Long before refrigeration, people across cultures discovered that fermentation could preserve ingredients while transforming their taste and texture. From pickled vegetables to aged cheeses and sourdough bread, fermented foods are now celebrated not just for their practicality but for their depth of flavour and complexity.
What are fermented foods?
Fermented foods are products that have undergone a natural transformation caused by microorganisms such as bacteria, yeasts or moulds. These beneficial microbes consume the sugars and starches in the food, producing acids or alcohol that enhance flavour, preserve freshness and often improve digestibility. Everyday fermented foods include yoghurt, kimchi, miso, kombucha, sauerkraut and sourdough bread – all examples of how simple ingredients can be elevated through microbial activity.
The process doesn’t only create tangy and savoury notes; it also increases the bioavailability of nutrients. For instance, the fermentation of milk leads to lactic acid formation, which gives yoghurt its creamy texture and pleasant acidity, while also making it easier to digest.
What is fermentation and how does it work?
Fermentation occurs when microorganisms metabolise carbohydrates in the absence of oxygen, producing compounds such as lactic acid, ethanol or acetic acid. Each type of fermentation brings distinct flavours, aromas and textures, depending on the ingredients and the environmental conditions.
Lactic acid vs alcoholic fermentation
Lactic acid fermentation is one of the most common types, responsible for many of the world’s best-loved foods – from sauerkraut and kimchi to yoghurt and fermented beets. In this process, lactic acid bacteria convert sugars into lactic acid, lowering the pH and creating a pleasantly sour flavour that also inhibits spoilage.
Alcoholic fermentation, by contrast, is carried out by yeasts that transform sugars into alcohol and carbon dioxide. It’s the key process behind wine, beer and bread. While these products vary greatly, the underlying principle remains the same: microorganisms generate new flavours and aromas through controlled transformation.
Wild vs controlled fermentation
In wild fermentation, naturally occurring microbes present on the food or in the environment drive the process, as in traditional sauerkraut or sourdough starters. This method produces unique, sometimes unpredictable results that reflect local conditions – the 'terroir' of fermentation.
Controlled fermentation uses specific cultures of bacteria or yeast, ensuring consistency and safety. Modern chefs and food producers often rely on controlled fermentation when precision is essential, especially for fermented dairy or meat products.
Examples of fermented foods from around the world
European classics
Europe’s culinary heritage is rich with fermented staples. Sauerkraut, kefir, yoghurt, sourdough and cheese are among the continent’s best-known examples. In Northern and Eastern Europe, fermented beets are a traditional ingredient, adding colour and tang to soups such as borscht or to refined salads served in modern restaurants. In Southern Europe, olives, wine and fermented sausages showcase how fermentation has shaped everyday eating habits.
Asian staples
Across Asia, fermentation is a cornerstone of gastronomy. Japan’s miso, soy sauce and sake, Korea’s kimchi, China’s fermented tofu and Indonesia’s tempeh all rely on microbial processes that bring umami depth and character. These foods have moved far beyond their origins – today, fermented soy sauces and rice vinegars appear on fine-dining menus around the world, valued for their balance and complexity.
Other global traditions
In Latin America, fermented maize is used to prepare drinks like chicha or pozol, while in Africa, cassava and millet undergo fermentation for staples such as garri and injera. In the Middle East, preserved lemons and laban (fermented milk) are everyday fermented foods that reflect centuries of culinary wisdom. Each culture has developed its own techniques to coax flavour and nourishment from humble ingredients.
How to use fermented foods in refined cuisine
Fermented foods have become a hallmark of contemporary fine dining. Their acidity, umami and layered aromas allow chefs to play with contrast, texture and flavour balance.
Plating and pairings
In refined cuisine, fermented elements are often used to cut through richness or introduce a subtle tang. A dollop of fermented beet purée can brighten a roasted duck dish, while a touch of miso enhances depth in vegetable broths. Pairing is key: fermented foods work beautifully with fatty meats, root vegetables, seafood and dairy-based sauces.
Fermented condiments and sauces
Chefs increasingly craft their own fermented condiments – garums, kombuchas, pickled oils and lacto-fermented purees – to add a personal signature to their dishes. A few drops of fermented chilli sauce or soy reduction can elevate a plate without overwhelming it. In haute cuisine, milk fermentation has inspired creative reinterpretations of yoghurt and kefir, bringing both flavour and texture contrast to desserts or savoury plates.
Tips for fermenting food at home
Fermentation at home can be surprisingly simple and rewarding. Start with vegetables such as cabbage, carrots or beets, which ferment easily with just salt and water. Always use sterilised jars, maintain a clean workspace and keep your produce submerged in brine to prevent mould.
Temperature control is essential – most lactic acid fermentations thrive around 18–22°C. Taste regularly to follow the evolution of flavours – a good ferment should smell pleasantly sour, not rotten. Once you’re satisfied with the flavour, transfer the jar to the fridge to slow down fermentation.
With a little care and curiosity, anyone can experience the magic of transformation that has fascinated cooks for centuries. From everyday fermented foods like yoghurt and kimchi to refined creations in Michelin-starred kitchens, fermentation remains one of the most delicious and creative expressions of culinary art.
