The fermentation of foods has a long history. It was primarily used as a means of preserving food before refrigeration was available (I.E. for the vast majority of human history!) However, our ancestors also intuitively knew that fermenting foods made them more digestible and nutritious. As well as consuming fermented foods helped them stay healthy and strong.
Modern science has revealed that the primary benefit of eating fermented foods comes from the probiotic organisms they contain. Probiotics (“pro” = for, “biotic” = life) are live microorganisms that are beneficial to humans. Studies suggest that consuming probiotic organisms have a wide range of positive effects; including reducing inflammation, treating diarrhea and constipation, improving the immune system, minimizing or reversing lactose intolerance, and even reducing anxiety and improving cognitive function.
Health Benefits of Fermented Foods
The microorganisms that ferment food produce alcohol, lactic acid and acetic acid. These natural chemicals preserve the food by retaining nutrients and preventing spoilage.
Fermentation not only preserves nutrients, it also breaks them down into forms that are more easily digested. Dairy products are a good example of this. As we discussed in the manual, many adults don’t produce lactase, the enzyme needed to digest the sugar in milk (lactose). But Lactobacilli – the bacteria present in fermented dairy products – transforms lactose into lactic acid, which is much easier for humans to digest.
Fermentation even creates new nutrients that weren’t originally present in the food. Microorganisms produce B vitamins, including Folates, Riboflavin, Niacin, Thiamin and Biotin. Lactobacilli also produce Omega-3 fatty acids, which are essential for cell membrane and immune system function.
Basic Equipment and Guidelines for Fermentation
All types of food have some tradition of fermentation, but fruits, vegetables and dairy products are the most commonly fermented foods and the ones we will discuss in this guide.
Fermenting foods at home is quite simple, and requires only a few ingredients, some basic equipment, and time. At a bare minimum, you will need:
- A wide-mouth glass or ceramic container
- Filtered or boiled (to remove the chlorine) water
- Sea salt or kosher salt
- Fresh vegetables or fruit
If you’d like to ferment dairy products, you will also need some kind of starter. For yogurt, this can be as simple as one or two tablespoons of store-bought yogurt. For kefir, you’ll need to obtain “kefir grains” (not actually grains, but for some reason that’s what they’re called). I’ll make some suggestions for how to do this below when we discuss fermented dairy in more detail.
The basic process involves placing whole, chopped, sliced or grated fruits or vegetables in a brine of salt and water and leaving them at room temperature to allow the beneficial microorganisms to proliferate. Salt inhibits many harmful bacteria, but it permits the growth of Lactobacilli, the type of bacteria that plays an important role in fermentation. Salt also draws water out of the vegetables, which helps keep them crunchy.
Whey (the liquid that remains after milk has been curdled or strained) is used as a starter in many recipes as an alternative to salt. This is because whey already contains Lactobacilli, and thus can speed up the process of fermentation. This is convenient, but those with dairy intolerance or allergy may wish to avoid whey as a starter and stick with salt.
Another alternative to salt as a starter for fermented vegetables is a “vegetable starter culture,” which you can obtain from the online store Cultures for Health or from your local natural food store. Like whey, these starter cultures already have Lactobacilli in them, which makes it possible to ferment the vegetables without using salt.
Many coastal traditional cultures use seaweed as a starter because of its high sodium content. Seaweeds are also very nutrient-dense and one of the only dietary sources of iodine.
The fermentation time for each item depends on a number of factors; including the room temperature, type of starter and quantity of salt used, and the nature of the fruit, vegetable or dairy product you’re fermenting. In general, the longer you ferment something, the more lactose (sugar) is consumed and the more sour it will be. So, with kefir, if you’d like it to be completely free of lactose — because you don’t digest it well — you’ll probably want to ferment the kefir for at least 24 hours, and up to 36 hours. On the other hand, if you’re okay with lactose and you prefer a sweeter kefir, you may only want to ferment it for 12 hours.
Equipment
It’s important to use the right type of fermentation vessel. A key principle of successful fermentation is that the vegetables or fruit must stay submerged beneath the liquid at all times. This prevents mold from spoiling and is the difference between fermented — and simply rotten — food.
You’ll need a large ceramic or glass container with a wide-mouth that you can fit a cap or plate on top of such that you can press down on it to keep the vegetables submerged beneath the brine at all times. You’ll need to check back regularly throughout the fermentation process, and may have to continue pressing down on the cap or lid to keep the vegetables submerged. Placing a heavy object like a rock or a jar filled with water on top of the cap can be helpful here, because it will ensure that the vegetables remain in the brine.
You can certainly use any glass or ceramic container you have on hand that fits this description. That said, if you plan to ferment food in any significant quantity one of the best investments you can make is to purchase a special container designed specifically for fermentation. These have an airlock set-up that ensures that the vegetables stay submerged in the brine at all times.
You can buy these at the online store Cultures for Health, and they may also be available locally. A good starter option is the “Fermented Vegetable Master”, which is a one-gallon glass jar with airlock that currently sells for about $12. If you plan on making larger quantities of sauerkraut and fermented vegetables, the Harsch Fermenting Crocks are a worthy investment. We’ve got one at home and can make massive batches of sauerkraut and other fermented veggies that last a long time.
Resources
Books
The information in this guide is enough for people that want to do basic fermentation. If you get really interested in it and want to branch out and learn more, I’d recommend the following books:
- Wild Fermentation: The Flavor, Tradition & Craft of Live-Cultured Food, by Sandor Ellix Katz
- Nourishing Traditions: The Cookbook That Challenges Politically Correct Nutrition and the Diet Dictocrats, by Sally Fallon & Mary Enig
- Home Cheese-Making, by Ricki Carroll
- Making Great Cheese, by Barbara Ciletti
- The Joy of Home Winemaking, by Terry Garey
- The Vinegar Book, by Emily Thacker
- The Joy of Pickling, by Laura Ziedrich
Equipment and starters
● CulturesForHealth.com: a great source for fermentation vessels, starters, pre-made fermented foods, books and other resources related to fermentation.
● TheHappyHerbalist.com: another source for everything related to fermentation
● Gemcultures.com: a great source for starters and cultures needed for fermentation