Sourdough bread, yogurt, sauerkraut, kimchi, or kombucha may seem like completely different foods at first glance. However, they all have one thing in common: their production is based on fermentation – a technique that humans were using long before they knew that microorganisms were involved.
Today, fermentation is experiencing a new boom. Sourdough is being started from scratch, kimchi is being pickled at home, and kombucha is being offered in numerous varieties. However, the technique is by no means new. Archaeological finds show that humans were specifically producing fermented foods and beverages thousands of years ago. Some evidence of grain fermentation even dates back more than 10,000 years.
But how was fermentation discovered? Why was it so important to earlier cultures? And how did this lead to foods like yogurt, sourdough, or kimchi that we are still familiar with today?
What actually is fermentation?
During fermentation, microorganisms such as bacteria, yeasts, or molds change the components of a food. This creates new substances that can influence taste, smell, texture, and shelf life, among other things.
A scientific definition frequently used today describes fermented foods as foods produced through desired microbial growth and enzymatic conversions of food components.
That sounds technical – but we encounter this process in our daily lives all the time.
Milk becomes yogurt through specific bacteria. Flour and water become sourdough with the help of yeasts and lactic acid bacteria. During lactic acid fermentation, vegetables develop the typical taste of sauerkraut or kimchi.
Fermentation is therefore less of a single process and more of a collective term for various microbial processes.
How did the fermentation of foods come about?
It is impossible to say with certainty who invented fermentation. It was likely discovered independently in different places.
This is quite understandable: microorganisms occur naturally on plants, grains, fruits, and in our environment. If food is stored under suitable conditions, microbial processes can therefore begin even without consciously added starter cultures.
Early humans did not need to know about yeast cells or lactic acid bacteria for this. They could observe that dough left to sit would rise, milk would become sour and thick, or pickled vegetables would taste different after some time.
The decisive factor thereafter was experience: certain conditions consistently led to a desired result. This knowledge could then be passed on.
Thus, fermentation techniques emerged gradually and were refined over generations.
Fermentation long before refrigerators and tin cans
Today, we can freeze, pasteurize, or transport food under refrigeration. For the vast majority of human history, however, these options were not available.
Fermentation was therefore particularly valuable.
By changing a food item, new flavors could be created, raw materials could be used differently, and certain products could be kept longer. Fermentation was thus simultaneously a processing technique, a craft, and part of regional food culture.
Archaeological evidence shows, for example, that grains may have been used to produce fermented beverages as early as 13,000 years ago. Fermented products such as bread and beer are also known from ancient Egypt.
Fermentation was by no means limited to Europe or the Mediterranean region. Very distinct methods developed on different continents – depending on which foods were available locally.
Sourdough: Fermentation from flour and water
Sourdough is probably one of the best-known examples of traditional fermentation.
The foundation could hardly be simpler: flour and water are mixed together and left to sit for an extended period. Under suitable conditions, a community of yeasts and lactic acid bacteria develops within it.
These microorganisms change the dough. Among other things, yeasts produce carbon dioxide and help the dough rise. Lactic acid bacteria produce acids, thereby shaping the aroma and properties of the sourdough.
Fermented doughs were already being used in ancient Egypt. Historical and archaeological sources show that humans used yeasts for bread production long before these microorganisms could be scientifically described.
The principle has hardly changed to this day: a portion of an active sourdough is kept and continued with new flour and water.
In this way, a fermentation culture can theoretically be maintained for many years.
Yogurt: When milk suddenly became usable for longer
The fermentation of milk also has a long tradition.
Milk offers very good growth conditions for microorganisms. Certain lactic acid bacteria partially convert the lactose it contains into lactic acid. As a result, the pH value drops, the milk becomes more acidic, and its structure changes.
Exactly this principle is behind yogurt and numerous other fermented milk products.
Historically, the fermentation of milk was likely particularly important for cultures that kept animals and transported or stored milk. Depending on the region, very different products emerged from this – from yogurt and kefir to various types of cheese.
What originally arose from observation and experience is now carried out in a controlled manner: modern yogurt production utilizes precisely selected bacterial cultures.
Kimchi: Fermentation as part of Korean food culture
A particularly well-known example of fermented vegetables is kimchi.
Kimchi does not refer to a single recipe. There is a multitude of different variants that can be made from napa cabbage, radish, and other types of vegetables, among others.
During fermentation, lactic acid bacteria in particular multiply. They change the sugar components of the vegetables and, among other things, ensure the characteristic acidic taste.
Historically, the production of fermented vegetable products had a practical advantage: seasonal harvests could be processed and used for longer periods.
Over time, however, it developed into much more than a method for preservation. Kimchi became an integral part of Korean cuisine and shows particularly well how closely fermentation and food culture can be linked.
Kombucha: Fermentation in a beverage
Beverages can also be fermented.
For kombucha, sweetened tea is fermented with the help of a community of different microorganisms. Often, a so-called SCOBY is used for this – a culture of bacteria and yeasts.
During fermentation, the microorganisms change the components of the drink. This produces organic acids as well as small amounts of other fermentation products, among other things.
The exact historical origin of kombucha cannot be reconstructed beyond doubt. The beverage is often associated with East Asian traditions. What is certain, however, is that today kombucha is a good example of how a traditional fermentation technique is being reinterpreted in a modern form.
Fermentation varies worldwide
Kimchi from Korea, yogurt from various regions of Asia and Europe, or sourdough bread show only a small selection.
All over the world, humans have used fermentation to change their respective staple foods.
For example, the following were created:
- Sauerkraut from fermented cabbage
- Miso from fermented soybeans and other ingredients
- Tempeh from soybeans
- Kefir from milk
- Sourdough from grain
- Fermented fish products
- Cheese and fermented milk products
- Vinegar
- Wine and beer
- Various fermented vegetables and beverages
Which form of fermentation developed depended heavily on the climate, available raw materials, and regional traditions.
That is precisely why there is no such thing as "the" fermentation cuisine today.
Why was fermentation so valuable for humans?
The historical significance of fermentation cannot be reduced to a single advantage.
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Food could be preserved differently.
Before refrigerators existed, methods for preservation were particularly important. Together with salt, drying, or cool storage, fermentation could help make food usable for a longer period of time. -
New flavors were created.
Mild cabbage becomes acidic sauerkraut, milk becomes yogurt, and simple dough becomes aromatic sourdough bread. Many flavor profiles that we take for granted today only emerge through fermentation. -
The properties of raw materials change.
Microorganisms break down certain food components during fermentation. This can change consistency, aroma, and composition. -
Fermentation helped to use seasonal raw materials.
Large harvests could be processed instead of having to be consumed exclusively fresh.
Over the millennia, a practical technique thus became an important component of many food cultures.
From experience to microbiology
Throughout most of history, humans did not know why fermentation worked.
They only knew how it worked.
Starters were passed on, vessels were reused, and successful methods were repeated over generations.
It was not until the 19th century that a more precise scientific understanding of the role microorganisms play in fermentation processes developed. The realization that, for example, yeasts are living organisms actively involved in fermentation fundamentally changed the view of traditional production methods.
This marked the transition from empirical fermentation to controlled microbiology.
How does fermentation work today?
The basic idea has remained the same, but control over the process is significantly greater.
In food production today, specifically selected starter cultures can be used. Temperature, time, humidity, oxygen supply, or pH value can be precisely controlled.
This allows manufacturers to reproduce the properties of a product much more reliably.
In addition to classic foods, fermentation has also developed into an important technology in the food industry and biotechnology.
The ancient cultural technique has thus by no means disappeared. It has been scientifically further developed.
Why fermentation is so popular again today
Interestingly, even in a highly technological food world, many people are once again interested in very traditional forms of fermentation.
Sourdough starters are maintained at home, vegetables are fermented by individuals, and products like kimchi or kombucha have long been available outside of their original regions.
There are several reasons for this.
Fermentation combines craftsmanship with a spirit of experimentation. A product visibly changes over several hours or days. At the same time, complex flavor profiles are created that are difficult to replicate with other methods.
Added to this is the growing interest in microorganisms, the gut microbiome, and fermented foods.
However, a distinction is important here: a fermented food does not automatically contain live microorganisms, nor is it automatically a probiotic food. For example, the microorganisms in a sourdough are largely killed off during baking.
Who invented fermentation?
A single person or culture cannot be named as the inventor of fermentation.
It is very likely that various societies discovered fermentative processes independently of one another. Microorganisms occur naturally in our environment, meaning fermentation could take place long before humans understood what was happening at the microbial level.
What was the first fermented food?
This question also cannot be answered definitively.
Archaeological finds point to very early fermented beverages made from grain. At the same time, fruits, milk, and grain porridges likely fermented spontaneously at an early stage as well.
The archaeological evidence known to date therefore shows one thing above all: fermentation has accompanied human nutrition for many thousands of years.
FAQ:
Is sourdough a fermentation?
Yes. Sourdough is created through the activity of microorganisms, especially lactic acid bacteria and yeasts. However, the finished, baked bread usually no longer contains any live fermentation cultures, as they are inactivated by the high temperatures during baking.
Is yogurt fermented?
Yes. In yogurt production, specific lactic acid bacteria convert components of the milk. Yogurt is therefore a classic example of a fermented food.
Are kimchi and kombucha also fermented?
Yes. In the case of kimchi, lactic acid bacteria in particular take on central tasks during fermentation. Kombucha, on the other hand, is created by a community of yeasts and bacteria.
The microorganisms involved and the fermentation paths differ – but the basic principle remains the same: microorganisms specifically change the starting food.
Conclusion: An ancient technique that remains relevant today
Fermentation is one of the oldest forms of food processing. Long before humans could look at microorganisms under a microscope, they learned to use their activity for the production of food.
From this experience, sourdough, yogurt, cheese, fermented vegetables, beverages, and numerous regional specialties emerged.
Today, we understand much more precisely what happens during these processes. At the same time, the basic idea has survived surprisingly well: microorganisms are given suitable conditions – and transform a raw material into something new.
Perhaps it is precisely this combination of millennia-old tradition and modern microbiology that explains why fermentation is receiving so much attention again today.