Homemade sauerkraut recipes are simple but far exceeds most commercial sauerkraut products. In addition, you can adjust the recipe to fit your own taste adding herbs, spices or even other vegetables.
Here I will describe a basic sauerkraut recipe and how the fermenting process works. This is the same process as for most other vegetables you like to ferment.
Choosing sauerkraut cabbage
It doesn’t seem to matter that much which cabbage you get; I’ve tried with fresh and older cabbage, organic and non-organic: they all seem to work well. However, organic cabbage will have less harmful chemicals on them and might contain more nutrients.
Aim for cabbage that has tightly packed leaves. You can use both green and red cabbage, or you can mix both. Red cabbage adds a beautiful color.
Avoid washing the vegetables in bleach or similar; you don’t want to kill off the natural, healthy bacteria that should start and dominate the fermentation process.
Shredding the cabbage
The shredded cabbage is placed in a bowl and a little salt is usually added. If you want to add some other herbs or greens, this is a good time to do it. I sometimes add one or two apples, cumin, a few carrots or perhaps some cilantro or coriander leaves. This add taste and makes your sauerkraut look appealing.
Now mechanical pressure is applied to the cabbage to extract the juice which contains fermentable sugars and other nutrients suitable for microbial activity. You can squeeze the cabbage with you hands or use some instrument.
Put the vegetables in jars
Put the cabbage in clean jars. Check brine levels as you want all the vegetables to be covered and emerged in juice. Don’t screw the lids on too tight as gas will form during fermentation and pressure will build in the jars. This is only important during the time you have the jars in room temperature for about seven days.
The sauerkraut fermentation process
Healthy lactic acid bacteria are primarily involved in sauerkraut fermentation. But besides the healthy probiotic bacteria, there might be many undesirable microorganisms present on cabbage (and most other vegetables) and these can interfere with the sauerkraut process if allowed to multiply unchecked.
The quality of the final product depends largely on how well the undesirable bacteria are controlled during fermentation. Some organisms produce unpleasant odors and flavors and can completely spoil your sauerkraut.
NOTE: If you use a starter culture, you don’t have to add salt. But if you want a little salt anyway, then use Himalayan salt or sea salt
Tip: Run some of the cabbage through a juicer to get more brine in the jars.
The major steps in the sauerkraut fermentation process:
- The first micro-organisms to start working are the gas-producing cocci L. Mesenteroides. These microbes produce acids and when the acidity reaches 0.25 to 0.3%, these bacteria slow down and begin to die off, although their enzymes continue to function.
- Now the work is continued by the lactobacilli (L. plantarum and L. Cucumeris) until an acidity level of 1.5 to 2% is attained. The high salt concentration and low temperature inhibit these bacteria to some extent.
- Finally, L. pentoaceticus continues the fermentation, bringing the acidity to 2 to 2.5% thus completing the fermentation.
Optimal temperature for fermentation
You should try to keep the temperature for sauerkraut fermentation around 70 degrees (21ºC). Even a few degrees more or less can change the activity of the microbial process and affect the quality. Therefore, you must control the temperature to succeed. A temperature of 64 to 72 (18º to 22º C) is most desirable for initiating fermentation since this is the optimum temperature range for the growth and metabolism of L. mesenteroides. Temperatures above 72 degrees (22ºC) favor the growth of Lactobacillus species.
Traditionally salt has been very important to correctly start the sauerkraut process as it will affect the quality of the sauerkraut. Too much salt may prevent the good bacteria to grow, even though it may make the sauerkraut firmer or crispier. Salt is can also extract juice from the cabbage (or other vegetables), thus creating a favorable environment for the desired bacteria.
Normally, a salt concentration of 2.0 to 2.5% is best because the lactobacilli are slightly inhibited, but cocci are not affected. But this salt concentration can disturb desirable organisms more than the undesirable since the bad organisms can tolerate salt concentrations up to between 5 and 7%. Therefore, it is mostly the acidic environment created by the lactobacilli that keep the bad bacteria at bay, rather than the addition of salt.
Use of cultures starters
A culture starter can…
- produce sauerkraut of consistent quality
- speed up the fermentation process
- greatly increase the amount of probiotic bacteria
- omit the need of salt at the start of the process (you can add salt when fermentation is done, just before you eat)
What kind of starters can be used?
- Starters traditionally used for milk fermentation, such as streptococcus lactis are OK
- You can also use some juice from previous sauerkraut fermentations as a starter culture, even though this is a little risky (see note below)
- Use a starter containing several healthy bacteria strains. This is one of the best ways since it greatly increases the amount of probiotic bacteria.
NOTE: About using old juice from an earlier batch
The success of using old juice depends on the types of organisms present in the juice and its acidity. If the starter juice has an acidity of 0.3% or more, it results in poor quality sauerkraut. This is because the cocci which would normally initiate fermentation are suppressed by the high acidity, leaving the bacilli with sole responsibility for fermentation.
If the starter juice has an acidity of 0.25% or less, the kraut produced is normal, but there do not appear to be any beneficial effects of adding this juice. Often, the use of old juice produces sauerkraut which has a softer texture than normal.
What does the final sauerkraut product contain?
- lactic acid
- large amounts of probiotic bacteria (if you use a starter culture like Body Ecology, you can have trillions of probiotic CFU in a few tablespoons of sauerkraut; that’s like a whole probiotics supplement container in one tablespoon!)
- small amounts of acetic and propionic acids
- a mixture of gases, mostly carbon dioxide
- small amounts of alcohol
- a mixture of aromatic esters
- most fermented nutrients, vitamins, and enzymes become easy for your body to assimilate
All these substances together contribute to the characteristic flavor of sauerkraut. The acidity helps to control the growth of spoilage and putrefactive organisms and contributes to a very long shelf life.
Common problems with fermentation
The main reason for problems in the sauerkraut process is due to the presence of certain micro-organisms; they break down protein and produce undesirable flavor and texture changes. But this can easily be solved by following the advice in this post and create a normal fermentation.
Why is the sauerkraut too soft?
- Too much air
- Too little salt (usually does not apply if you use a starter culture)
- Wrong temperature
Whenever the desired sequence of bacterial growth is changed or disturbed, it often results in soft vegetables. The lactobacilli seem break down the cabbage and make it soft. Too high temperature and a too little salt content promotes the growth of lactobacilli because they are sensitive to higher concentrations of salt. The normal concentration of salt used in sauerkraut slightly prevents the lactobacilli, but does not disturb the cocci. However, a too low salt content can make the lactobacilli grow too fast at the start and can disturb the normal sequence of fermentation.
Dark colored sauerkraut
The reason for this is unwanted organisms during the fermentation process. For example, an uneven distribution of salt tends to disturb the good, healthy organisms but also allow the undesirable salt tolerant organisms to flourish.
In addition, a common problem that I’ve had many times is a too low level of juice. This allow some bacteria and yeasts to grow on the surface of the vegetables not completely covered by juice. This cause discoloring and a bad flavor. Also, if the fermentation temperature is too high, it can stimulate the growth of undesirable microflora, which results in a darkened color.
Tips: If you run some of the cabbage in a juicer you’ll be able to cover the vegetables completely in the jars. After this when fermentation is complete and you put the jars in a cool place, be sure to check the lever of the brine; it has a tendency to get low quickly in the beginning. You cannot save the freshly pressed vegetable juice this long so just use boiled water that has cooled down.
This is often caused by a group of yeasts that produce an intense red pigment in the juice and on the surface of the cabbage. The reason is an uneven distribution of or an excessive concentration of salt, both of which allow yeast to multiply. If conditions are optimal for normal fermentation, these spoilage yeasts are suppressed.