“Does canning kill probiotics in fermented foods?” Samantha A. (@SAmesInfo) asked on Twitter. I’m sharing my thoughts below in today’s #AskWardee.
The Question
Samantha A. asked me on Twitter:
My Answer
Before answering this question, it’s important to know what makes fermented foods and veggies so special.
You’ll find 2 main ingredients in fermented veggies… the vegetables and foods themselves and salt.
Yet, if you look deeper, you’ll find other smaller wonders inside that crock or jar:
- probiotics — beneficial organisms that are so good for your gut
- enzymes
- vitamins
- minerals
- beneficial acids (vinegar and lactic acid)
So the question is… what does heat and/or pressure do to these ingredients?
To be more specific, if you took a jar of sauerkraut and canned it, what would happen to the probiotics, enzymes, vitamins, minerals, and beneficial acids?
Would they make it ok? Or not?
Does Canning Kill Probiotics In Fermented Foods?
The answer is… it’s not pretty. Mostly, they don’t make it through the heat and/or pressure of cooking, much less canning or pressure canning.
The probiotics die. The enzymes expire. Many vitamins are lost.
(The minerals are ok. The acids should make it.)
So, to me… it’s not worth it to preserve fermented foods through canning.
Losing out on the probiotics, enzymes, and vitamins? Which are really the whole point of creating fermented foods?
Much better to keep them fresh. 🙂
Which brings me to another question: what is the best way to preserve fermented foods?
The Best Way To Preserve Fermented Foods
You really have 2 choices for preserving your fermented foods. They both involve cold storage (like a cold cellar or fridge) or the freezer.
In either case, the probiotics, enzymes, and vitamins are preserved.
If you use fridge-type temperatures, the ferment will continue to age, though more slowly. In the fridge, the organisms are just warm enough to keep eating and growing. In fact, aged sauerkraut gets more yummy after a few months!
Speaking of which, have you seen my new video on making sauerkraut in a stoneware crock? No? Here it is!
If you choose the freezer, it’s like time stands still for the ferment. 🙂 Over time, you will have loss of probiotics, but it’s still a very good way to just keep it the way it is. Then thaw and eat when you’re ready.
Tip for freezer: Double or triple bag if freezing in ziplock bags to keep freezer burn at bay.
The Bottom Line
No, canning is not the best way to preserve fermented foods. Too much of the good stuff is lost under heat or pressure.
If you do want to preserve fermented foods, move them to cold storage — the fridge, a cold cellar, or a freezer.
Want more info on fermenting? Grab my free fermenting formulas cheat sheet so I can share the basic recipe formula for all kinds of ferments — krauts, pickles, salsa, relish, beverages, and more.
For More Information:
How do you preserve your ferments?
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How cold is cold storage? I have a cold, dark basement but I am concerned that my sauerkraut will go bad before I can eat it. How long should it last in a cold basement? What will happen to the taste?
Hi Lisa,
We like to use our fridge for cold storage. A basement isn’t quite as cool as fridge temps (usually) but you can still use it.
The warmer temp will result in a shorter shelf life. It’s hard to say how long exactly. It could be several weeks or a few months. The ferment may become tart and the veggies could get mushy.
As a child I knew someone that made kraut every year in a big crock, kept the crock in the basement and it lasted most of the winter. This was in a cold mid-west state so that may have helped. 🙂
~Millie, TCS Customer Success Team
Question: vinegar is a fermented food. But if I am buying a jar of it, even if it is raw apple cider vinegar with the mother, from a shelf in the grocery, it has been “canned” right? So the probiotics have been killed?
And the vinegars that say they contain the mother, they don’t seem to have anything in them that looks like one. Can you explain that? Thanks!
Hi, Tracy,
If it is a true raw apple cider vinegar it will state on the bottle “unpasteurized”. If it states it contains the mother then the tiny small bits and pieces are part of the mother in which it came from. If you wanted to start your own batch it would eventually grow into its own mother.
~Peggy, TCS Customer Success Team
I’m interested in canning fermented pickles because I cannot have white vinegar. Can I can the jars after the cucumbers have reached the desired flavor. I’m not worried about losing the probiotics because I have other fermented foods but I want pickles for the winter. (I have 8 kids so fridge space is limited.) Thank you.
Yes, you can can them but they will lose probiotic benefits as you mentioned.
~Danielle, TCS Customer Success Team
I just read your comment about not using white vinegar. I’m currently working on my first batch of Polish pickles, which don’t use vinegar at all. You can look a recipe, or here’s a link to the one I just tried.
https://www.polishyourkitchen.com/polish-pickles-in-brine-ogorki-kiszone/?sfns=xmwa
I didn’t like the flavor of my fermented green beans. Can I rinse and can them – otherwise the alternative solution is to simply throw them out (I really do not want to do that. I want to reserve them but I strongly dislike this particular flavor :/
Hi, Jenn.
I’m sorry you don’t like their flavor.
You could try rinsing nad canning however they will likely still have a fermented flavor to them.
~Danielle, TCS Customer Succes Team
I have fermented whole tomatoes. If I use them in tomato soup or chili, how hot can the soup get before it kills the good stuff?
Hi, Jenny,
Great question! The beneficial bacteria will die at around 115 degrees Farenheit. I usually add any fermented food at the end of cooking to preserve the beneficial bacteria but a lot of cultures do cook with fermented food for the flavor. 🙂
~Peggy, TCS Customer Success Team
I was just reading about Bubbies Sauerkraut. They make a shelf stable product that slows down the fermentation process, but apparently doesn’t kill it. I would love to know how they do that.
This is not a complete answer, because I don’t know their process, but…
They sell it in the refrigerated section, and expect you to keep it refrigerated.