Fermentation is everywhere around us. Bacteria, the enemies of the modern world, are everywhere, in the air, in our bodies, on surfaces. These microscopic elements can transform so many foods and make them delicious or sometimes even disgusting. If we leave one fruit to ripen for a few days we can see its transformation: from fresh and beautiful, to putrid and inedible. Here the fruit stops being an individual and becomes a multitude: that of molds and bacteria. Then there is the opposite process, that of fermentation that brings out the best of food, the umami, the acidity, the tastiness of it. Here the food is transformed into something alive, which can fill and satisfy our taste buds as few foods can do.

Fermentation is a biochemical process, which sees the creation of a favorable environment for the development of bacteria or molds to recreate a simpler and more digestible raw material. Put more simply: it is real magic! There is something about fermentation that transcends exact science: it wants to be integrated into the rhythm of life. This rhythm is irregular, it is rooted in culture, tradition, and habits. Fermentation is so complex and simple at the same time, it is a love story that must be observed in its continuous change, it is a story of waiting, patience, care, and preservation. Its roots go back to ancient times when it was used as a method of preserving food: for example, if milk was leftover, it was transformed into cheese; not to mention the nectar of the gods, wine, king of fermentations. The list could be a very long one: from sauerkraut to kimchi, from pickles to sourdough bread, from beer to miso… so on and so forth. Fermented products, however, have not always been looked on favorably: with the arrival of industrialization of food, its standardization, and the massive controls on food safety, we have also seen the death of centuries-old traditions. We learned to “sterilize” food, leading it to standardization, which then, over time, made us forget the taste of food. Tasting raw milk cheese or eating sourdough bread certainly has an effect and completely different taste from the industrial one. Thus, with time, the benefits of natural fermentation have been lost. Today, however, we are witnessing a return and a desire for those flavors, or perhaps a discovery of those not yet known.

Sandor Ellix Katz tells the journey that brought him and brings him every day into the world of fermentation. His masterpiece, “the art of fermentation”, is more than a cookbook, says Michael Pollan in the preface: it is a way to make people think holistically, to connect man to the world of the invisible, that of bacteria.


1. How does your interest in fermentation arise?

It developed in different stages: as a child raised in New York, I loved pickles. My parents were immigrants from Eastern Europe, so as part of our culture, there were always pickles in our fridge. I knew nothing about fermentation, but for some reason, I was attracted to this specific taste of lactic acid fermentation. Then, in my mid-twenties, I spent a couple of years on a macrobiotic diet: a Japanese inspired diet, popular in the United States. One aspect of this diet is the consumption of fermented food for its digestive benefits. I noticed that every time I ate pickles, I could feel my salivary glands rising more than usual and I began to associate this food, tangibly and variably, with improving my digestion. I started eating them more, but at that time I wasn’t preparing them myself. What stimulated me to learn about fermentation was in 1993, when I moved from New York to Tennessee, where I still live today, and I started keeping a vegetable garden. I was such a naive city kid and never thought about the rhythm of the garden. So, the first year I was gardening when I was faced with the reality of agriculture, and I had such beautiful cabbages, there I decided that I had to learn how to make sauerkraut. I liked their taste and what’s more, I had a practical reason to conserve the crop: that’s when my journey towards fermentation began. I started making sauerkraut, then I started experimenting with other vegetables, making yogurt, making bread with sourdough, and so on. Over time, it developed into an ever-growing obsession and I started to learn more and more. Eventually, I started to be invited to do workshops on fermentation, and finally, teaching led me to write.


2. Fermentation in simple steps

Fermentation is the transformative action of microorganisms. Thanks to the science of microbiology today we know that all plants and animal products that become food are populated by microorganisms: never by a single type, but always by a community of them. Depending on which microorganism grows, different outcomes are possible. Our food can decompose into something disgusting that no one would ever think of putting in the mouth or under certain circumstances a pathogenic organism could cause food poisoning. What characterizes fermentation, on the other hand, is that there is always a practical benefit of microbial transformation: different benefits are thus obtained for different products. In some cases alcohol production, in other longer storage, or improved digestibility, elimination of some toxic elements, improved taste or texture, and so on. For example, the fermentation of milk in cheese makes it more stable and tastier. Or when you think of fresh pork, if you turn it into salami it will keep for much longer. So, in the end, fermentation makes something that might otherwise be very heavy and less digestible, lighter, and more enjoyable to eat.


3. Why ferment, why today?

Well, fermentation is a very important practice of how people everywhere make practical use of the food resources available to them to transform them. Once you start thinking about how the food you like to eat and drink is created by agriculture or the food you can harvest in the forest, then fermentation is part of the answer. I don’t think it is essential that everyone ferments, but I think it is very important that more people are involved in different aspects of food production and become more intimate with the way food is produced and more aware of it.
My goal is to give people information and make them think more broadly so that they can cultivate a greater awareness of how we and microorganisms are interdependent. Think about the action of cutting cabbage into kimchi: it is an opportunity to think about the whole food production. Food is not just a consumption experience, it is information handed down from generations and ancestors. So, my idea about fermentation is to encourage people to broaden their perspectives on it.


4. Why do we like some fermented foods more than others?

Part of the answer is in the familiarity that everyone has with food, for the cultural importance that each country gives to certain foods, on this depends the taste of people. In Italy, people are familiar with raw milk cheeses, salami, natural wines, and so on… but they may not be familiar with sauerkraut or pickles. Fermented vegetables are not common in Italy and throughout Southern Europe and I would say that the main reason is that the further North you go, the shorter the growing season; the longer the winter, the more these foods are essential for survival, so the way to preserve these foods is fermentation.


5. Yesterday and today: What has changed and in what direction will we go?

During the 20th century, with the centralization of food production, people have become increasingly distant from every aspect of food: from agriculture to processing methods. Because of urbanization, the industrial revolution, mass production, and the advent of supermarkets, people have become increasingly distant from the food they eat. In the past there was a decentralized production chain, today there is a centralized one. I think this is a big problem because it makes us increasingly vulnerable and dependent on all production processes. So, it is important to rethink our food production on a smaller, decentralized scale.
We cannot rely on growing the same product in the same places, because it is unsustainable. I, therefore, believe that we will have to try to diversify agriculture more and more.

It is interesting that in this COVID-19 situation so many people have started to ferment, and it makes sense, because now, with more time available, they are getting closer to slower practices: it is an opportunity. I do not necessarily want to draw conclusions about what the outcome of the pandemic will be, but I think there are already great uncertainties in our lives, such as climate change, which will force us to rethink things and the way we produce food.

6. Do you think there are limits to fermentation?

There are limits in terms of time, storage, temperature… but for me, the bigger question is: is there a final number of fermented products, of variations that can be created? Absolutely not. The only limit is imagination. As long as you understand the bacteriological environment of food, you could make sauerkraut with many other ingredients. There are so many fermented foods that I love, and I love their diversity. Part of the emotion is that you can have so many different end products from one main ingredient: think of the milk from which you can make a lot of different cheeses. They have different characters: that’s the magic I love and find exciting.


7. Fermentation and health: health benefits and dangerous foods. What are the benefits?

The conception that fermented food is a danger is imaginary. Traditions would never have survived if fermented food had been dangerous. In the 20th century, it was known that people were afraid of bacteria and projected their anxiety into the fermentation process. Take the example of fermented vegetables: there is not a single case in the history of food poisoning for fermented vegetables.


In terms of health benefits, the world of fermented food is so diverse that it is difficult to generalize, not all fermented foods have the same characteristic. But, in general, the benefits can be divided into:

– Pre-digestion: the idea that nutrients can break down into simpler forms. For example, if you try to eat a soybean simply cooked you will feel intestinal gas, but if you ferment the soybeans, the proteins are reduced to amino acids and the nutrients become much more available.

– Detoxification: It is the same process, but instead of breaking down the nutrient compound, it breaks down the potentially toxic compound. For example, cassava: in some cases, if people try to eat it raw, it kills them, but if you ferment it, the toxic compound breaks down.

– Nutrient enhancement: Fermentation creates more nutrients. For example, almost all fermented foods have a high level of B vitamins.

– Bacterial cultures: The potential benefits are the bacteria themselves. The current thinking in evolutionary biology is that all life is descended from bacteria. They provide essential services for us: in the case of our body, digestion requires the participation of bacteria. We increasingly recognize that our immune system is the work of bacteria. The game-changer is that there has been great recognition that the chemistry of our brain is regulated by the bacteria in our intestines. Of all these factors, some have to do with what we eat: less and less fiber, less food rich in bacteria, or more exposed to chemicals or antibiotics that decrease bacteria in the intestines. Potentially the greatest benefit of this food is to help restore biodiversity in the gut. So, I think anyone can benefit from it, especially to improve digestion. But we have to understand that the benefits are general and different from person to person.


Lodovica Bo