When friends stop by my place for a visit, they often comment on the jewel-like jars of vegetables gently bubbling on my kitchen counter. It looks to them like some sort of intriguing science experiment; they call it my "food of the future."
Actually, it's food of the past: traditional Korean kimchi. The tangy vegetable dish is one of several fermented foods (others include sauerkraut, miso, tempeh, and yogurt) that scientists have recently declared nutritional blockbusters. Loaded with cancer-fighting nutrients and antibacterial and antiviral properties, many varieties of fermented foods aid in digestion and can help treat ulcerative colitis, yeast infections, and possibly avian flu.
Although the word preservative has a bad rap today, it dates to the time humans needed to preserve a stable food supply. Ancient peoples discovered that by storing foods in salty brine or inoculating them with live cultures, they were able to keep them clean and edible longer. This process, known as lactofermentation, causes the sugars in food to be "digested" by a bacterium called lactobacillus, creating lactic acid and effectively shielding the food from putrefying bacteria and other pathogens. "The history of lacto-fermentation probably goes back 6,000 years, to ancient China," says Nina Etkin, professor of anthropology at the University of Hawaii and author of Edible Medicines: An Ethnopharmacology of Food (University of Arizona Press, 2006). The Chinese developed a broad range of pickled foods-including cabbage, meats, and the original soy sauce-and the process was disseminated through trade with the rest of Asia and Europe.
"The Chinese have a saying: Medicine and food are of one source," reports Miles C. Chen, Ph.D., founder and director of the Chi Wellness Clinics in Boston. "I suspect the health benefits of fermentation were discovered shortly after its preservative power was." Indeed, the growth of lactobacilli not only preserves food but actually causes beneficial microorganisms, or probiotics, to multiply. As sugars are digested and lactic acid is created, vitamins and other nutritious substances are generated. The life cycle of lactobacilli produces cancerfighting, antioxidant-rich nutrients, including B vitamins and vitamin K. It also preserves fragile vitamins, such as vitamin C, that might otherwise be lost in conventional long-term storage. In addition to health benefits, the power of kimchi, sauerkraut, miso, and other fermented foods as a digestive aid is legendary. "Fermentation can be thought of as a kind of predigestion," suggests Bill Mollison, author of The Permaculture Book of Ferment & Human Nutrition (Ten Speed Press, 1997). The process neutralizes phytic and oxalic acids, which can hinder absorption of nutrients, and creates its own enzymes. Those enzymes can be an effective means of digesting even such problem foods as lactose (lactoseintolerant people can usually digest lacto-fermented yogurt comfortably) and soybeans (miso and tempeh, both fermented varieties of soy, do not cause stomach gas the way ordinary soybeans often can). Even in rural Minnesota, my Korean parents insisted on eating kimchi with every meal. My father, a doctor, maintained he needed it for his digestion and health-and he never took a sick day in his more than 40 years of work.
But fermented foods aren't just good for you; they're also delicious. Scott Simons, host of The Secret Ingredient online cooking show, describes their flavor as "distinctly different from other tart flavors like citrus or vinegar-an almost effervescent mouthfeel." Chef Charlie Trotter, whose eponymous Chicago restaurant is world-renowned, enthusiastically includes a variety of fermented ingredients in his dishes and predicts, "It won't be long before all serious chefs and home cooks will understand how to prepare this raw and living food."
I am not a terribly sophisticated cook, but for years I have made my own organic kimchi and sauerkraut- after I got over my fear of leaving food out on the counter to ferment for days or even weeks. "If you're strictly following the recipes using clean, fresh foods and washing hands, dishes, and countertops, you're not likely to encounter problems," says Jason Tor, Ph.D., a microbiologist who teaches a Kitchen Ecology course at Hampshire College in Amherst, Mass. (For the record, Tor has eaten what he considered a "perfectly delicious" miso that was more than 15 years old.) Fermentation enthusiast Sandor Katz, author of The Revolution Will Not Be Microwaved: Inside America's Underground Food Movement (Chelsea Green, 2006), notes, "It's only in the past century that fermentation disappeared behind factory doors. Reviving those practices is a way of reclaiming control of your food."
Fermented foods are living things and should be treated with care. When purchasing them at specialty food stores or ethnic markets, you should find them in the refrigerated section, and the package should read "live active cultures." (Pasteurized sauerkraut and pickles, for instance, contain no live cultures.) Sandor Katz shares some of his favorite fermented food recipes, developed with the home cook in mind. Enjoy this ancient culinary tradition, whose powerful nutritional content may protect you from some very modern ills.