October 19, 2016

They’re Alive! Fermented Food Part 1

Fermentation is in—though the process of fermenting food isn’t exactly a new one. Cultures around the world have crafted unique traditions and flavors around fermented foods for thousands of years, from Korean kimchi to German sauerkraut to Indian chutneys and everything in between. Many of our favorite everyday foods like bread, cheese, beer, wine, and yogurt are also the result of fermentation.

While many fermented foods have been largely lost with the industrialization of our food system, there is a growing movement to resurrect this ancient practice. So whether you’re interested in preserving culinary tradition, gaining purported health benefits, or simply trying new foods and flavors, here’s a primer of everything you need to know to jump on the fermentation bandwagon.


What is fermented food?


Simply put, according to Sandor Katz, James Beard-award winning author of The Art of Fermentation, fermented foods are “the flavorful space between fresh and rotten.” While this may not sound too appealing, it beautifully captures the essence of fermented foods. Fermentation occurs when microscopic organisms, namely bacteria or yeast, feed on the sugar and starch present in foods to create alcohol, acids, and/or gases. For instance, yeast fermentation turns grapes into wine and grains into beer or into carbon dioxide to leaven bread.

fermented foods kimchi

A tried-and-true preservation technology


Not as obvious, but vitally important and beneficial, are the products of bacterial fermentation, a process whereby lactic acid bacteria convert the sugar in vegetables, fruits, and dairy products into lactic acid and carbon dioxide without the need for oxygen. Known as “lacto-fermentation,” this process creates conditions that prevent the growth of pathogenic microorganisms and breaks down the food into a more digestible form, while preserving and enhancing its nutritional quality. According to the Food and Agriculture Organization of the United Nations, fermentation is one of the oldest forms of food preservation technologies in the world, and fermented foods are critically important in meeting the nutritional requirements of a large portion of the world’s population.


Probiotic powerhouses: the health benefits


In addition to increasing the shelf life of foods and protecting against foodborne illness by inhibiting growth of certain pathogens, naturally fermented foods have been shown to support human health in various ways. Compared to many factory-processed staples of the standard American diet, fermented foods are literally alive and teeming with “good” bacteria and enzymes that aid in digestion and the growth of beneficial microorganisms in our guts, i.e., probiotics, probiotics, probiotics.


An exciting and growing body of scientific research indicates that probiotic powerhouses such as fermented foods may help heal a multitude of gastrointestinal health issues and can even lead to weight loss and improved immunity. The National Institutes of Health-sponsored Human Microbiome Project, in its quest to characterize all the microorganisms living within the human body, is telling us more about how our unique strains of bacteria may impact our individual health and disease risk. Or, as Sandor Katz explains, “Our bacteria perform all sorts of essential functions for us, and because we are continually attacking them effectively with all of these chemicals in our lives, simply replenishing and diversifying these populations has a benefit for us.”


One of the main theories of integrative medicine is that digestive dysfunction is at the root of most health issues, so a common strategy used by physicians and dietitians in this field is to rebalance one’s intestinal flora using a “food-first” approach that includes naturally fermented foods. While the emerging body of evidence on the health benefits of probiotics is promising, specific benefits of probiotic foods depend on the particular strain of bacteria or yeasts, so exactly which strains and appropriate dosages are still being studied. Adding to the complexity of studying fermented foods—especially those traditionally produced on a small scale—is the enormous variation in microbial profiles across different sources. But this is why making fermented foods is a truly artisanal craft, and one that can contribute to improving our microbial biodiversity if we consume a variety of these foods.


More to come in Part 2

In Fermented Foods, Part 2, you’ll discover some common fermented foods and find out how to incorporate more of them into your diet. Plus, a recipe for our tasty turnip kraut!

By Allison Righter, MSPH, RD

Allison Righter is a Registered Dietitian Nutritionist and lecturing instructor of nutrition and food safety in the Culinary Science Department at the CIA.