Sauerkraut is fermented cabbage, which preserves the
cabbage and has been consumed as a traditional food in many cultures for hundreds if not thousands of years. Sauerkraut is probiotic-rich, that is rich in beneficial bacteria –
friendly microorganisms which help to colonize the gut, train the immune system
and manufacture vitamins in the digestive tract. The fermenting process
increases vitamin C, vitamin B and food enzymes.
Homemade sauerkraut takes time – a week at least, and maybe months, depending on your climate.
What kind of container should I use? I began fermenting sauerkraut in mason jars for want of something better and this method has been fine for me because I do only small amounts at a time. There are specialized jars which are more suited if you are doing large quantities.
It is important to remember that fermentation is an anaerobic process (it does not need oxygen), so air must be excluded. However, the container should not be sealed, because accumulated gasses also need to escape. When you create a true anaerobic environment by using the right crock or fermentation device, this results in better sauerkraut, less contamination and fewer failed batches. You can pour a layer of virgin olive oil on top of your sauerkraut to allow gasses to escape, but not allow oxygen to enter.
Here is a link to a site which will tell you all you will ever need to know about keeping your sauerkraut anaerobic, and the kind of containers that work the best.
The ideal temperature for fermenting sauerkraut is around 18 to 22 degrees C as room temperature, and this might be hard to achieve in Summer or in the tropics. So you might need to put it in the fridge after three days under these circumstances, which will slow down the fermentation process.
Now for the recipe:
- Core and very finely shred the cabbage - any quantity will do, but probably not less than 500 gms. If you have a very big cabbage, you might only want to use a quarter, until you gain some confidence, then make it in bulk and find lots of opportunities to use it every day.
- Put the shredded cabbage in a large bowl with some caraway seeds and salt. For 500gms of cabbage about 1 T good sea salt, and 1 teaspoon caraway seeds.
- Pound the cabbage with your fist, a wooden mallet, or other implement, until the cabbage is limp and has yielded quite a lot of juice.
- Pack the cabbage mixture firmly into your jar, making sure that air bubbles are excluded, that the jar is filled no more than 2/3 full, and that the juice covers the bruised cabbage.
- Pour a layer of olive oil over this, to protect it from the air, but allow gasses to escape.
- Leave on the counter top for somewhere between 1 week and one month. A lot of bubbling will happen, and the cabbage must remain under the surface of the liquid the whole time. In the tropics where I live, this process happens very quickly, and unless it is winter, I put mine in the fridge after 3 or 4 days.
- You can begin to eat the sauerkraut when the major part of the bubbling finishes, but the lactobacillus will continue to multiply for some time.
In one study of bacteria collected from four commercial sauerkraut fermentations, a total of 686 bacterium were discovered although not all of them are in the sauerkraut at the same time.
This means if you're someone who makes your own sauerkraut and eats from it as it is fermenting, you will be getting a continually changing supply of lactic acid bacteria.
It is well established that strains from within the same family can differ in their health promoting effect so this enormous diversity is possibly the strongest of the benefits of sauerkraut.
Bacteria found included:
• Weissella species
• Lactobacillus plantarum
• Lactobacillus curvatus
• Lactobacillus sakei
• Lactobacillus paraplantarum
• Lactobacillus coryniformis
• Lactobacillus brevis
• Lactococcus lactis subsp lactis
• Leuconostoc mesenteroides
• Leuconostoc fallax
• Leuconostoc citreum
• Leuconostoc argentinum
• Pediococcus pentosaceus
Leuconostoc mesenteroides is the bacteria that gets the fermentation started by changing the sugars in the cabbage (glucose and fructose) to lactic acid, acetic acid, ethanol, CO2, and other flavour compounds.
As the process continues the production of the acids lower the pH of the sauerkraut and stop harmful bacteria from getting a foothold.
Eventually the L mesenteroides will die as conditions within the fermenting cabbage "brew" become unfavourable for its growth.
The CO2 makes the ferment airless and this encourages the growth of the lactic acid bacteria such as L plantarum who enjoy this condition and can exist in a highly acidic environment.
L plantarum becomes the dominant species of good bacteria after the first week of fermentation and by 2 weeks will sometimes be the only species present. I say "sometimes" because each brew of sauerkraut differs. That's the beauty of it all!
It is only through the proper succession of these lactic acid bacteria that the quality and safety of the sauerkraut can be assured.
Lactobacillus plantarum is the species that you're likely interested in the most. Some strains of this useful bacteria are probiotic and can be found in supplements and a variety of foods.
The contents of the “Mad Millie” Aromatic Mesophilic Culture, which I added to my latest batch, are:
Lactococcus lactis subspecies lactis
Lactococcus lactis subspecies cremoris,
Lactococcus lactis subsp lactis biovar diacetylactis
This selection is used to make cheese as well as to ferment vegetables.