The concentration of salt in vegetable fermentation greatly influences the microbial composition of fermented vegetables. Even the type of salt used can profoundly affect which types of microbes populate fermented vegetables. Learn the important role salt plays in vegetable fermentation and how to make low-sodium fermented vegetables safely.
Specific salt concentrations control initial microbial growth. Not all microbes tolerate or survive in the same salt concentrations. Some microbes like to grow in the presence of NaCl way more than others. So utilizing an exact salt concentration determines which microbes initially thrive in fermented vegetables.
Why is Salt Necessary in Fermented Vegetables?
Basically, salt roots for heterolactic (lactic and acetic acid-producing) Leuconostoc bacteria start thriving while discouraging alcohol-producing yeasts from thriving. This leads to a quick and safe drop in pH. Once Leuconostoc bacteria drop the pH below 4.5, only homolactic Lactobacillus bacteria can thrive. This is because the environment in the fermentation vessel is now salty, anaerobic, and acidic. This is an extremely “selective” environment, meaning only certain microbial species can survive such conditions. Once those Lactobacillus start thriving, we’ve achieved preservation via fermentation.
What Happens When There’s Not Enough Salt in Vegetable Fermentation?
First, let me say this: It is SO easy to use an exact salt concentration to create VERIFIED safe and healthy fermented vegetables. Just use a valid recipe, weigh your ingredients with a kitchen scale, use a fermentation weight, and allow fermentation to proceed for a long enough time. It’s quite simple. All foods have safety parameters. This is not new. This is not scary info. There are a few major causes for concern when using too little salt (or no salt) in fermented vegetables:
First, it’s yeasts that produce alcohol. These yeasts make alcohol, and some species can metabolize acids, which prevents a rapid drop to a safe pH. This can lead to many other issues. (especially concerning when root vegetables are involved)
The next concern is bacterial toxins and Aflatoxin (a mutagenic and carcinogenic toxin produced by Aspergillus fungi that grow on fruits and vegetables). Have you ever had blue, green, black, or grey fungus growing on your ferments? This is why you cannot just scrape it off and eat it. With a proper salt concentration, dangerous fungi are inhibited from growing. This inhibition is two-fold. The fungi don’t grow well in salt, and Lactobacillus spp. have the ability to inhibit the growth of Aspergillus fungi. Also, without a specific salt concentration promoting the growth of lactic acid bacteria, certain gram-negative bacteria, like E. coli, can initially thrive and produce toxins.
Lastly, sensory quality is a concern when it comes to hypothetical low-salt conditions in fermentation. You just learned that traditional salt concentrations between 2.5%-8% encourage rapid acid accumulation and anaerobic conditions. Thus, these two parameters inhibit the growth of undesirable microbes. These conditions also favor the growth of homolactic Lactobacillus over other heterolactic species of bacteria. The progression to homolactic fermentation by Lactobacillus spp. is vital in the flavor and texture quality of finished fermented vegetable products.
The Main Reason For Fermentation Problems
The main reason people experience fermentation problems is that they use an insufficient salt concentration. A specific, properly measured salt concentration effectively controls alcohol-producing yeasts, dangerous fungi, and gram-negative bacteria in fermented vegetables. This control of unwanted microbial growth is two-fold. First, undesirable microbes don’t “love” to grow in salty conditions. Two, desirable lactic acid bacteria thrive in salty conditions and out-compete undesirable microbes, having a protective “probiotic” effect on the vegetables.
Salt does this by simply encouraging the growth of Leuconostoc bacteria that produce acetic acid and lactic acid. Leuconostoc bacteria can out-compete any potential pathogens and yeasts for space simply because they like salt more than other microbes. These heterolactic fermenters produce so much acid that they limit their own growth and die off. This paves the way for our beloved, more acid-tolerant Lactobacillus to thrive. Then, we have preserved vegetables. Simple and perfectly safe!
How to Make Fermented Vegetables That are Low in Sodium
One option I suggest for those who wish to make fermented vegetables on low sodium diets is to use our fermentation recipes exactly as stated, and the salt concentrations listed in the chart found here. Once fermentation is complete, you can remove half of the liquid brine and then replace the liquid removed with apple cider vinegar or rice vinegar before placing it in the fridge. This results in a different flavor, but I enjoy it. It also cuts the salt content in half without compromising the fermented vegetables’ food safety and sensory qualities. Since you’ll pour half the brine out, you can save the salty brine for use in low-sodium wild heirloom culturing recipes like the one below.
Recipe for Low-Sodium-Diet Friendly Fermented Carrots Using Wild Heirloom Culturing
I call this technique of fermentation wild heirloom culturing. The microbes involved in the fermentation process come from wild fermentation. However, the microbes are sourced from other, already fermented, vegetables.
Wild heirloom culturing is similar to yogurt culturing, except here, it’s vegetables that are cultured. The source of starter culture is wild fermented sauerkraut brine. This method is foolproof, completely safe, low sodium, and very fast. Just like in yogurt making, this method only requires a short fermentation time. The only thing that may take time is making your own sauerkraut brine. So if you don’t have any already and you don’t want to wait, you can buy sauerkraut and use the brine if you don’t want to wait.
Here’s what you will need to make low-sodium fermented carrots:
- Sauerkraut Brine (the liquid from already fermented sauerkraut)
- Rice Vinegar or Apple Cider Vinegar
- Pickling Spices
How to Make Low-Sodium Fermented Vegetables| Low-Salt Fermented Carrots Recipe
The concentration of salt in vegetable fermentation greatly influences the microbial composition of fermented vegetables. Even the type of salt used can have a profound effect on which types of microbes populate fermented vegetables. Come learn the important role salt plays in vegetable fermentation and how to safely make low-sodium fermented carrots.
- Prep Time: 10 minutes
- Total Time: 10 minutes
- Yield: 12 Servings 1x
- Category: Fermented Foods
- Method: Fermentation
- Cuisine: american
- Diet: Vegan
- 300 Grams Carrots
- 175 Grams Fermented Sauerkraut Brine
- 100 Grams of Rice Vinegar
- 2 Cups of Boiling Water
- Wash the jar you plan to use and the lid.
- Wash your chopped carrots in cool water.
- Place your kitchen scale on the counter. Turn it on and set it to weigh in grams.
- Place a mixing bowl on your kitchen scale and tare/zero the scale.
- Add chopped carrots into the bowl on your scale until the scale reads 300 grams.
- Remove the bowl from your scale. Add two cups of boiling water to the carrots and blanch for 3 minutes. Immediately remove carrots from the boiling water after three minutes, and put aside.
- Place your empty, clean mason jar on the scale, and tare/zero the scale. Make sure your scale is still set to grams and add 175 grams of sauerkraut brine and 100 grams of rice vinegar to the jar.
- Add the 300 grams of carrots, into the jar. Add any dried spices you’d like to use. I used pickling spices.
- Place a lid on the jar, and allow to culture in the fridge for two days before eating.
- Taring/zeroing the scale with a container on it subtracts the weight of the container, allowing you to weigh only what is added to the container. After taring/zeroing the scale, the scale should read 0.0 with the container on it.
Keywords: carrots, low sodium, fermentation