This post will explain oven canning, and whether or not it’s a safe choice. Read on for the scoop on oven canning!
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Oven canning used to be popular around the turn of the 20th century, where it seemed a handy way to keep the house cooler (before air conditioning, better home insulation, etc) than water bath canning. Some found that their fruit and veggies canned held their shape better, even, when canned in the oven.
I’d imagine that if you’re reading this post you know someone who oven cans, OR you’ve seen those cutesy recipes where the baker is directed in baking mini pies or mini muffins in mason jars the oven. If you can bake in them, why couldn’t you can in them, is the thought.
Oven canning was determined unsafe by the Mass. State College Extension Service in 1940, in a 2 year study. In fact, many studies followed proving the same: Oven Canning is NOT safe.
Well, my Grandma does it and she’s fine…
I’ve never had anything happen to me when I oven can…
It’s hot in an oven, it’s hot in a water bath, so what difference could it make?
These ideas are what can lead to jars full of hot food exploding in the oven, the oven widow exploding, major injury to anyone around, and at the very least, a major mess to clean up.
Why can’t I can in the oven?
Watch the YouTube video version of this post below if you prefer!
Ovens do not heat evenly. The steady heat of a water bath canner or steam canner is even and steady- there’s no fluctuation.
Wet heat is also penetrative in a different way than dry heat. The processing time specified in a recipe is based on the heat penetrating to the core of the food in the jar. While a traditional water bath or steam canner penetrates and heats the food in the middle of the jar, the heat of the oven “roasts” the outside of the jar and the food next to the glass. Think of a time you’ve burned a piece of meat in the oven but the inside still wasn’t cooked. That doesn’t happen in a crockpot, right?
Mason jars are not designed to be baked. They were designed for water bath and steam canning. They were never intended to be roasted.
By 1945 the National Safety Council made the bold claim that oven canning was outright dangerous and actively advised canners against it. They also warn against damage to kitchen appliances and equipment, which I think is a very valid warning as well.
My official recommendation is that oven canning should not be attempted.
That said, I have a friend who oven cans. Her mom does it, so she does it. She’s careful, she uses new jars, etc, but in my mind, her most likely risk is a huge mess and I’m not about to join her.
I personally am tired of cleaning by the end of any given day and cleaning up cooked food mixed with shards of splintered glass from inside the oven sounds like a fate worse than death.
Even if a canner today avoided (somehow…I don’t know how to avoid explosion but let’s say it was avoided) the door of their oven exploding, the risk of a huge mess seems pretty great. The injury possible from an oven canning explosion (so painful and very serious) seems small, but nonetheless a risk indeed, and one I’m not interested in taking.
I want canning to be fun, fast, and easy. That’s why I only practice myself and teach others techniques that are USDA approved and sensible for a busy mom and modern family. Explosions in the oven just don’t seem like a busy mom dream come true, right?
If you’d like to learn more about canning, check out the Canning for Beginners Ebook Bundle. All my ebooks: Steam Canning for Beginners, Canning 101, The Canning Essentials Workbook, and more at over half off in one bundle. You’ll also get 2 recipe ebooks as well!
I promise water bath and steam canning is super fun and safe. If you’re new to canning, sign up for the Free Canning Basics Course where I’ll pop into your inbox with simple lessons to get you started canning right away, the easy way!
For another myth-busting post, read about why simmering your canning lids is OUT here!