August 11, 2015 at 8:18 pm

Sandor Katz on A&S TV: Fermentation Is Culture Bubbling Over

By Lori Price

Sandor Katz called himself a food activist and a fermentation revivalist at the Food for Thought seminar  at Ohio University.

“This is an incredibly important category of food and beverages, since everybody in the entire world eats or drinks things that have been fermented every single day,” he explained on April 2, 2015 on A&S TV.

“We don’t know the origins of any fermented foods or drinks because they are all so ancient,” Katz said. He clarified that the word “fermentation” comes from the Latin root word fervere, which means to boil or to seethe, a reference to the bubbles of gas byproduct created during the process of fermentation. This ancient practice was most likely retained due to the fact that it enabled primitive people to ensure a more healthy, palatable, available food source for themselves throughout the year.

He questioned the audience regarding how many had consumed fermented foods that day. However after he provided an extensive list of common foods that most people do not know are fermented or based on fermented products, he repeated the question to find that a significant majority of the audience had, indeed, consumed fermented foods and continue to do so daily. Some of these foods included obvious items such as pickles and sauerkraut, but also many surprising ones such as coffee, bread, cheese, cured meats, chocolate, vanilla, some styles of tea, many condiments and sauces, and several other commonly eaten items.

‘Fermentation Is Not Rocket Science!’

“What these foods have in common is that they were processed or prepared by the action of microorganisms.” Katz explained his preferred definition of fermentation, “A working lay definition of fermentation is that it is the transformative action of microorganisms.”

He went on to mention that in modern times, bacteria are viewed with suspicion. As the outsourcing of food production took place and commercial agricultural food production took precedence over production by individuals at home in private gardens, people have become increasingly fearful that bacteria are dangerous, bringing potential illness and death to any who would inadvertently or intentionally consume them. In recent years, the public has become willing to leave the study and utilization of bacteria to food science researchers behind factory doors rather than rely on traditional wisdom and practices.

Katz debunks this idea of leaving the bacteria to the specialists. “Fermentation is not rocket science!” he proclaims. “Because we now have a better understanding of microorganisms, and it is easier for us than ever before to be able to control heating and cooling of our food and beverages, individuals are perfectly capable of making our own healthy, tasty, safe fermented products.”

Fermentation is the result of anaerobic microbial processes, although a handful of products do require oxygen in order to ferment. Katz jokingly refers to them as “oxymoronic” foods. They include tea, which transforms into kombucha, alcoholic beverages which become vinegars, milk which transforms into some cheeses, and soybeans which are transformed into tempeh. This makes it difficult to fit those products into a traditional biologist’s definition of fermentation, which means strictly the production of energy without oxygen, also known as anaerobic metabolism.

Katz acknowledges that this transformative action of microorganisms is not always a good thing, as it can sometimes result in spoilage or rotted foods. However, in these cases, fermentation usually is not used to describe the process.

“It is an inevitable fact that that all of the products we consume are certainly populated by complex colonies of microorganisms. All of the plants and all of the animal products that make up our food contain these elaborate communities of microorganisms. The difference between a disgusting, rotten food and one that is fermented to perfection is mostly about which kinds of microorganisms are growing most predominantly on the food.”

“We have gained tremendous insight since the work of Louis Pasteur. It may surprise many people to learn that the cells of our bodies are outnumbered by a factor of 10 to one by the bacteria to which we play host. They are not parasites – they do not make us sick – we coexist with them perfectly well and in many cases they provide all sorts of essential services to us, giving us a lot of our functionality.”

Sandor Katz meets with Ohio University students and Athens fermenters.

Sandor Katz meets with Ohio University students and Athens fermenters.

‘We Actually Need Bacteria’

Katz went on to say that, “This is one of the reasons for heightened interest in fermentation and microbially rich foods right now because after a lifetime of war on bacteria, a lifetime of hearing how dangerous bacteria are, the more nuanced notion is developing that we actually need bacteria.” Beneficial bacteria in the human body are now known to be critical in the process of digestion, to aid in the performance of the immune system, and to play an important role in neurological function and brain chemistry.

Katz explained that, “Serotonin, dopamine and other chemical compounds that help determine how we think and how we feel are regulated by the bacteria in our guts.” He adds that, “ Really, every aspect of our physiology and functionality is related to these bacteria that were regarded as dangerous enemies until pretty much the 21st century.”

He cautions that not all fermented foods are microbially rich – that depends on what happens after fermentation. For example, a can of sauerkraut may well have been bursting with beneficial microbes when it was initially fermented, however those organism are usually killed during heat exposure during the canning process. Another example is sourdough bread, which has abundant levels of microbes in the dough but they perish during the baking process.

Katz said that the subset of fermented foods that have not been heated or frozen and have their microbial communities intact when we eat them is known as probiotic products and can help to rebuild the microbial biodiversity in the gut when eaten. He admitted that he finds it ironic that fermentation is on the 2015 list of current food trends. “Fermentation is an ancient practice and a staple of our existence, it is not a fad. The new trend is awareness of the importance of fermentation, not the idea of fermentation itself.”

“After several generations of the full-on embrace of convenience foods, of people being thrilled with one-stop shopping and being able to buy foods at least partially prepared beforehand, people are now realizing such food is nutritionally diminished, and we are seeing all of these nutrition-related health epidemics developing,” he said. “Due to concerns over the health impacts of modern convenience foods, the environmental impact of modern agricultural methods, and the economic impact of removing food production from local communities, people are paying a lot more attention to food now.”

Katz said that looking back, although no one knows for sure, it appears that the earliest intentional practice of fermentation probably resulted from the accidental realization that as simple sugars were allowed to sit, they were transformed into alcohol. “Fermentation was not invented, it is simply a natural phenomenon. Since we evolved with the enzymes to digest alcohol, that suggests that it is something that was present in our evolutionary past and our evolutionary forbearers were at least periodically familiar with it.” He added that the next steps were the technology to fashion vessels that would contain liquids, including fermented or fermenting beverages.


Claude Lévy-Strauss, French anthropologist and cultural theorist saw making alcohol as the original act of culture. He believed that it was fermentation that made the practice of agriculture possible. It was a critically necessary response to the problem of how people could invest a large percentage of their energy on growing crops that would ripen only at one time during the year and which would have a limited period of usefulness unless preserved. Fermentation provided a strategy for making the crops edible and nourishing for a much longer period of the year, often through to the next harvest.

Katz pointed out that while preservation of the harvest is a significant benefit of fermentation, another benefit is that of enhanced digestibility. He feels that the increasing incidence of gluten intolerance might be related to the use of only one strain of yeast in modern, commercial bread making. “Prior to commercial bread production, it was not one kind of yeast, but elaborate communities of multiple kinds of bacteria, in addition to the yeast, that leavened the bread. And when you ferment wheat with bacteria, it breaks down the gluten.”

In addition to harvest preservation and enhanced digestibility, fermentation also facilitates nutrient assimilation and detoxification in certain foods such as cassava. He also explained that fermentation creates strong flavors that many people enjoy and seek out. He gave examples such as sweet potatoes and olives as foods that improve in flavor after they are allowed to ferment.

Fermentation also affects texture. “If bread wasn’t fermented, it would be like a brick!” Katz said. And many condiments and sauces are either fermented themselves or rely heavily on vinegar for flavor.

…and Beer

Katz then turned the discussion to the popular topic of fermentation and the production of beer. He explained that the basic process was to malt grain and then roast it to stop the malting, make a mash, boil the wort, and then introduce a starter yeast to initiate the fermentation process. “In some cultures, they used the amylase in human saliva to break down the starches. We are more familiar with using malting to break down the starches. And in Asia it is typical to use molds, like aspergillus, to break down the starches.”

Although one strain of yeast is used in commercial beer making, in the past and still in a few areas of the modern world, natural, wild yeasts are allowed to trigger the fermentation process of the beer. He gave the example of the brewing process in Belgium’s Lambic region, where wild yeasts are the primary fermentation ingredient and are allowed to land on the wort in open vats called coolships to begin fermentation.

In concluding his presentation, Katz took a moment to explore the political and intellectual meaning of the term, fermentation. “It goes back to how fermentation works. As the starches ferment, small gas bubbles are often released that gather on the surface. When a concept is said to ferment, that means it is gaining in interest and enthusiasm, it is bubbling up. I like to think of fermentation as an engine of social change, a starter culture of ideas that rise, and as that can be shared with others as they continue to bubble and build in intensity and volume. I hope that the concept of fermentation will ferment within my audience.”

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