Sauerkraut can be made from white cabbage using lactic acid fermentation. However, fermentation is also suitable for preserving many other types of vegetables and is very healthy. How does it work?
Fermentation is a very old and simple method of preserving vegetables. Here it is mainly used in the production of sauerkraut, but the well-known Korean national dish kimchi is also based on this form of fermentation.
There are different types of fermentation, with vegetables the so-called lactic acid fermentation is usually used. The fermentation creates an acidic environment. Mold or unwanted bacteria that would spoil the vegetables cannot exist in it. The vegetables will keep for a very long time. At the same time, additional vitamins are produced, which is why fermented vegetables are particularly healthy. Foods fermented with lactic acid also promote a favorable and healthy intestinal flora.
Ferment your own vegetables
Fermenting is fairly easy but requires a bit of patience. In principle, all types of vegetables are suitable, but vegetables that are not too soft, such as cabbage, root vegetables, beans, beetroot, pumpkin, or peppers, work particularly well. But softer vegetables can also be fermented, but they may become so soft that they fall apart.
First, wash the vegetables and cut them into small pieces or slice them into fine strips. Then place in a large bowl and mix with salt. Rule of thumb: Add about two to four percent of the amount of salt in the vegetables, i.e. about 20 to 40 grams of salt for 1 kilo of vegetables. Then knead, press, or stamp the vegetables vigorously with the salt so that enough juice comes out.
Vegetables must be completely covered by the brine
Then fill the vegetables with the liquid in airtight, clean, pre-boiled jars or screw-top jars. Squeeze the vegetables tightly again and again so that as little air as possible remains in the gaps.
Make sure the vegetables stay under the brine and don’t come into contact with the air. Finally, if necessary, cover with cabbage or other vegetable leaf and weigh down with a weight – for example, clean glass marbles or a special fermentation stone. It is very important that the vegetables remain completely covered with the liquid. If the liquid is not enough, top up with a boiled salt solution (20 to 30 grams of salt per liter of water). Close the jar, but only tight enough to allow the gases that form to escape. In the event that something overflows, place the glasses on saucers during the fermentation process.
Tip: Special fermentation pots and jars with fermentation lids are particularly well suited for lactic acid fermentation, where the gases can escape but no oxygen can penetrate.
The longer the vegetable ferments, the more acidic it becomes
The jars must remain at room temperature for at least five to seven days. During this time, the lactic acid bacteria convert the sugar in the vegetables into lactic acid, which can be seen in the small bubbles that form. The brine becomes slightly cloudy. Later, the vegetables can also be stored cooler (at 15 to 18 degrees). The longer it ferments, the more acidic it becomes. Putting the jars in the fridge slows down the fermentation process. When the best acidity is reached depends on experience and personal taste.
Fermenting: Avoid common mistakes
If the lid of the screw-top jar bulges, this is a sign that the gases cannot escape properly. In this case, carefully unscrew the jar a little bit and smell it: as long as the smell is good, the vegetables are fine.
If you find white deposits or mold when you open a jar, this indicates that the vegetable was not airtight. Harmful bacteria or mold could then settle. This can also happen if the glasses or hands were not really clean. Please do not eat such spoiled vegetables, but clean the jars thoroughly and sterilize them in the oven at around 120 degrees for around 15 minutes.