Is It Dangerous To Bake In A Mason Jar?
Mason jars have been around since 1858 but they are historically popular. While you may not be a food canner, Mason jars made canning foods at home widely accessible by a simple process of placing food into jars that contain an acid or sugar solution and have self-sealing lids. As The Ohio State University explains, these glass jars are then placed in a water bath that heats to 212 degrees Fahrenheit and boiled to kill bacteria. With the exception of the canning jar, the only other kitchen gear required is a pot large enough to hold your bountiful jars.
Mason jars are still the go-to for canning and preserving summer vegetables and fruits, conserving those precious pickings from modern day victory gardens, along with batches of grandma's secret recipes for chili and chicken soup. But today, these jars have become multi-use. They are used for artisan cocktails, serving up outrageous milkshakes and smoothies, storing grains and sugars, meal prepping layered salads, and even for elegant and rustic floral arrangements. Mason jars have come a long way! However, while these jars can withstand high heat from the canning process, you should not cook in them.
Mason jars are not meant for baked goods
Makers of these jars highly discourage baking in your canning jars so much so, they even provided Country Living a disclaimer saying, "We do not recommend baking in any size or shape of Ball or Kerr canning jars. The glass used for Ball and Kerr canning jars is not tempered for oven use and is not meant to be used in baking projects. The jars are safe to use for home canning recipes, cold or room temperature food storage, crafting, and cold beverages. The jars should not be used as bakeware, as most bakeware is tempered and can withstand greater temperature differentials."
While these jars are perfect for your farm table centerpieces and creating your individual charcuterie or "jarcuterie" for your next soiree, you do not want to mix up your next molten chocolate lava cake in one. The glass might not be able to withstand those high, dry oven temperatures and could break. Additionally, the University of New Hampshire says you should not bake and can cakes and breads in canning jars either, noting the possibility of botulism is real and advising home cooks to forgo being a creative baker for your own safety.