By Dr. R.S. Stiel, M.D.
Have you ever wondered what gives sourdough bread its unmistakable taste, what gives kimchi this fascinating variety of nuances or what makes kombucha such a multi-layered taste experience? The answer lies in an ancient yet ultra-modern process: fermentation. It has been with us for thousands of years and – carried by invisible microorganisms – opens up a world full of aromatic surprises.
The essence of fermentation
At its core, fermentation describes the targeted conversion of food by microorganisms: Bacteria, yeasts or molds. These tiny helpers release enzymes that fundamentally change the structure and character of our food. From a scientific point of view, fermentation is the process in which microorganisms convert sugar into other substances in the absence of oxygen.
The term “fermentation” is derived from the Latin fervere, which means “to boil”. The Romans observed how grape juice began to bubble in vats as it gradually matured into wine and compared this movement to boiling. In fact, however, no heat was involved – rather, it was the living process in which yeasts transformed the sugar in the grapes into alcohol.
However, not every method that we call fermentation today fits exactly into this chemical definition. Some processes are straightforward, such as koji: a special mold penetrates rice or barley and breaks down their starch into simple sugars – this is called primary fermentation. Others, such as the production of delicious garum sauces, follow on from primary fermentation and use its enzymes to refine animal proteins. Whether primary or secondary fermentation – the principle remains the same: It is the microbes that transform and enrich our food.
Why are fermented foods so irresistible?
Our sense of taste is a sophisticated survival mechanism that instinctively leads us to the foods that are good for us. The palate and nose detect complex chemical signals and send them to our brain: sweet, ripe fruit signals high-energy sugar, while bitter notes can indicate something undesirable.
Fermentation starts precisely with this system: it breaks down large, complex molecules into smaller ones, which our taste perceives much more intensively. Starch in rice, bread or pulses consists of long glucose chains, while proteins in meat and soybeans consist of complex amino acid strands. Of particular note is glutamic acid, an amino acid that registers on our tongue as umami – that deep, savory taste that makes mushrooms, tomatoes or soy sauce so special.
These large molecular chains are barely accessible to our taste buds in their original form. Only fermentation – the key to the variety of flavors – breaks them down: Microorganisms break down starch into simple sugars and proteins into freely available amino acids.
This is how the magic of fermented food unfolds: Koji-fermented rice acquires an impressive sweetness that goes far beyond the taste of cooked rice. Beef refined to garum develops an aromatic depth that appeals directly to our primal instincts.
Fermentation not only makes food more digestible and nutritious – above all, it gives it an incomparable taste. Microbes take over the subtle pre-digestion of complex ingredients and transform them into a true feast for the senses. Over generations, this has developed into a close symbiosis: Today, many of these microorganisms are as strongly adapted to humans as pets. The task of fermenters is to create the ideal conditions for this partnership – and thus lay the foundation for a fascinating taste experience.
