??
Jars that are not made specifically for canning are not safe in a pressure cooker.   There are several manufacturers - "Mason" has become a generic term.  

If you are preserving, you need a special lid with the rubber rim to correctly seal the jar.  Do not reuse jars from food bought at the store.