Do you have to sterilize your fermenting jars

We live in a sterile age. The market is bombarded with bleach of every scent, disinfectant wipes, hand sanitizers, and more. There is no doubt we are a germophobic culture. But studies show that children exposed to the outdoors, farm animals, and other less-than-sanitary conditions have fewer environmental allergies and incidences of asthma than children that grow up in a more sterile environment. But what about our food? How clean do we have to be in our food preparation, especially when it comes to fermentation?

When I started canning my own produce, I sterilized everything. No way was I taking chances with the safety and health of my family. Plus, nothing is as disappointing as going into the pantry in December and finding a jar of home goodness with the seal popped because of the bacteria growing inside.

A couple years ago I learned that if you are pressure canning your food, there was no need to sterilize your jars. After all, if pressure canning didn’t kill what might be in them, boiling them certainly wouldn’t. Learning that sure took some of the work out of canning.

But what about fermenting foods? Surely, you don’t want any disagreeable bacteria overtaking the friendly beasties in your ferment. How do you prevent that from happening?

Do You Have to Sterilize Your Fermenting Jars?

Most folks have a dishwasher. If you run your jars through the dishwasher, there is no need to worry. The bleach in the dishwasher detergent, coupled with the extra hot water, will kill anything.

But if you do not have a dishwasher, how should you wash your jars? And what about the lids, weights, and airlocks?

To answer this question, I first did an Internet search. Unfortunately, I came up with little. Everything I did find pertained to home brewing beer. And with that process, sterilization is crucial. But I’m not brewing beer, I’m making sauerkraut. So I then consulted several books on the topic.

Most books didn’t even address the question. And to my dismay, one book even gave conflicting advice. When giving instructions for fermenting in crocks, not one mentioned sterilization. But when I turned the page for instructions on fermenting in a jar, the book said to sterilize.

Not satisfied, I asked the expert—Matt Gross of Fermentools. “Soap and water are good enough,” he said.

“Wonderful,” I said. “But why?” I mean, we’re not even canning this stuff. How can it be safe?

I took that question to one more book, Nourishing Traditions by Sally Fallon. Here is how she answered it:

Salt inhibits putrefying bacteria for several days until enough lactic acid is produced to preserve the vegetables for many months.

But that is not all.

Bacteria need air to grow. The key to a safe ferment is that you keep the food submerged beneath the level of the brine and then cover it with a lid. That is why we place a glass weight on top of the food and then, for added safety, add an airlock to the lid.

So you can relax. If you think that fermenting cabbage, cucumbers, and carrots is too much trouble because you have to sterilize everything, stop. As Matt said, soap and water are enough.


Fermentools’ fermentation lids for Mason jars are made in North America of surgical stainless steel to last a lifetime. Add to them our affordable glass weights, gasket, and airlock and you have the perfect kit for all your fermenting needs. Visit our store today!

Leave a Comment