- Hahnbee Choi, Cert. CN
The Art of Fermentation | Lacto-Fermented Veggies
Updated: Aug 19, 2022
Paying homage to my Korean heritage, Korean foods have precise processes that best represent the tradition of fermentation. In Korea, there is kimchi (김치) - fermented cabbage, doenjang (된장) - fermented soybean paste, aekjeot (액젓) - fermented fish sauce, makgeolli (막걸리) - fermented rice wine and dozens more. These foods all have precise processes and stem back from thousands of years ago. Throughout the agricultural history of Korea, fermentation has been used to enhance flavors by using beneficial microorganisms to prevent microbial spoilage. Here the what, why, and how this long-established tradition can be added to the bowl.
What Is Fermentation?
Fermentation refers to the chemical process of converting sugars to acids, gases, or alcohol. There are wild ferments where the microorganisms are naturally present, for example, kimchi and natto. And starter cultures ferments require the addition of a starter culture such as kombucha and kefir. But the specific process that turns napa cabbage into kimchi and other fermented foods is called lacto-fermentation. This transformation occurs due to Lactic Acid Bacteria (LAB). The bacteria metabolize carbohydrates (sugars) in vegetables into lactic acid. Lactic acid ferments food, prevents spoiling, preserves nutrients, and fights harmful bacteria.
How Does Lacto-Fermentation Work?
Lacto-fermentation is a dependable method used for generations as harmful bacteria cannot tolerate salt well, ensuring the food is preserved and safe. Essentially, lacto-fermentation kicks out the bad microbes and invites the good ones in.
Noma Guide to Fermentation uses a nightclub analogy to describe fermentation vs. rotting.
“[Rotting] is a club where everyone gets in: bacteria and fungi, safe or unsafe, flavor-enhancing or destructive. [Whereas in fermentation], you’re taking on the role of a bouncer, keeping out unwanted microbes and letting in the ones that are going to make the party pop”
The beneficial bacteria in fermentation is called Lactobacillus. There are dozens of different strains used to ferment foods. Various strains of Lactobacillus have different benefits. For example, in Kimchi the 2 predominant species are Leuconostoc mesenteroides and Lactobacillus Plantarum. Leuconostoc mesenteroides initiate lactic acid fermentation and aids in inhibiting microbial spoilage, whereas Lactobacillus Plantarum harbors anti-inflammatory properties.
Stages Of Lacto-Fermentation
Following kimchi, here are the stages kimchi goes through to achieve lacto-fermentation.
Step 1 - Brine
The vegetable is submerged in a brine. This brine is salty enough to kill off unwanted bacteria, but LAB survives. The number of aerobic bacteria decreases while anaerobic bacteria dominate. Kimchi has robust anti-pathogenic and antimicrobial properties.
Clostridium perfringens, which causes food poisoning, was absent after 2 days of fermentation
Staphylococcus aureus and Salmonella typhimurium gone after 4 days
Listeria monocytogenes, Vibrio parahaemokyticus, and E. coli disappeared after 5 days
The number of lactic acid bacteria increased from 10^5 to 10^8
The antimicrobial effect resulted from organic acids and bacteriocin made during fermentation. Bacteriocin is an antimicrobial peptide produced by bacteria and can kill or inhibit related and non-related bacteria strains. So much so that they are being seen as a potential alternative to antibiotics.
Step 2 - Acid
The beneficial LAB organisms start converting sugars in the food to lactic acid. This creates an acidic environment, safely preserving the food. Along with lactic acid, CO2 is a by-product of LAB and gives fermented foods their bubbly kick.
Step 3 - More Fermentation
The best part about fermented foods is that it never goes "bad" per se. The LAB will continue to convert sugars until there is none left, and then it turns to vinegar, but this can take a very long time, and fermentation can be slowed by placing it in the fridge.
All food that enters the body goes through the digestive tract and is broken down so nutrients can enter the bloodstream. This is only possible with a healthy digestive system. A healthy gut contains a wide variety of beneficial bacteria and allows the body to be at optimal health and well-being as the gut microbes are the foundation of health. APC Microbiome Ireland and several other studies show that the health of the gut microbiome directly impacts the host's health. A 17-week randomized, prospective study in humans showed that fermented foods increased microbiome diversity and decreased “markers for inflammation.” The research found a decrease in 19 inflammatory markers due to the fermented foods. Notably found was interleukin-6 (IL-6), a typical inflammation metric and a “key mediator of chronic inflammation” such as rheumatoid arthritis, type-2 diabetes, and chronic stress.
As seen throughout literature, fermented vegetables are a tremendous source of lactic acid bacteria (LAB), a natural source of probiotics. The most common strains in fermented veggies are Lactobacillus Plantarum, L. Pentosus, L. Brevis, L. Acidophilus, L. Fermentum, Leuconostoc Fallax, and L. Mesenteroides. As a whole, veggies also provide antioxidants, prebiotics, phytonutrients, and fiber. The act of fermentation breaks down the veggies for optimal digestion and nutrient absorption as it pre-digests the sugars. Fermentation can also decrease anti-nutrients in foods such as seeds and nuts.
Fermenting Veggies At Home
Fermenting foods at home is relatively simple and packs a powerful punch of benefits. Cabbage-based recipes do best as they have been tried and tested to be the perfect fermented vegetable throughout history. Cabbage has an ideal amount of carbohydrates to support the fermentation process. Essentially this recipe is "dog-friendly" kimchi since this is the exact steps of gimjang (김장) -- the traditional and ceremonial process of creating and preserving kimchi in Korean households.
Veggies to ferment:
Cabbage (always include)
Suitable Fermentable Vegetables
Pink Himalayan Salt
Glass Container with lid
Salt is needed to brine the vegetables and draw out moisture. This will achieve the necessary liquid to the oxygen-free environment for fermentation & preservation to occur. When using salt, opt for Himalayan pink salt as it will not have iodine added and is dry. There are two ways to brine - wet brining and dry brining. Wet brining is when the vegetables are soaked in a salty mixture and fermented. Dry brining is when salt is sprinkled directly to allow the vegetables to self-brine. Sometimes both methods will be used, especially in human recipes. This recipe will cover both methods. Wet brining tends to be more beginner-friendly while dry brining takes a more skillful hand.
Wet Brining Directions
1. Wash and cut all vegetables. The smaller the pieces, the better.
2. Create a 2% brine for the wet brine.
Figuring out how to make a 2% brine requires some math, but there is also a chart below for those appalled by math (because same). However, for those interested in the calculations, take the volume of water in mL, which will equal the weight in grams multiplied by 0.02 (2%), which will equal the amount of salt needed in grams. For example, a 1 Liter pitcher is 1000mL. 1000mL X .02 equals 20 grams. In conclusion, 20 grams of salt would be added to 1L of water. Make certain all salt is dissolved in the liquid.
3. Place all veggies into a clean glass container and press down.
4. Pour 2% wet brine over until veggies are submerged.
5. Allow to sit at room temperature for 10-20 days, burping daily before placing in the fridge to slow fermentation. This step may take longer and shorter depending on temperature and humidity.
Dry Brining Directions
1. Wash and cut all vegetables. The smaller the pieces, the better.
2. Salt and brine vegetables. Start with a 1/4 tsp of salt for 0.5lb of veggies. Salt can always be added but not taken away -- add cautiously and in small amounts. This step is the most critical & trickiest part! Rub the salt in well and let sit for up to 1 hour. Rotate the vegetable every 20 minutes to ensure even brining.
How to know they are adequately brined
Properly brined veggies will be soft and bendable. Water will have been drawn out to create this texture, and there will be brining liquid from the vegetables. If no brine liquid exists, add more salt and wait to see if fluid comes out.
3. Add all vegetables into a clean glass container and press down. Pack the veggies down so there are no air gaps. Tamp the vegetables as much as possible.
4. Place a weight on (optional - read below) and screw on an air-tight lid. Leave to sit for up to 10-20 days burping daily before placing in the fridge to slow fermentation. This step may take longer and shorter depending on temperature and humidity. The vegetables will self-brine more over time.
Weights & Other tools
Weights and air-locks are often used to submerge the veggies under the brine and prevent spoilage. Well, these are perfectly fine to use; as someone who has done their fair share of fermentations (for humans and dogs), I personally do not use them. But for fermentation beginners, they can be helpful. If using a fermentation weight, there are many options online. Or wrap a small bowl or anything clean, small, and heavy in plastic wrap and press down on top of the veggies to keep them submerged. There are also fermentation kits, which can be used but are not essential.
Fermentation will begin to occur within the first few days. Depending on the temperature and humidity, it may ferment faster or slower. As carbon dioxide is a by-product of fermentation, it will build up within the vessel and need to be "burped," simply opening the lid and allowing the CO2 to escape. This is also an excellent time to check the progress of fermentation.
Mold & Kahm Yeast
Any fuzzy spots of any color are mold, and the batch is compromised and not safe for consumption. Kahm yeast is a white film that may form over veggies, but there is no need to toss the batch out if this occurs. Kahm yeast is not mold but aerobic yeast that forms when air bubbles get trapped below the surface and present itself when starchier veggies are used. If kahm yeast occurs, scrape it off, wipe sides clean, sanitize and dry the weight if using one, and continue fermenting.
How To Tell Fermentation Is Finished
When fully fermented, the vegetables should taste and smell sour and may even have an effervescent effect. Tiny bubbles may also appear, which is a good sign. Once these key points have been met, the jar can be placed in the fridge to slow the fermentation process. Depending on how the veggies were brined, they may last up to a year or more in the refrigerator.
Many recipes will call for a starter culture that adds probiotic strains to "kickstart" the fermentation process. But, I do not recommend this as most starters are dairy-based and will compete with the naturally occurring soil-based microorganisms present. All the starter microorganisms necessary will be in the fresh produce, naturally.
Like many whole food supplements, there is no exact dosage. But a general guideline is 1 tsp per 50lbs. Honor the dog's pace as it may not sit well with them at first if it is a new food. Rotating with any supplement to add variety to the diet is wise.
When Not To Feed
It is best to avoid fermented veggies when dealing with an animal with histamine intolerance. Fermented foods are plentiful in histamines, therefore, should not be fed.
Fermented vegetables have a long culinary heritage and have revolutionized the health & longevity world due to their discoveries. Without fermentation, there would be no delicious new flavors to enjoy or beverages such as wine and beer! Using this time-tested way of preservation, a little more vitality can be added to the bowl.