A Guide to Fermenting Vegetables at Home
Fermenting vegetables can be a healthy way to improve your diet. We’ll show you why healthcare professionals think fermented foods and probiotics are beneficial to your health. Then we’ll explain two popular techniques for fermenting vegetables and the science behind the process.
Registered Dietitian Robin Foroutan points out in Food & Nutrition Magazine that there is a very long history of humans producing fermented foods; dating back to at least 6,000 B.C. While it’s original intent may have been for preservation purposes, evidence suggest health benefits were realized as far back as ancient Rome and China.
Meanwhile, today’s most popular fermented foods—rich in probiotics—include drinks like kefir (which is a fermented milk) and kombucha (a fermented tea.) They also include vegetables like sauerkraut (fermented cabbage,) kimchi (fermented napa cabbage and Korean radishes) and pickles (which are fermented cucumbers.) Finally, let’s not forget about yogurt, the most common fermented food!
If you are considering introducing fermented vegetables into your diet, then take a few minutes to read on and learn about this ancient technique of food preparation and its potential health benefits.
Health Benefits of Fermented Foods and Probiotics
According to research published in the Journal of Applied Microbiology by Parvez S, Malik KA, Ah Kang S and Kim HY; consuming fermented foods and probiotics can have a positive effect on your well-being. Together, they found it can:
- Improve the health of your intestinal tract.
- Enhance your immune system.
- Reduce symptoms of lactose intolerance.
- Reduce your risk for certain cancers.
Research from Dr. Josh Axe, a certified doctor of natural medicine, doctor of chiropractic and clinical nutritionist; finds further benefits:
- Preventing and treating urinary tract infections.
- Healing inflammatory bowel conditions.
- Managing and preventing eczema in children.
- Fighting food-borne illnesses.
As if those were not enough reasons to introduce fermented foods and probiotics into your diet, Dr. Joseph Mercola, D.O. points out that they can also help with:
- Mineral absorption and producing nutrients such as B vitamins and vitamin K2.
- Preventing obesity and diabetes, and regulating dietary fat absorption.
- Improve your mood and mental health.
- Preventing acne.
A Quick Warning to Consume Carefully
While the health benefits of fermented foods appear to be real, they may not always be good for you. Everyone handles fermented foods differently because their body’s unique microbiome.
It is best to start small with these foods if you are not accustomed to eating them, and consult your healthcare provider if you feel unsure about their affects on your body.
Fermenting Vegetables in Brine
Leda Meredith explains on The Spruce that fermenting vegetables to make sauerkraut, kimchi or dill pickles—among many other fermented foods—involves a process known as lacto-fermentation, which is a very simple process that requires a little bit of salt, water, an airtight container and the vegetables you want to ferment.
Salt is Important to the Fermentation Process
Together, the water and salt mixture is called a brine, and it is the key to successful fermentation. If the right concentration of salt exists in the brine it will kill the bad bacteria and yeast. This allows the good bacteria already present in the vegetables to flourish and preserve the food through the process of lacto-fermentation.
How salt concentration affects the fermentation process:
- If you do not add enough salt to your brine the bad bacteria and yeast will overtake the good flora and your food will spoil. Often, this results in the growth of mold and a putrid smell. If this happens, be sure to throw away the affected batch. It’s better to be safe than sick!
- If you add too much salt to your brine the fermentation process is fairly forgiving, but the taste may be overwhelming. Soaking the vegetables in water can help dilute the excess salt.
Keep in mind, even the good bacteria will have troubles growing in a brine with too much salt. An article from Northwest Edible Life suggests it is best to keep the salt concentration between 2% and 5% depending upon what the recipe requires:
- Adding less salt creates a weaker brine and allows the cellular walls to ferment further, which leaves a softer texture in the vegetables. It speeds up the fermentation process and is more likely to cause spoilage.
- Adding more salt will create a stronger brine, which better preserves the cellular walls and leaves a firm or crisp texture in the vegetables. It slows the fermentation process and is less likely to cause spoilage.
Using the correct amount of salt in the fermentation process is critical. It may be easy for veterans to successfully ferment their recipes, but newcomers have to be careful. In fact, some experienced fermentors preach the need for accurate salt measurements, especially for people still learning about fermentation.
It is Easier to Measure Salt with a Digital Scale
Holly Howe, author of Surefire Sauerkraut, says there are two reasons why you should measure by weight with a scale and not by volume with a measuring spoon:
- It’s not easy to calculate 2% of 3/4 cup of water. Instead, try to calculate 2% of 1000 grams. (1000 grams x 0.02 = 20 grams.) That’s much easier; even if you have to use a calculator.
- One tablespoon of fine-grain salt can contain more actual salt than a tablespoon of coarse-grain salt because of the variations in grain size and the empty space in between. However, if you measure by weight, 20 grams of fine-grain salt will always be the same as 20 grams of coarse-grain salt.
Howe has been running workshops on making sauerkraut for 10 years. Once, she started using a scale to measure the salt in her brine she noticed a dramatic reduction in spoiled batches. So, she started recommending her students measure salt with a digital scale, and they saw a reduction in spoiled batches as well.
How to Ferment Vegetables at Home
When fermenting whole vegetables—like cucumbers for a pickle recipe—it is common to use a wet brine, which is made with purified water and salt.
When fermenting chopped vegetables—like cabbage for a sauerkraut recipe—it is common to use a dry brine, or self brine, which uses salt to pull water out of the vegetable itself.
Fermenting Vegetables with a Wet Brine
Holly Howe’s Naturally Fermented Pickle recipe recommends a brine with a ratio of 3.5%-5% salt to water. Her technique for fermenting whole vegetables with a wet brine follows these basic steps:
- Add the cucumbers and spices into a fermentation vessel.
- Place a second container on a digital scale and reset it to zero weight with the tare function. Then, fill the second container with enough water to completely submerge the cucumbers.
- Mix your salt into the water—using an amount equal to 3.5%-5% of the water’s total weight—until it fully dissolves. (i.e. 1000 grams of water would require 35-50 grams of salt.)
- Pour the brine into the fermentation vessel and ensure there is enough to fully submerge the cucumbers while leaving a small gap of air at the top.
- Close the fermentation vessel and let it sit for 3 to 6 days at room temperature. Now you have pickles!
Sandor Katz of The Art of Fermentation adds:
While 5 [percent salt] would be extremely high in sauerkraut or kimchi, it is important to understand that 5 percent brine yields a much lower-salt product, because once the vegetables go into the brine, they absorb salt and release juices, thereby diluting the salt concentration by more than half.
Note: If you use a fermentation vessel with a tightly sealed lid, be sure to burp the vessel daily by opening it to release built-up gases. Otherwise, use a fermentation vessel, like these from Pickl-it.com, with an airlock to let excess gas escape without allowing oxygen in.
Fermenting Vegetables with a Dry Brine or Self Brine
Holly Howe’s SureFire Sauerkraut recipe recommends a brine with a ratio of 3.5%-5% salt to water. Her technique for fermenting chopped vegetables with a dry brine follows these basic steps:
- Place a mixing bowl on a digital scale and reset it to zero weight with the tare function.
- Prepare the vegetables by either chopping, shredding or grating them into the mixing bowl along with any desired spices.
- Sprinkle salt onto the vegetables using an amount equal to 2% of the vegetables total weight. (i.e. 800 grams of vegetables would require 16 grams of salt.)
- Mash the vegetables and salt together by hand for 2-10 minutes until the vegetables are thoroughly moist and a pool of water forms in the mixing bowl.
- Pack the vegetables tightly into your fermentation vessel, leaving no pockets of air and cover them with the remaining water—or brine—that collected at the bottom of the mixing bowl.
- Cover the fermentation vessel and let it sit for 1 to 4 weeks at room temperature. It can then store in a refrigerator for up to a year!
Note: When the salt is added it begins to extract water from inside the vegetables through a process known as osmosis, and it serves as the basis of the brine. Hence, the term self-brinning.
Howe also points out that it is important to keep the vegetables completely submerged in the newly created brine. Otherwise, mold can grow on any exposed vegetables. So, a weight is often needed to keep the vegetables fully submerged. Check her recipe for ideas on what you might already have to use as a weight, or pick up these specialty weights from Pickl-it.com.
The Chemical Process of Lacto-Fermentation
Different types of food and recipes will result in slightly different fermentation processes. However, S.E. Gould summarizes the process of fermenting sauerkraut in the Scientific American as follows:
The beginning stage of this fermentation process requires an airtight container for the bacteria leuconostoc to grow. Through anaerobic respiration, leuconostoc produces lactic acid and replaces all of the remaining oxygen in the jar with carbon dioxide.
Once the fermentation become too acidic—at a pH level of 4.6 to 5.7—the leuconostoc begins to die off, and lactobacillus bacteria begin to take over. The lactobacillus bacteria continue to produce more lactic acid until the fermentation process is complete; resulting in a final pH level around 3.
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