Understanding Ferments

Fermenting is so popular these days, but while it is a relatively easy and safe process, there is still plenty of misunderstanding and mystery surrounding it, and I have seen way too many ferments go into the trash. Before putting a lot of time and money into making your ferments, make sure you understand the basics.


When we are fermenting, we are growing beneficial bacteria, called lactobacillus. This is the same beneficial bacteria that colonize our guts and help us digest our food, which is why raw ferments are so good for us to eat. It is also the same bacteria we use to make cheese and yogurt. Most vegetables have lactobacillus on them naturally, so you don’t have to worry about providing this. However, if you are peeling your vegetables for some reason, you can add a small amount of whey drained from yogurt or left-over from cheese making.

Our goal with fermenting is to cultivate those beneficial bacteria. We want to provide optimal conditions for them while discouraging the not-so-desirable bacteria.


Water helps exclude air. Lactobacillus are anaerobic bacteria, which means “without air.” When vegetables rise out of the water and come into contact with air, then you begin to have mold problems. Use cheesecloth and/or a plate with a weight on top, a bag of water, a lid, or some other method to keep your vegetables submerged in the water.

Chlorine kills bacteria, so make sure to use non-chlorinated water.  If you don’t have a filter that takes out the chlorine, just let your water stand with no lid on it for at least 24 hours.

dilly carrots


Salt’s role in fermentation is to make the environment more favorable to the beneficial bacteria. With moist vegetables like cabbage and turnips, it helps draw water out of the vegetable so that it creates its own brine. It also adds flavor in my opinion. But it is not absolutely necessary for fermenting, and if you have blood pressure issues you can reduce or omit the salt altogether in some ferments.

Be sure to use salt that is not iodized because iodine kills bacteria.  Kosher salt or sea salt works well. Use 2.5% of the weight of the vegetables if you are fermenting high-water-content vegetables like cabbage where you are going to draw the water out of the produce. Use 3-3.5% of the weight of the water if you are using a brine for lower water-content vegetables like green beans or carrots.


The higher the temperature, the faster it will ferment. Vegetables fermented above 70° tend to be mushier. I prefer ferments that are incubated at a lower temperature, around 60°.  If your house is really warm, try to find a cool spot, but make sure you remember to check on it!  When your ferment reaches the desired texture, transfer it to a refrigerator or cold storage. This will slow down the fermentation, but won’t stop it entirely. Enjoy your ferment in the next few months. Remember that temperatures above 110° will destroy lactobacillus, so don’t can or cook your ferments for maximum benefits.


The longer you ferment your veggies, the more probiotics they will contain, but you also loose texture.  I find slightly crunchy ferments are a much more pleasant texture than the mushy sauerkraut of my youth. I usually ferment for about 1-3 weeks before putting my ferments in the refrigerator or cold storage to mellow further.  Check on your ferments regularly to catch mold beginning to form and to test for your preferred texture.


Fermentation crocks are great for large quantities, but I find wide-mouth mason jars to be way more convenient for most ferments. Mason jars are also less expensive and a great way to experiment with small quantities. Both of them are non-reactive and won’t impart a flavor on the ferment.

Fermenting doesn’t have to be scary. With a basic understanding, we can use our imagination to come up with delicious combinations of flavors without even using recipes. Fermentation is a safe, nutritious and affordable method of storing our summer bounty!



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