Historically, fermented foods have played an important role in the diets of most every society throughout the world. But beyond just the culinary choices and preservation advantages of fermented foods is the natural phenomenon of fermentation performed by the cells within our bodies that helps to keep us healthy. With fermentation becoming quite popular in modern culture, it is good to understand some of the basic science regarding fermentation and lacto-fermentation in particular.
Most people think about beer or wine when they hear the term fermentation. While certain yeasts are used to convert the sugars in grape juice or grains into alcohol, it is bacteria that are responsible for lacto-fermentation. The “lacto” portion of the term refers to a specific species of bacteria, namely Lactobacillus. Various strains of these bacteria are present on the surface of all plants, especially those growing close to the ground, and are also common to the gastrointestinal tracts, mouths, and vaginas of humans and other animal species. Many of us may be familiar with Lactobacillus acidophilus, the acid-loving bacterium commonly included in the process of making yogurt, but there are many others.
Lactobacillus bacteria have the ability to convert sugars into lactic acid through a naturally occurring fermentation process. The Lactobacillus strain is so named because it can readily use lactose, the sugar in milk, and convert it quickly and easily to lactic acid. So lacto-fermentation does not necessarily need to involve dairy products.
Lactic acid is a natural preservative that inhibits the growth of harmful, or putrefying, bacteria. This phenomenon allowed people to preserve foods for extended periods of time before the advent of refrigeration or canning. Lactic acid also promotes the growth of healthy bacteria in the intestinal tract. That is why lacto-fermented foods are considered probiotic foods. (Probiotic means “for life”.).
Beyond preservation advantages, lacto-fermentation also increases the vitamin and enzyme levels, as well as digestibility, of the fermented food. In addition, lactobacillus organisms produce antibiotic and anticarcinogenic substances that may contribute to good health. That is yet another reason to have an abundant amount of lactobacilli residing in our intestinal tracts.
The diets of every traditional society have included some kind of lacto-fermented food. In Europe they have been primarily dairy, sauerkraut, grape leaves, herbs, and root vegetables. The Alaskan Inuit ferment fish and sea mammals. The Orient is known for pickled vegetables and kimchi in particular. Check out the recipe: Raw Vegan Kimchi
Pickles and relishes are a part of the American food tradition. But the kind of pickles and sauerkraut that can be purchased in most grocery stores today are not at all the same products our ancestors knew. Since the advent of industrialization, most pickling is done with vinegar, which offers more predictable results, but no lactic acid. However, with just a little patience, instruction, and minimal supplies, it is possible to learn the time-honored art of lacto-fermentation.
How It Works
Lacto-fermentation really is more art than science. The science part is simple: lactobacillus (from a prepared culture, fresh whey, or just naturally occurring) plus sugar (naturally present in vegetables and fruits), plus a little salt, minus oxygen (anaerobic process), plus time, equal lactic acid fermentation. The length of fermentation can vary from a few hours to two months or more. The temperature of the room where fermentation occurs will determine the length of time. The ideal temperature is around 72°F, but warmer or cooler temperature will still work. (Some strains of bacteria require specific temperature ranges.) The length of time is dependent more on the flavor you prefer than anything else and since the flavor level of lacto-fermented vegetables increases with time you will want to sample often until you are experienced enough to know what works for your tastes. Just keep in mind that you don’t want to introduce a lot of oxygen to the fermentation process as this increases the chance of spoilage. Lacto-fermentation is generally done in an airtight container or a crock with a water seal that prevents air from contaminating the culture. If you have a reliable recipe to follow, you can make minor adjustments as you see fit.
The important thing is not to be intimidated by lacto-fermentation. You are not going to make your family sick by giving them home-fermented foods. Unless it smells unmistakably putrid (in which case common sense says throw it away), fermented foods are some of the safest foods you can eat. They are easy for even a beginner to prepare and it doesn’t take long to gain enough confidence to venture beyond basic yogurt or sauerkraut to an endless variety of vegetable and/or fruit combinations.