Humans have used fermentation for centuries to preserve food. Today, we know that fermentation also makes some foods more nutritious.
Like artisanal cheeses? Surely you’ve enjoyed a hand-crafted wine and a fine loaf of whole-grain bread. Cheese, beer, wine and bread are all fermented foods — as is a range of other foods. Fermentation serves a variety of purposes in food, as people discovered thousands of years ago. One is functional: Fermenting preserves foods. Another purpose is to improve or change food’s flavor. Less obvious, however, is that fermented foods contribute to good health. Following is an article about this age-old technique by Sandor Katz, one of the world’s leading fermentation experts. — MOTHER EARTH NEWS
Fermented foods and drinks are quite literally alive with flavor and nutrition, and are more common than you may realize. Cultured foods’ flavors tend to be strong and pronounced. Think of stinky aged cheeses; tangy sauerkraut; rich, earthy miso; smooth, sublime wines. Humans have always appreciated the flavors resulting from the transformative power of microscopic bacteria and fungi.
One major benefit of fermentation is that it preserves food. Live-culture yeasts and bacteria produce alcohol, lactic acid and acetic acid, all “bio-preservatives” that retain nutrients and prevent spoilage. Vegetables, fruits, milk, fish and meat are highly perishable, and our ancestors used whatever techniques they could discover — including wild fermentation — to store foods.
Fermentation not only preserves nutrients, it also breaks them down into more easily digestible forms. Soybeans are a good example. This extraordinarily protein-rich food is largely indigestible without fermentation, which breaks down the soybeans’ complex protein into readily digestible amino acids. Fermented soy gives us traditional Asian cultured foods, such as miso, tempeh and tamari (soy sauce), which have become staples in contemporary Western vegetarian cuisine. (Tofu is not fermented, but its manufacturing process makes it easier to digest.)
The fermentation process also creates new nutrients. Some live cultures have been shown to function as antioxidants, scavenging cancer precursors known as “free radicals” from the cells of your body. Fermentation also removes toxins from foods. Eating raw, fermented foods is an incredibly healthy practice, directly supplying your digestive tract with living cultures essential to breaking down foods and assimilating nutrients.
DIY fermentation is a journey of experimentation and discovery. Every ferment yields unique results, influenced not only by ingredients, but also by environment, season, temperature, humidity and other factors affecting the behavior of the microorganisms — think of them as your micro-livestock — whose actions make these transformations.
Fermentation generally requires little preparation or work. Most of the time that elapses is spent waiting. Home fermentation is about as far as you can get from fast food. Many live-culture foods get better the longer you leave them. Use this time to observe and ponder the magical actions of invisible allies.
I get so excited every time my crocks start bubbling and the life forces make themselves known. Even after a decade of experience, sometimes the process doesn’t go as I’d planned: Wines sour, yeasts become exhausted, insects infest aging crocks. Sometimes it’s just too hot or too cold for the organisms whose flavors we’re after. We’re dealing with fickle life forces, in some cases over long periods of time, and though we are making an effort to create conditions favorable to desired outcomes, we do well to remember that we are not, by any measure, in complete control. And remember that the prized cultures of a San Francisco sourdough or the finest blue cheese have roots in wild fermentations in someone’s kitchen or farmhouse long ago.
“Our perfection lies in our imperfection” is one of my mantras in this life. If you’re willing to collaborate with tiny beings that have somewhat capricious habits yet possess vast transformative powers, read on.
No cultured food is better known or acknowledged for its health benefits than yogurt. Perhaps you know some of the famous yogurt Lactobacillus organisms by name, such as acidophilus or bulgaricus. These lactobacilli, known to improve our intestinal ecology, are often marketed as probiotic supplements. It is mostly consumed sweet, though my favorite ways to enjoy yogurt are savory.
Cheesemaking involves many different variables. Milk can be transformed into a hard cheddar cheese, a runny Camembert, a moldy blue cheese or, for that matter, Velveeta. A particular cheese is the product of the particular milk of particular animals grazing in particular pastures, subjected to particular temperatures and particular microorganisms, and aged in a particular environment.
Tara is a Tibetan cousin of a ferment widely known as kefir, which originated in the Caucasus Mountains. Kefir and tara are distinguished from yogurt by the method of fermentation and the organisms that the fermentations involve. Kefir and tara are made with “grains” — colonies of yeast and bacteria that look like curds — that are strained out after fermentation, then reused.
Learn More: How to Make Your Own Yogurt, Kefir and Chèvre
Fermented vegetables complement any meal. Their tangy flavors accent the other food on your plate, cleanse the palate and improve digestion. I like to eat some fermented vegetable every day. A half-hour of chopping or shredding fills a crock that can ferment and then feed you for weeks. Keep crocks of different types of ferments going for variety. It’s very easy.
Cabbage and other Brassicaceae family vegetables (bok choy, broccoli, Brussels sprouts, collards, cauliflower, kale, mustards, and many more) have long been recognized as foods rich in anti-carcinogenic nutrients. According to a Finnish study published in the Journal of Agricultural and Food Chemistry, fermentation breaks down glucosinolates in cabbage into compounds called isothiocyanates, which are known to fight cancer. Other vegetables are often pickled in lactic ferments: Carrots, cucumbers, peppers and more can ferment in lactic acid brines.
In Western culture, bread is synonymous with sustenance. This is reflected in our slang, where money can be called “dough” or “bread,” as well as in our prayers: “Give us this day our daily bread.”
Yeast is used in bread making to make dough rise. Yeast is a fungus. The predominant type used in bread making is classified as Saccharomyces cerevisia: saccharo means sugar, myces means fungus, and cerevisia might seem more familiar if you think about the Spanish word for beer, cerveza. The same yeast that makes beer makes bread. Both of these processes developed simultaneously with grain agriculture in the Fertile Crescent region of the Middle East. Beers can start breads, and breads can start beers. In both, the yeast does the primary thing yeast knows how to do: It consumes carbohydrates and transforms them into alcohol and carbon dioxide. In bread, the carbon dioxide is the more important product.
Prior to the widespread availability of commercial yeast, people used any one of a number of methods to propagate their yeasts. Propagation can be as simple as using the same vessel repeatedly without washing it between uses. Most often, bread makers reserve a bit of yeasty batter or dough as a “starter.” A starter can be maintained for a lifetime and passed on for generations.
Live-culture alcoholic beverages are nearly universal, though there is some confusion about this. Into the 20th century, many ethnographers propagated the idea that fermented beverages were not found among “uncivilized” peoples. This is simply not true.
Though practices varied among different tribes in different regions, many native peoples of the Americas most definitely enjoyed fermented beverages. The alcohol that they did not experience prior to the Europeans’ arrival was distilled liquor, which is many times more potent and dangerous than fermented alcohol.
The context for making and consuming traditional fermented alcoholic drinks in many cultures was, as a general rule, communal and ritualistic. Some cultures created noisy rituals to generate excited — even angry — energy they believed helped yeast work more effectively. Other cultures — having the notion that the ferment needed peace and quiet and could be startled or scared by sounds and movement — approached fermentation processes with quiet reverence. Either way, the context was ritualistic and sacred. (Read more about this in Sacred and Herbal Healing Beers by Stephen Harrod Buhner.)
Foods with sugars — fruits and fruit juices — will ferment naturally into wine in the presence of wild yeasts.
Grains, however, do not spontaneously ferment to alcohol the way honey and water or fruit juices do. Making beer is more complex than making wine. For grains to produce any significant amount of alcohol during fermentation, their starches (complex carbohydrates) must first be converted to sugars (simple carbohydrates).
The standard way to accomplish this is called “malting,” which means germinating, or sprouting, the grain. Another way is through the action of molds. Amasake, the Japanese sweet rice ferment, is made from rice incubated with the mold Aspergillus oryzae. Sake, Japanese rice wine, is made by fermenting amasake with yeast.
Grains can also be fermented into liquid forms — not only alcoholic brews such as beer, but a huge variety of acidic beverages. Where I live in Tennessee, the earlier Cherokee inhabitants of the land drank a sour corn drink called gv-no-he-nv (the “v” is pronounced like the “u” in “but”). In its first week or so of fermentation, this thick, milky drink has the sweet flavor of corn accented by mild hints of sourness. After it ages a couple of weeks, gv-no-he-nv develops a strong, almost cheesy flavor.
Alcohol ferments, if left in contact with the air, inevitably become home to bacteria of the genus Acetobacter and aerobic yeasts, called Mycoderma aceti, that consume alcohol and transform it into acetic acid. Vinegar is an excellent consolation for your winemaking failures. It is a preservative in its own right, and healthful, with many delicious applications in cooking.
Different types of vinegar are generally distinguished by the source of the alcohol from which the vinegar is made. Wine vinegar is made from wine; apple cider vinegar from apple cider; rice vinegar from rice wine; and malt vinegar from malted grain beverages, such as beer. The cheapest and most common vinegar — distilled white vinegar — is made from grain, though it lacks the flavor and color characteristics of malt vinegar, and indeed its chief “virtues” are colorlessness and flavorlessness.
Learn More: How to Make Homemade Vinegar
Fermentation is a lot bigger than its food-transforming aspect. Fermentation also describes the process by which microorganisms digest dead animal and plant tissue into elements that can nourish plants. As the early microbiologist Jacob Lipman eloquently stated in his 1908 book Bacteria in Relation to Country Life, microorganisms “are the connecting link between the world of the living and the world of the dead. They are the great scavengers intrusted [sic] with restoring to circulation the carbon, nitrogen, hydrogen, sulphur and other elements held fast in the dead bodies of plants and animals. Without them, dead bodies would accumulate and the kingdom of the living would be replaced by the kingdom of the dead.”
This image helps me to accept death and decay. It is clear evidence on the physical plane that life is a cyclical process, with death as an indispensible part. It makes the harshest reality of life more understandable and more acceptable.
I feel there is wisdom in making peace with death. It will come. All I can do is embrace life as best I can, and when I die, I know, I believe, I have faith, that all that is me will continue to be part of the cycle of life, fermenting and nourishing and becoming myriad other life forms. My fermentation practice is a daily affirmation of this faith.