Are Fermented Foods “Healthy” and “Natural”?

Yuichiro Murai

September 11, 2022

Last October, American food professionals visited fermented food producers to deepen their knowledge of Japanese fermentation culture during the “Hakko Tourism in Japan” tour campaign. As part of the tour, organizers held a tasting session where guests gave candid advice from the perspective of the American market to food product manufacturers looking to enter the United States market.

Hi my name is Yuichiro Murai. I am the 29th owner of Kojiya-Sanzaemon, a koji manufacturer.

“Fermentation” is a word that is easily associated with the concepts of “healthy” and “natural.” I want to explore these two aspects of fermentation with you today.

Fermented foods are known to bring many health benefits. This has supported the current trend of fermented foods as healthy foods, and I appreciate the well-deserved attention they are receiving.

The perspective of “health” is something that men and women of all ages have in common. Frankly, focusing on the healthy aspects of fermented foods can be a good marketing strategy.

On the other hand, if too much attention is paid to “health” and the “benefits” rather than the fermented foods themselves, the logic can be flipped and we can end up with people seeking the benefits as the main purpose and eating fermented foods could become secondary as just one of the ways to achieve this benefit. In this case, maximizing the benefit is what matters and not the how which is eating fermented foods.

If the main purpose is “eating fermented foods,” you can also enjoy cooking fermented foods, the conversation among those you eat with, and the richness of the heart that comes from thinking about the producers of soybeans, wheat and rice. If you tell me that “the entire experience of eating fermented foods makes me happy”, I think the purpose of eating fermented foods has been achieved.

However, if the goal is to “maximize the benefit or the effect of a particular substance,” then different set of factors become more important such as the temperature for maximizing a certain effect, when to eat, the pairing of foods, and so on. It is as if “fermented food” had turned into “medicine” somehow.

Narrowing down “eating fermented foods” into “ingestion of substance A”, I am going to call this “medicinalization” of fermented foods. I am concerned about the excessive medicinalization of fermented foods. If the end goal is to efficiently ingest active substances, I am afraid that the pure enjoyment of eating in itself will be lost.

Next, let’s look at the concept of “natural” in fermented foods. In fermentation, we have two words, “natural bacteria” and “pure cultured bacteria”, which are actually polar opposites. Seed koji, which is a product of culturing aspergillus, is sometimes called “pure cultured bacterium” as opposed to “natural bacteria”.

So, in this first article, I’d like to explore what it means to be “natural.”

Let’s take a look at the word “evolution.” We often see the expressions such as “evolution of technology” and “progress of values,” but in terms of evolution and progress, I feel that there is a connotation around this terminology that something new is better than the old, in essence, “if not the latest and greatest, it’s wrong.”

In terms of koji mold, “natural bacteria” became a “friend species,” and then it became “seed koji,” then finally “natural mold”. If you consider this process to be “evolution,” everything except the last one is deemed “incorrect.”

Instead of calling this process “evolution of technology,” I wonder if we can accept that we have more technological options now, without invalidating all of the other methods.

Based on the risks and benefits as well as the values of each individual, we can then select the option that is most suitable. I feel that such a way of thinking is more appropriate for the era of versatility that we live in now.

Taking all of this into account, I recommend the use of seed koji in many koji-making cases.

Gut microbiota modulation

Aspergillus oryzae itself is a microorganism that is thought to have been established as a species due to some form of human interference after humans appeared on the earth. In that sense, does “natural fermented food” exist in the first place?

Let’s look at another example. Compare a tree branch dam made by a beaver with a concrete dam made by a human. Concrete is actually made of sand, water, and other natural things. But we would consider dams made by beavers from tree branches as “natural,” and concrete dams made by humans as “unnatural.” If we replace the word “unnatural” with the word “artificial,” why do we consider only humans (homo sapiens) to be a concept separated from “nature”?

We, humans, were originally a part of nature. A group of mammals evolved within vertebrates, then primates, and evenutally a species called Homo sapiens were born. In other words, humans originated from nature. If something was made by humans born from “nature,” it should be considered to be “from nature” and “natural”, whether it is a building made of concrete,  an exhaust gas or an additive, just like a dam made by a beaver or a nest made by a bird.

Some may think that is an outrageous argument. Actually, I think there are many people that think like that. So why do they think that it is outrageous? I think there are feelings of fear and respect for things that humans cannot control, and I want to respect that.

Having said that, what is the difference between the beaver’s twig dam and the concrete dam created by homo sapiens? Where do you draw the line and how should we recognize the world? By becoming aware of it, I realize that there is more than one way to draw the line. And by realizing that each person has various ways of drawing their own boundaries, and that there is no right or wrong answer,  we can escape from the norm of thinking that a certain thing “must be like this” and “should be like this.” 

Some people refer to nature before the advent of humankind as the “original nature,” some refer to the primitive age as the “original nature,” and some refer to the Edo period as the “original nature.” Others might call “original nature” the period before humans invented steam engines,  the time when they were born, or perhaps even the earth in 2021 to be “original nature.”

Gut microbiota modulation

I think it is okay to have different ways of thinking. We, human beings, can experience the diverse ways of nature and people because each person considers something different to be “original” across a wide variet and act accordingly in their own way. That is why I would like to express my sincere respect to those who are working to protect the “original nature” that they believe in.

Bringing the topic back to fermentation, I think that noticing the diversity of differences will lead to an understanding of the difference between “naturally inhibited mold” and “seed mold,” and eventually to understanding terroir. Let’s get perplexed, think about it, and become aware of your border lines, and raise your own resolution together.

By the way, I have looked at “fermentation” through the two keywords “healthy” and “natural.” What these can be said to have in common is that both are words that are easily drawn to be “correct” and tend to be bound by search for the correct answer.

There are various approaches to fermented foods. “Healthy” and “Natural” are just one aspect, and I would like to see more attention from a wide range of angles, such as emotional value and cultural value.

Personally, I want to enjoy the culture of “fermentation” in a more relaxed and deeper way. I want to reach whatever lies beyond. Decoupling the “correctness” and the way it ought to be from fermented foods and creating a culture where you can enjoy fermentation with a richer approach, this is what I want to do. 

Bio'c Co., Ltd. | + posts

Yuichiro Murai is the president of Bio'c Co., Ltd and the 29th Chairman of Kojiya Sanzaemon, specializing in koji mold research and development. With his expertise in biotechnology, Murai is an influential figure in the field of fermentation and koji mold.