When I was a little girl, I remember how our family ate sauerkraut in the winter, because we knew that all vitamins were preserved in it, unlike other vegetables, which had lost most of them by that time. Another reason was that fermented foods literally keep you warm in cold winters.
As I grew up, I fell in love with Indian idli and lassi, Italian olives, French cheese and Japanese miso pasta. All of them are categorized as fermented foods.
All culinary traditions value many varieties of fermented foods, such as kimchi, kombucha, miso, sauerkraut and kefir. They have been known for centuries but are now flourishing again.
In fact, fermented foods have been a trend not only in recent years, but for a whole decade. In the early 2010s, almost all of the top chefs talked about their interest in fermentation. An example is Danish two-Michelin star Rene Redzepi, whose Copenhagen restaurant Noma has been voted the world’s best restaurant four times. It was there that Redzepi equipped an entire fermentation laboratory and hired a staff of chemists. As a result of his research, he published the book The Noma Fermentation Guide. Another example is renowned American chef and restaurant tycoon David Chang, who invented a new product called hozon, made from fermented nuts, grains and seeds. Chang spoke about his experiences studying fermentation in public lectures at Harvard.
What is fermentation?
Fermentation means that the sugars and carbohydrates present in food have been eaten by beneficial bacteria (often lactic acid bacteria), converting them into other substances such as acids, carbon dioxide, and alcohol. These substances ultimately preserve the food (and add flavor to it). So, when you eat, say, sauerkraut, you are consuming a thriving colony of beneficial bacteria.
The most common fermented foods are beer, wine, vinegar, soy sauce, cheese, and even some teas. Fermentation of tea is often referred to as the process of oxidation of catechins in leaves with the participation of oxidase enzymes. The color and taste of tea (from white and green to black) depends on its duration. But there are also fermented teas, in the production of which microorganisms are involved – for example, pu-erh tea.
How exactly does fermentation take place?
Different products do this in different ways. However, all methods of fermentation have one thing in common: the process occurs as if “by itself”, the human task is only to start and control it. The microbial culture is either added to the product on purpose, or it is “launched” there itself.
The yeast settles on the surface of the fruit rind without any human intervention.
In cheese making, in addition to lactic acid fermentation, rennet is used. Rennet is a digestive enzyme obtained from the stomachs of calves or sheep. Although these animals are not specifically killed for their rennet; rather, they are killed for the sake of meat production, more and more people refuse to eat such food. Therefore, more and more manufacturers are using non-animal rennet (sometimes referred to as microbial enzymes) to make cheese that is safe for vegetarians.
That is, fermentation is when products go bad?
Not really. Although food degrades substances, this does not mean that they become unfit for human consumption. It all depends on which microorganisms will prevail. Fermentation often produces natural preservatives (such as lactic acid) that prevent the growth of putrefactive bacteria.
The fine line between gourmet and rancid is the reason why many are afraid of fermentation. What most fermented foods have in common is that they taste and smell much brighter and sharper than raw ingredients. Therefore, exotic fermented foods seem especially difficult to us; you need to get used to their taste and smell. For example, not everyone likes fermented olives from the first bite. However, they later find them adorable.
What is most commonly fermented?
Fermented milk products include kefir, yogurt, sour cream, and many other regional options. All Asian cuisine is based on umami (savoriness) – the taste of glutamic acid, which increases in various foods during fermentation. Umami is considered the “fifth taste”: it is present in soy, fish and oyster sauces, as well as in miso paste.
Countless types of fermented soybeans are consumed in Asia. Depending on which bacterial or fungal cultures are involved in processing, they can acquire radically different flavors, from a delicate nutty, like in the Indonesian “nougat” – tempe, to a bright chocolate dessert, like Japanese fermented natto beans.
It’s unusual. The beauty of fermentation is that it allows you to develop and improve familiar and common foods. For enthusiasts and chefs alike, this is a way to discover new facets of already well-known ingredients.
In addition, it is always an experiment tied to specific conditions. By equipping his own workshop or laboratory, the chef creates a unique environment that cannot be repeated. That is, the fermentation technology really helps to create new products. Vegetarian cheeses and yoghurts, concentrated sauces and condiments, fermented vegetables and fruits are all delicate work, and the result is unique every time.
Fermented foods are considered to be very healthy. This is true?
One of the reasons why fermented foods are so popular is their reputation as “superfoods”. Kefir, kimchi, yogurt, and miso paste all have a variety of health benefits, from improving digestion to boosting immunity, as they are a natural source of probiotics. Many fermented foods are rich in one of the most important probiotic groups, lactobacilli.
What can be fermented at home?
Better to start with vegetables or dairy products. Despite the fact that the simplest fermentation technologies are reduced to the principle of “put and wait what will happen”, you still need to act according to the rules. As a source, you can use the fundamental work of Sandor Katz “The Art of Fermentation”. The book covers all food groups and how they are fermented, and gives an insight into the history of the method. Sandor himself also recommends starting with the simplest recipes for fermenting vegetables – beets, cabbage, carrots.
Another easy way to try homemade fermentation is to make yogurt, kefir, or sour cream. Starter cultures are easy to buy online, either from Amazon or iHerb, or from grocery stores or pharmacies. In large international online stores, you can also find starter cultures for more complex fermentation experiments, such as homemade miso, tempeh or natto.
However, making homemade cheese is not easy and requires more sophisticated equipment.
Are there any precautions?
Yes. It is very important that soil particles do not get into fermented foods. If contaminated food gets into a tightly closed container, it can lead to botulism – poisoning with botulinum toxin, which is produced by one of the soil bacteria in the absence of oxygen. The Latin word botula means sausage – it was the consumption of blood sausage that led to the first documented case of botulism in the 18th century. But it is not only handmade sausage that is dangerous: the insidious microbe can live in a variety of products, multiplying where there is no access to oxygen – most often it is home canned food.
Fermentation and pickling are not the same thing. Both are ancient methods of food preservation. The confusion arises from the fact that the categories actually overlap with each other. Some fermented foods are pickled and some are fermented.