As we began to farm and harvest, we realised that we also needed to learn how to preserve food for longer. There were times when we had too much of a vegetable and there were times when we had nothing. There were also times when we could not farm or harvest because of the rains. So it was important that we optimise the output in the months favourable for farming and store the food for longer while retaining their nutritive value and vitality.
We had learnt about cold storage where the food is kept dry, cold and in dark to slow down the activity of the microbes and their enzymes to keep the food fresh for longer. But it is difficult to achieve the ideal conditions with limited technology and we needed a method that was easy and did not require major investment.
Alternatively, by guiding the activity of the beneficial microorganisms through fermentation, we can prevent decomposition and create decalicies.
Fermentation is essentially transformation of nutrients by micro-organisms and their enzymes. These microorganisms (bacteria or fungi) can either occur on the food naturally (wild fermentation) or can be introduced as starter cultures (an established ferment or microbial community).
Every raw food (fruits, vegetables, milk etc.) is host to a diversity of microorganisms. By manipulating the environment, we can favour the desirable microorganism to transform our food into a more stable, nutritious form with a characteristic ferment flavour, which is usually very different from the original food.
Also, The fermenting bacteria/fungi are cultured in an anaerobic (without air/oxygen) environment.Thus, fermentation is a process of producing energy from nutrients without oxygen.
Fermentation has been used since thousands of years to preserve and add value to the raw food products. The practices of fermentation have evolved over time through close observation of natural phenomenon and trail and error, and have been passed on through generations, some of which are commonly known, some are culinary secrets and some are forgotten and lost.
HOW TO START:
With a little patience and understanding, anybody can learn to work with these microscopic beings, keep them happy and alive, so that they can protect our food and its goodness and flavour for longer.
Preservation by acidification (by lactic acid or acetic acid) is the most common way used in fermentation. The acidifying bacteria, besides crowding out the other bacteria, also produce inhibitory substances such as hydrogen peroxide and other antibacterial compounds, thus creating a selective environment which limits the growth of pathogenic microorganisms.
All vegetables are pre inoculated with native lactic acid bacteria, enough to initiate fermentation. Hence,in case of vegetables we do not need a started ferment. However, juices from old ferments can be used to speed up the process.
We have tried and relished fermented cabbages, carrots, beetroots, garlics, radishes, radish leaves, broccolis, turnips, kohlrabis and plums.
Vegetables/fruits are cut into small pieces to increase the surface area of the vegetable/fruit and increase the area of activity of the fermenting microbes.
However, this is not absolutely important for fermentation and good fermentation can be achieved in full fruits and vegetables.
Salting and the amount of salt will depend on personal preferences. Salting is not necessary for fermentation.
Though the Salt helps in following ways:
- Salt pulls out water from the vegetables, makes them crispier and helps them stay crisp.
- Salinity creates a selective environment and allows only salt tolerant bacteria to flourish like- lactic acid bacteria.
- Salt slows down fermentation thus extending its potential for preservation.
Iodised salts can be used, but use of rock salts, marine salts which have high mineral content are also recommended.
- Add salt to taste to the cut vegetables and mix with hand. To begin with, you can try 2-3 jars with different amounts of salts and improvise based on your taste and fermentation process in your local climate.
Salt slows down fermentation, so more salt is recommended during summers (when the temperature will favour rapid fermentation) and less salt during winters (when the fermentation activity is already slow).
- The salted vegetables can be left covered with a piece of cloth for 2-3 days. The objective is to get as much water out of the vegetables as possible.
After the vegetables would have lost a lot of water and they are somewhat submerged in their own juice, they are ready to be packed. If the vegetables taste too salty, they can be lightly washed with water first before packing. Also, other spices can be added while packing.
- Take a handful of the cut vegetables and squeeze it between your palm such that the juice falls back in the container. Fill this dry vegetable in the jar.
- As you keep doing this, keep pounding the vegetables down in the jar. Add spices, flavours as you build layers.
- In the end, put the juice of the vegetables in the jar such that the vegetables are completely submerged in the juice.
Fermentation is an anaerobic process, so it necessary to cut off access from oxygen. Keeping the vegetables submerged in their juices helps in this.
- If the juice is not sufficient, add water.
- Make sure to leave some space at the top of the jar, for the gases (mainly carbon-dixide) released during the fermentation process.
Drinking water is all that is required. However, chlorinated water can be a problem. Chlorine can retard or sometimes even inhibit fermentation. It is recommended to filter or boil the water to remove the chlorine.
Note: More stable forms of chlorine called chloramines cannot be boiled out and require more effective filters.
Ferments need not be kept in complete darkness. They can be stored in a quiet place with access to indirect sunlight.
In India, we also keep the ferments in direct sun for a few days. Not sure about the rationale, but this can be tried and experimented with.
Glass, porcelain, ceramic all are fine. We have our reservations with plastic since the chemicals in the plastic can possibly leach over time into the ferment.
- Releasing the pressure
Fermentation microbes produce carbon dioxide as a product of their metabolism as they feed on the sugar from the raw food (same as our metabolism process). If the fermenting jar is closed with an air tight lid, it is important to pay attention to the jar once every few days and release the co2 build up by opening the lid slightly. Keep the lid loose can also help in releasing the pressure inside the jar. If you close the lid too tight and forget your jar for weeks or months, they can burst.
Benefits of fermented food:
Through fermentation, the food is preserved but its composition is changed due to the digestive processes of the organisms involved. The compounds and minerals are digested into more simple and available forms. This makes it easier for our body to assimilate these nutrients which are already pre-digested by the organisms. Fermentation is also known to enhance nutrition of the raw food and creation of unique micro-nutrients. That is why yogurt or kimchi (Korean pickles) are considered more nutritious than plain milk or vegetables. Also, our gut is home to millions of microorganisms that help us in digestion, assimilation and even detoxification. These are collectively known as microflora. By eating fermented foods, we increase the diversity of the microflora, boost its strength and our own metabolic capacity and immunity.
Life of a ferment
Fermentation will not save food forever. Like any other natural process, how long a ferment will last will depend on the food which is being fermented, the, water and its salt content, temperature and humidity and the way it is stored. Also, different people will have different tastes. Some can enjoy a more aged ferment, while others won’t. Fermented foods are alive and always changing, the microbes and their enzymes can over time transform changing the texture, colour and flavour of the food. This happens faster if the salt content is less and/or in summers than with higher salt content and/or in winters.
It is best to taste your ferments as they grow old, understand how their favours change and what are your own tastes and tolerances.
Fermentation is a simple way of collaborating with microorganisms and taking control of your own food security. At the same time, it is fun and can lead to some incredibly delicious discoveries. No two ferments will ever taste the same and you are always surprised by your own creativity and this magical phenomenon of nature.
It is only with the understanding this dynamic nature of fermented foods, human beings have been able to create a variety of ways of fermentation and delicious recipes all over the world to preserve their food for times of scarcity.
Sandor Ellix Katz, The Art of Fermentation