Fermenting 101

Important Note: When you buy through our links, we may earn a commission. As an Amazon Associate we earn from qualifying purchases. Content, pricing, offers and availability are subject to change at any time - more info.

Fermentation has been used for thousands of years to preserve food and its nutrients. As humans have evolved, so have the ways that food has been collected, cooked, and preserved. Many cultures have existed on mostly natural foods for centuries, while many have shifted to diets of full of artificial flavors, sweeteners, and preservatives. As health professionals and scientists have been discovering, there seems to be a correlation between food additives and bad health. As a result, the trend to grow and preserve our own foods is on the rise. Some of the most common forms of food preservation are fermenting and canning food, as well as drying foods. As people notice the health benefits in fermented foods, it’s as if the subject has simply exploded. You may find yourself wondering exactly what it is, why should you do it, and how to begin. You might be surprised to find that food preservation, fermentation in particular, is actually very simple.

Fermentation is the chemical reaction that takes place when bacteria or yeast is used to break down a food. It’s essentially a controlled decay of the food, but over a long period of time. The most simple way to describe what’s happening in fermentation is that sugar in the food (or added into the milk, juice or tea) is broken down into an acid or alcohol.

Benefits of Fermented Foods

Fermentation is a well-known and ancient form of food preservation. Historically, fruits and vegetables from summer farm crops were preserved using fermentation so that there would be a supply of food available in the winter months, when food would be scarce. In the mid-1800s, Louis Pasteur gave us our first formal understanding of the science behind fermentation, demonstrating the transformation of glucose into ethanol by using living yeast. Foods that have been fermented can last on a shelf, under the right conditions, for several years. It depends, of course, on the type of food, how it was fermented, and the environment that the food is stored in. There are also other benefits to fermenting foods:

  • Enhances flavor. Foods can be fermented alone, or in combination with other vegetables and herbs, improving the complexity and flavor. For example, you can add garlic, peppers and onions to a jar of tomatoes or carrots. The fermentation process of just the tomatoes or just the carrots would enhance the vegetables’ flavor, but the addition of the onions, peppers or garlic greatly changes the flavor. This is not different from cooking with seasoning.
  • Numerous Health Benefits. The compounds produced during fermentation are being studied for potential health benefits:
    • Improves digestion. All vegetables contain bacteria, good and bad. Fermentation helps grow the good bacteria while eliminating the bad. The good bacteria break down the fibers in many of the foods you eat. The good bacteria create acidic fermentation byproducts which help make an optimal intestinal environment, killing off pathogenic bacteria that may enter your digestive system. Probiotics are a friendly, good bacteria that help grow the good bacteria in your gut, along the lining of your digestive tract. This is what’s called the microbiome. Having a healthy microbiome is thought to keep your immune system healthy, and to help with weight management. It’s suspected that diets rich in additives and artificial preservatives can deteriorate the health of your microbiome, leading to many health disorders. People are encouraged to consume natural foods prebiotics and probiotics that will encourage a healthy microbiome in order to maintain optimal health. Studies are being done to support the relationship between a healthy biome and improving conditions relating to obesity, IBD, constipation, diarrhea, colon cancer, allergies, asthma, type 2 diabetes and rheumatoid arthritis. Some foods that contain prebiotics – foods that have fibers that may encourage a healthy biome – include: apples, barley, cabbage, carrots, flax seeds, garlic, jicama, leeks, quinoa, and wheat bran.
    • May lower blood pressure.
    • May be anti-carcinogenic, anti-oxidative, anti-fungal, anti-diabetic, anti-inflammatory, and anti-atherosclerotic, anti-obesity, anti-asthmatic, anti-anxiety.
    • Helps the body produce nutrients. Good bacteria that are increased through fermentation add many B vitamins as well as vitamin K.
    • Can reduce gas, bloating, constipation, IBS, cramps, and diarrhea.              

Dangers of Fermented Foods and Risks You Need to be Aware of

The biggest danger to consider when fermenting your own foods is the possibility of contamination. There are some key points to follow when fermenting your foods so that you don’t grow and eat the bad microorganisms – the bad bacteria.

  • Before you begin using your preservation jars, be sure to sterilize them. Even brand new jars need to be cleaned. Just because they came from a factory doesn’t mean that they’re void of contamination. You should definitely clean jars that you’re re-using or recycling. If there are any microbes in the jar before you begin, you could end up growing them into your food.
  • Always wash your hands and your vegetables before you begin working with food. Make sure your knives and cutting boards are clean. Avoid using vegetables that have been exposed to pesticides.
  • Use filtered water.
  • Once you’ve added your vegetables and salt to the jars, it’s very important that every part of the food in the jar is completely submerged in the water. The fermentation process works in an anaerobic environment. There cannot be any oxygen in the jar touching the food. Having the food exposed to oxygen invites the development and growth of mold and bad bacteria.
  • Once the food has begun fermenting, you’ll be tempted to taste it to see how it’s coming along. If you open the jar to taste the food, be sure to use a clean utensil to extract the food from the jar. Pale clouded liquid in the jar should be okay. Any unusual, dark, quirky, green, black or brown colored growth, or anything that smells foul – throw it away. Remember the old rule: When in doubt, throw it out. Don’t let that scare you away from fermentation. Do your homework, use common sense.

Commonly Fermented Foods

Just about any vegetable can be fermented. Some of the most popular foods on the fermented foods list are cabbage (sauerkraut or kimchi), carrots, cauliflower, corn, beets, radishes, ginger, garlic, onions, and cucumbers (pickles). Use vegetables when they’re at their ripest, but not overripe. Vegetables are the easiest and require the least amount of ingredients (water and salt). Cheese, milk (kefir), fruit, eggs (even hard boiled eggs!), meat and tea (kombucha) can also be fermented, but the process is more involved than that of vegetables. Pretty much any edible food can be fermented. This doesn’t mean they’ll all taste good. It can be fun to experiment with different foods. You might find that some foods you don’t like raw can taste amazing when fermented. Foods with more sugars ferment the best. Meats require a great amount of care because meat can spoil very easily. Beginners should stick with vegetables to start and then graduate into levels where you’re combining different vegetables with various seasonings. After substantial experience, if you like, look into meats, cheeses and dairy.

Miso. If you’re pretty excited about fermented foods and healthy eating, miso deserves some of your attention. Miso is a thick paste that can be used in a variety of ways in the kitchen. Miso is commonly known for its use in soups, but it’s also good for making sauces and salad dressings. Using miso adds flavor to your foods. It’s been around for centuries, with apparent beginnings in Japan. It’s made by fermenting soy beans or other grains or beans with a safe mold, called koji. There are several varieties and flavors available commercially. A Japanese-style soy sauce which is made by fermenting beans with wheat and  has a subtle, less harsh salt tase. It’s different from the traditional Chinese-style soy sauce which is typically made with only soy and is very salty.

Different Types of Fermenting

There are three basic types of fermentation:

  1. Lacto-fermentation, also called pickling when using the salt-brine. This is the way vegetables are fermented. There are several different types of bacteria present on all vegetables, good and bad bacteria. Lacto-fermentation uses salt to ferment vegetables. The salt eliminates the bad bacteria and allows for growth of the good bacteria. With vegetables, the good bacteria are called Lactobacillus. The Lactobacillus convert lactose and sugars into lactic acid.
  2. Alcohol or Ethanol Fermentation. This process uses yeast, bacteria or other microorganisms to convert sugars into ethyl alcohol and carbon dioxide.
  3. Acetic or Yeast Fermentation. This is the type of fermentation that is used to make kombucha, vinegar and wine. It involves the interaction of different micro-organisms. It’s a yeast and bacteria fermentation. Sugar is converted to alcohol and acetic acid.

The process of fermenting foods and beverages can be a lot of fun. What may start out as a hobby for you could turn into a passion that also provides you, your family, and friends with foods that are healthy and delicious. It’s a brave undertaking to learn about food preservation, but it can be very rewarding. Start small, stay safe, and don’t be afraid to experiment. Remember… When in doubt, Throw it out!!

Common Fermentation Supplies

If you’re thinking of diving into food fermentation, here are some of the tools you’ll need to get started: cheese cloth (or other breathable fabric), rubber bands, an auto siphon or funnel for transferring liquids, bottle brush for cleaning bottles between uses, jars and bottles of sufficient proportion, and weights to keep your foods submerged in the liquid, sea salt (iodized salt will leave your food tasting like chemicals), thermapen or other type of liquid thermometer, and a room thermometer.

Try Fermenting at Home

When learning how to make fermented foods at home, start with this very simple process. In a nutshell fermenting is basically putting salt, water and vegetables into a jar and letting it sit for a few days. Here is a simple process to try if you want to get started fermenting today.

  1. Clean the vegetables and cut into desired sizes. Smaller tomatoes don’t need to be cut in order to be fermented. Place vegetables into jars that are used specifically for preserving. There are many brands to choose from. Note that the vegetables don’t have to be raw in order to be fermented. Cooked vegetables can also be fermented, though it’s less common.
  2. Cover the vegetables entirely with water. Weigh the jar of vegetables and water. Remove the water from the jar and add salt. The best way to determine the volume of salt is to add 2.5% weight of the jar of vegetables and water. Multiply the weight of the vegetables and water by .025. Use that weight of salt. Add that to the water solution that you removed from the jar. Mix it well, dissolving all of the salt. The type of salt isn’t important. Weighing is the best way to do this because the different types of salt could measure out in a spoon or cup differently. Weight is more precise.
  3. Pour the salt water mixture back into the jar of vegetables. Make sure that all of the vegetables are completely submerged. It’s best if you place something on top of them, such as a baggie filled with water or other weight.
  4. Cover with a lid. If the lid is very tight, you’ll need to unscrew it periodically to release pressure that’s growing as part of the process. Let the jar sit for at least 4 days.
  5. The temperature of the room that the jar is in will affect the rate of fermentation. The room should be between 60-75˚F. The cooler the room, the slower the process. The warmer the room, the faster the process.
  6. Once you’ve fermented to a satisfactory level, you can store the jar in the refrigerator or other cool dark place. This will slow or stop the fermentation.

Recent Recipes