If You're Using Mason Jars for Everything, Read This First
While many are familiar with using mason jars as a kitchen organizational tool, reusable container, or drinking glass, there are a slew of other ways mason jars can also be used as a cooking vessel.
Mason jars are a great way to preserve foods for up to a year. There’s a multitude of ways you can go about preserving high-acid foods (think salsas, pickles, fruits) as well as low-acid foods (meats and such). You can reuse mason jars with new lids to continually store homemade preserves.
Usually, the method requires a water bath to sterilize the mason jar and insure the container against potential damage. But the process of a boiling water bath has caused confusion for mason jar enthusiasts who wish to incorporate the container into other types of cooking or baking.
Social media users, as well as various Reddit food threads, have struggled to define whether or not it is safe to use a mason jar as a cooking vessel.
After speaking with the quality assurance team at Newell Brands, the company that manufactures Ball Mason Jar products, we have the definitive answer – you cannot expose your mason jar to prolonged dry heat from your oven.
The issue is that mason jars are not made of tempered glass – hence why you need to submerge the jar in a hot water bath when canning. If you were to put piping hot foods or liquids into a room-temperature mason jar, you could risk thermal shock to the glass, and the container would shatter due to the extreme temperature differences.
Newell Brands' team doesn't endorse using Ball or Kerr canning jars in ovens or for baking projects. If you were thinking that your mason jar might be a great vessel for extended cooking in an oven, you’ll need to find other glassware that is tempered and can withstand high temperatures without the risk of shattering or explosion.
For more information on canning at home, and how to use mason jars appropriately in a warm water bath, Ball has put out a thorough how-to guide on their website.
Mason jars can help you to preserve foods, store leftovers in your kitchen, hold ice cold beverages on a hot day, and even are great for displays and light crafting in your home – but they have no place in the oven.