The production of sauerkraut dates back to the ancient Greeks. Today, sauerkraut is famous around the world as a typical German dish. It is usually served as a side or used as a filling in sandwiches.
In sauerkraut and white cabbage, ascorbic acid is also bound in the form of ascorbic acids A and B (C-2-scatyl-L-ascorbic acid). If the vegetables are cooked, the molecules decompose into L-ascorbic acid and 3-hydroxyindole. Sauerkraut therefore contains more vitamin C when cooked than raw. However, cooking for too long destroys the vitamin.2
It is becoming increasingly easy to buy raw sauerkraut, but it’s important to check if it is pasteurized or not. Some producers label their sauerkraut as raw even if it is pasteurized. However, pasteurized sauerkraut is not raw because it has been heated at high temperatures. If it isn’t pasteurized, an open package of sauerkraut loses flavor within three days.
Sauerkraut juice is a vegetable juice made from raw sauerkraut. Sauerkraut juice contains high levels of vitamin C, lactic acid, and live lactic acid bacteria. It is known for its ability to stimulate digestion.
Making homemade sauerkraut:Wash the white cabbage and cut off any damaged or discolored pieces as well as the outer layer. Finely cut the cabbage into thin strips using a vegetable slicer. Make sure to use the slicer carefully as it usually has two blades, one behind the other, whereas a cucumber slicer only has one. It works well to place a wash basin or plastic baby bathtub underneath the slicer. To slice the last part of a head of cabbage, simply use a knife.
You can also add some carrots (about 5 %) in order to obtain a sweeter flavor and more color. In addition, you can add mustard seed, caraway seed, peppercorns, allspice berries, coriander seeds, bay leaves, and juniper berries according to taste. White wine is used to flavor wine sauerkraut. For 9 kg of sauerkraut, you only need a few teaspoons of these ingredients, and they should be mixed in well. Add a few horseradish leaves for a little extra zing.
Add all of the ingredients to the basin and mix well. Add a minimum of 1 % to a maximum of 1.5 % salt. Adding a little salt will make the sauerkraut more flavorful. Let rest for about an hour so that the salt can begin to draw the juice out of the cabbage.
When liquid begins to form, place in a container and press down well. To do so, you can use a wooden cabbage tamper or meat hammer. This will cause more juice to be released from the cabbage — enough to cover the cabbage. The lactic acid necessary for fermentation are in the cabbage and the air.
It is important that the brine cover the sauerkraut entirely during the fermentation period of 4–6 weeks. If it doesn’t, instead of lactic acid fermentation you will end up with mold. To avoid this from happening, place a floating lid on top of the sauerkraut and a weight on top of the lid — or two half-circle stone weights with a hole in the middle. The lid should not be too far from the edge of the container, but the lid should be able to move freely. It is best if you have a lid with holes so that some of the fluid can flow on top of the lid.
A fine white layer, like jelly, will form. Skim this off occasionally, adding a little extra salt water that is saltier than the sauerkraut mixture (e.g., 3–4 tablespoons to 1 liter) because the layers do not mix.
We recommend making smaller batches of sauerkraut on a regular basis. For your first attempt, it works well to use a canning jar with a rubber ring top, for example, a weck jar. Weck jars were first produced in 1895 by the company Weck in Germany and were the first jars of their type to be brought onto the market. They are airtight and work well to preserve jam and other products.
If you do this for a while and then want to make larger batches, try using a fermentation crock with a water channel that serves as an airtight seal. After fermentation, you can then store the sauerkraut in the crock.
Make sure not to fill the container all the way to the top because carbon dioxide can cause foam to form and the contents will overflow. Filling the water channel of the ceramic crock with vinegar water helps to protect against mold. When you add additional water, check that the vinegar water does not become too diluted. In addition, clean the container with vinegar before using.
The best time to make sauerkraut is in the fall because you can buy white cabbage in bulk for cheaper and then eat the sauerkraut during the winter. It should be stored in a cool place, for example, in the basement at about 10 °C.
For a 10-liter fermentation crock, you will need about 9 kilograms of cabbage. This means that you should buy a little more than 11 kilograms to compensate for the parts that you will remove.
Guidelines for making homemade sauerkraut:
Fermentation phases: All of the bacteria needed for fermentation are present in the cabbage from the beggining. The transitions between the phases are automatic (the acidic content determines which types of bacteria dominate). You do not need to add any bacteria cultures. It is just important that there is enough salt (approx. 1.5 %) and that oxygen is excluded. Under these conditions, the right bacteria will grow at the right time and almost nothing can go wrong.
Please note: It works best to use a canning jar with a rubber ring top and clip lock. In the case of too much pressure, CO2 can then automatically escape. Thanks to fermentation, no yeast or mold can form since the top of the container contains virtually only CO2.
Be careful when adding honey or wine as these can disturb the fermentation process. Honey contains antimicrobial substances and wine sulfates that both inhibit lactic acid bacteria. It is better to wait until after fermentation to add extra ingredients. In the industrial production of wine sauerkraut, the wine isn’t added until the filling step after fermentation. Incidentally, wine contains added sulfates so that fermentation by lactic acid bacteria cannot take place. Unfortunately, these sulfates also have to be added to organic wine.
Sauerkraut is rich in lactic acid, minerals, and vitamins A, B, and C. Along with the other vegetables in the cabbage family, sauerkraut can be grown locally and is a good source of vitamin C in the winter. Sauerkraut has relatively few calories at about 80 kJ/100 g (19 kcal/100 g), is virtually fat-free, and contains 3 to 4 % carbohydrates and 1 to 2 % protein.
Many reference books list sauerkraut as having relatively high amounts of vitamin K, but according to a recent study sponsored by the German heart foundation (Deutschen Herzstiftung), it actually only contains an average of 7.7 μg/100 g.2
Since bacteria die in the acidic stomach environment, it is controversial whether or not eating raw sauerkraut (unpasteurized since pasteurization takes place at temperatures of 75 to 90 °C) that contains live lactic acid bacteria positively influences the intestinal flora. However, the pH value of the gastric mucosa is not so low.
Some studies (e.g., at Giessen University) have shown that sauerkraut has a preventive effect against colon cancer, and Finnish studies conclude that isothiocyanates in sauerkraut slow down "cancergrowth" in the lungs, breast, liver, and intestines in animal subjects.
Industrial sauerkraut is usually made using white cabbage or pointed cabbage that is naturally fermented in airtight fermentation silos. Fermentation is limited by adding 1.5 % salt.
During the first three days, yeasts and acetic acid bacteria develop and then consume the remaining oxygen and produce ethanol, acids, and esters. Next, heterofermentative lactic acid bacteria (e.g., Leuconostoc species such as Leuconostoc mesenteroides) are added. These form lactic acid, acetic acid, "mannitolum", and carbon dioxide, which lowers the pH. This inhibits the "growing" of undesirable foreign organisms such as clostridia. As soon as the lactic acid has risen to 2 %, the pH also inhibits the lactic acid bacteria. The ethanol esterifies with acids, which is important for the flavor of the sauerkraut. This process takes another three days.
Depending on the temperature, phase three lasts between 3 to 6 weeks. At the beginning, homofermentative lactic acid bacteria are added, which are even more acid-tolerant (e.g., Lactobacillus species such as Lactobacillus brevis). The shelf life of sauerkraut can be increased by adding ascorbic acid (vitamin C) at the end of the fermentation process.