Fermentation—an old method with a new lease of life

14. July 2025

Whether it’s kimchi, miso, Kikkoman Soy Sauce or good old sauerkraut, fermented foods are—literally—on everyone’s lips right now. Jars of pickled vegetables are appearing more and more often on supermarket shelves. And in the catering industry, too, fermented foods are growing in popularity. No wonder—their distinctive tangy flavour adds a special touch to all kinds of dishes.

But fermentation is far from new. People have used this method for thousands of years to make food last. In many Asian countries, it’s also deeply rooted in culinary tradition, with recipes passed down from generation to generation.

And here in Europe? Fermentation is more widespread in daily life than you might expect: black tea, kombucha, sourdough, cheese—and our very own Kikkoman soy sauces—all rely on fermentation to develop their flavour.

But how exactly does this process work, and how can it be used effectively in professional kitchens?

How does fermentation work?

Fermentation is a natural process in which sugars and other carbohydrates in food are converted by micro-organisms—such as bacteria, yeasts or moulds—into alcohol, acids or gases. The whole process takes place in several steps, which may vary slightly depending on the type of fermentation, but are essentially the same.

Fermentation: Step by step

For fermentation to take place, the food must contain sugar or starch—such as in milk, vegetables or grains.
Micro-organisms then come into play. These may be added—like yeast in dough or lactic acid bacteria in yoghurt—or already present in the food itself, such as the natural bacteria in raw cabbage that later becomes sauerkraut.
The food is then placed in a container that allows gases to escape but keeps out contaminants like dust or airborne bacteria. This gives the micro-organisms the right conditions to multiply undisturbed. Modern preserving jars often have special valve systems that release pressure even when the container is tightly sealed.
Once the micro-organisms have multiplied sufficiently, they begin to feed on the sugars in the food—transforming them into lactic acid, alcohol or carbon dioxide.
These by-products are what give fermented foods their distinctive flavour and aroma. They often smell and taste slightly sour or with a hint of alcohol.
The newly formed substances lower the pH value, creating an acidic environment that inhibits harmful bacteria and mould. This extends the shelf life of the food in a natural way.

And that’s not all—fermented foods are often not only delicious but also easier to digest and sometimes even healthier.

Fermentation: not just tasty, but healthy too

The typical tangy taste of fermented foods is a sign that micro-organisms have been at work—and that brings health benefits. Fermentation acts like a natural ‘pre-digestion’, where the micro-organisms break down food in ways that help our bodies absorb it more easily. Studies also show that fermented foods can promote gut health and help ward off harmful bacteria.

Yoghurt is made through fermentation and contains beneficial bacterial cultures that support gut flora.

But it’s not just your gut that benefits: the fermentation process can also make the proteins and vitamins in food easier for the body to absorb—and may even increase the concentration of vitamins B and C, iron and zinc.

Fermented foods also contain probiotic bacteria, which can boost the immune system and may help prevent digestive issues.

Fermenting at home: here's how

Fermenting your own food is easier than you might think. In the catering industry in particular, fermentation opens up exciting ways to intensify flavours, preserve seasonal ingredients and expand your menu creatively. If you'd like to try it yourself—whether at home or in a professional kitchen—just follow these steps and bring a little patience.

Fermentation in a few easy steps

Prepare your vegetables: Wash them thoroughly. If you're using organic veg, you can leave the skin on—otherwise, peel them. Choose firm vegetables, as soft ones tend to go mushy during fermentation and can end up unappetising.
Slice them: Cut the vegetables into pieces that fit easily into your preserving jar.
Salt them: Mix the vegetables generously with salt. A good rule of thumb is about 2% salt to vegetable weight—it draws moisture from the vegetables, creating brine after a while.
Jar them: Pack the salted veg and any brine tightly into a clean preserving jar, pressing down well to remove as much air as possible.
Weigh them down: Use a weight or fermentation stone to keep the veg fully submerged in the brine.
Wait: Seal the jar loosely or use a special fermentation lid. Store it at room temperature and give it a few days to several weeks to develop—depending on the vegetables and your preferred flavour.

Important: Check regularly for any signs of mould or a film forming on the surface during the fermentation process. Minor impurities can often be removed, but when in doubt, cleanliness and hygiene are essential for a safe result—so always wash your containers thoroughly before filling them.

After just a short time, you'll notice how the flavour and texture of the vegetables start to change. Try out different veg and spices to develop your own combinations. In many cultures, fermented vegetables are traditionally enhanced with aromatic herbs and spices—for example, dill with cucumbers in Eastern Europe, ginger and garlic with Chinese cabbage in Korea, or turmeric and mustard seeds with cauliflower in India. Today, fermented foods are finding their way onto our plates in all kinds of forms—and there’s more room for them than ever in modern cooking.

[Translate to Englisch (EU):] Kimchi is a popular fermented cabbage dish in Korean cuisine that's eaten with practically everything.

Using fermentation in your dishes

Fermentation takes many forms, which means there are countless ways to incorporate fermented ingredients into professional kitchens. Here are just a few ideas—but your creativity is the only limit!

As a side dish

Kimchi—Korea’s iconic fermented cabbage—pairs perfectly with rice, noodles or vegetable stir-fries, adding a tangy, spicy depth to the dish.

In soups and sauces

Japanese miso pastes or Kikkoman Soy Sauce are excellent for enriching soups with extra umami. In meat-free dishes especially, the umami boost adds an extra layer of flavour.

In baking

With sourdough, the natural fermentation process produces a loaf that’s aromatic, crisp, and easy to digest, with a pleasantly sour note.

In fusion cuisine

Fermented vegetables are often used as toppings in modern kitchens—for burgers, sandwiches or salads. They not only add an interesting flavour contrast but also make the dish more visually appealing.

The game changer: fermentation

Fermentation is much more than a food trend—it's an age-old technique with huge potential for today’s catering industry. Whether as a spicy side dish, a natural umami enhancer or a creative topping, fermented foods add depth, complexity and nutritional value to any dish.

With a little know-how and a willingness to experiment, this time-honoured method can easily become part of everyday kitchen life—both at home and in professional food service. Why not give it a try and add some fresh excitement to your menu?