Fermentation - What Is It

Today, the word " fermented " appears on the menu of every decent and more or less progressive restaurant, and dishes with fermented ingredients are characterized by a rich and bright taste. Let's find out what makes foods fermented and how it happens.

Fermentation is

Controlled process of spoilage of products . This is not a very scientific, but understandable explanation. If we describe the chemical processes that occur during fermentation , then the meaning is as follows. Special microorganisms produced either by the product itself , or appear with the help of an added activator from the outside, secrete enzymes. They, in turn, start the process of splitting complex chemical compounds in the product into simpler ones. That is, in fact, complex chains are decomposed into their constituent parts, namely simple sugars, free amino acids, etc.

We are all familiar with the fermentation process in one way or another. Fermentation is part of the natural fermentation process. It is usually stopped before fermentation in the product is complete.

And if we speak in terms of taste, then in the original product there are molecules whose taste the brain cannot directly interpret as sweet, sour, salty, bitter or umami. In the fermentation process, these molecules are broken down into simpler elements, which precisely provide specific tastes. Thus, fermentation makes the product clearer, the taste becomes brighter and clearer.

The process must be controlled so that, in addition to useful and necessary for fermentation , pathogenic microorganisms do not appear. The condition necessary for this is the absence or lack of oxygen. Also, for natural fermentation , without the addition of ready-made enzymes, a certain amount of salt is needed.

A simple example: if you put a lot of fresh meat in a slide and leave it in the air, then over time the pieces that are in contact with the air will rot, and those inside, in the presence of salt, will ferment because they did not have contact with the air.

You may have been fermenting foods for a long time

In fact, in our everyday life, we come across fermented products much more often than it seems. Kefir, cheese, all types of alcohol, vinegar, coffee, tea, soy sauce, jamon, kimchi - these are all products of fermentation .

That is, fermentation is not a process that can only take place in a restaurant kitchen. This process is widespread: both on an industrial scale and at home. Often it seems so obvious to us that we do not think about the fact that fermentation was used to produce this or that product . Almost always, when we prepare vegetables for the winter or prepare food for cooking, we engage in fermentation . For example, pickling cabbage, pickling cucumbers in brine or meat for barbecue is also a certain kind of fermentation .

Where do microorganisms come from?

Microorganisms responsible for fermentation may initially be present in or on the product , or may be added to it. In the first case, we are talking about non-inoculated fermentation , in the second - about inoculated, that is, provided with the necessary enzyme from the outside. Carriers of such enzymes can be bacteria or fungi. There is a large number of beneficial bacteria and good mushrooms. Sourdough bread, kefir, vinegar - products of inoculated fermentation .

For example, when cabbage is fermented under the influence of lactic acid bacteria, lactic acid is produced. They are available together with the raw material - the cabbage itself. After all, any product is alive, it has its own natural microflora, which consists of bacteria. That is why it is important not to wash the products too thoroughly before fermentation - sterile products for this process are not interesting.

An example of inoculated fermentation is the production of many varieties of cheese. In this process, lactic acid bacteria, initially present in the raw material - milk, and rennet, and mold cultures, mushrooms, which are responsible for the individuality of cheese, are involved. They are specially bred, grown and stored. One culture is used for Camembert, another for Roquefort, and so on.

Important conditions for fermentation

The fermentation process likes stability and is sensitive to environmental changes. Let's take as an example the fermentation of solid products in the absence of air, without taking into account the fermentation of liquids and aerobic fermentation . To start the process with solid products , it is necessary to ensure the absence of air and the presence of salt.

The lack of contact of the product with air can be achieved mainly in 3 ways: placing the product in a vacuum using special packaging, creating a similar climate by placing the product in a container under the load, or fermenting in a liquid environment.

Salt is required at least 2-3% of the weight of the fermented product , but not more than 8%. At this concentration, it does not prevent the development of beneficial bacteria, but blocks the development of some harmful ones, and at the same time does not overshadow other tastes. However, the main task of salt is the initiation of osmosis, the process of liquid release from the product and the penetration of salt into it. Thus, the fermented product releases juice, and the fermentation process develops.

In addition to the lack of air and the presence of salt, there are other important factors. First, a stable temperature is necessary. In general , fermentation can take place at any temperature up to 45-50 degrees. If it is higher, the beneficial bacteria will die.

But here there is a direct dependence on time: the higher the temperature, the faster fermentation occurs . The result obtained in a short time will differ from a longer one. There are no clear rules: someone considers the optimal temperature for fermentation to be 21-28 degrees, someone - 36-37, and so on. The fermentation period of various products can be from 5 to 10 days.

Secondly, it is necessary to avoid the influence of direct sunlight on the product during fermentation , and it is better to ensure darkness in general - put a vacuum bag or jar in a dark place or wrap it with something.

What happens fermentation

We already know about inoculated and uninoculated fermentation , but there is a classification based on other parameters as well.

First of all, the concepts of primary and secondary fermentation of products should be immediately separated . Primary fermentation is a process in which enzymes are directly formed that convert compounds of sugars, starches, etc. into other elements. With the help of primary fermentation , for example, fermented milk products , sauerkraut, koji (rice or other cereals on the surface of which a special moldy culture grows) are obtained.

Primary fermentation products are used for secondary fermentation . For example, garumi - ancient fish sauces (although they can be prepared not only from fish) - are prepared with the help of salt and koji. Koji is a product of primary fermentation , garum is a product of secondary fermentation.

There are many fermentation options , and some of them are quite difficult to perform and require special equipment. This does not apply to lacto-fermentation - lactic acid fermentation. This is the most accessible and common way of fermenting products . As the name implies, products are fermented under the influence of lactic acid enzymes secreted by lactobacilli. Kefir, sauerkraut, cheese are all products of lactofermentation.

Alcoholic fermentation is a process in which simple sugars in wort or juice break down into carbon dioxide and ethyl alcohol. It can occur independently, but it is often accelerated by adding yeast.

To obtain non-alcoholic beverages through fermentation , various fungi and starters are used, which cause fermentation. The most famous example is the preparation of kombucha on kombucha or kefir.

Unusual fermentation products that can be prepared at home

In addition to the well-known sauerkraut and pickles, there are some fermented products that we usually buy or taste in restaurants, but never think about making them ourselves.

For example, the popular kombucha is actually a drink prepared from the long-known kombucha. Kombucha can be obtained from almost any liquid: tea, juice or coffee. The main thing is that there is a sufficient amount of sugar in the liquid. The most difficult part of this process is to grow and preserve kombucha, as it is quite picky. Also, if kombucha is not made from tea, the process becomes more sensitive to changes in the environment.

Vinegar, like kombucha, can be obtained from almost any juice with sufficient sugar content. First, the juice simply ferments, then yeast is added to it, and after some time ethyl alcohol is formed. The next stage is the production of vinegar in the process of acetic acid fermentation.

Koji - in the original, rice, sown with a moldy culture of Aspergillus rice. If we do not delve into the technological and other details, then the process is quite clear: the rice is boiled, laid out, a thin layer of groats is evenly distributed over the surface, then a sufficient number of koji spores are sprayed on top (seeded). In a moist and warm environment, the spores penetrate into the grain, the mold grows and covers all the grains. This is koji. It has a pleasant taste - umami.

In Asia, koji is widely used: to prepare soy sauce, miso paste, sake and many other products . At home, as well as in a professional kitchen, the range of applications is quite wide: you can dry koji and make croutons, you can add it to broth for a richer taste or grind it and use it as a seasoning. The first step is to buy spores to start experiments.

In addition, if you have experience and certain skills, as well as appropriate bacterial cultures, you can even prepare miso paste, garum, black vegetables and fruits, soy sauce, etc. at home.